Acoustically couple Audio Recording for Cameras with no Microphone Input?

 

If your camera doesn't have an audio input port then recording audio in windy conditions, or when the camera is at a too greater distance to the subject then normally we would consider using an external audio recorder to record the audio and the replace the camera audio track in post processing.

This requires post-synching the audio to keep lip synch correct and can be difficult to achieve perfect synch.

My proof of concept idea for acoustically coupling the audio that is being captured by the audio recorder is fed directly into the camera mic ports by using a apir of ear-buds which are held in very close proximity to the ports

 

 

My proof of concept rig showing the Sennheisser wireless mic system used as the input to the Olympus LS12 audio recorder.

The recorder can be any type which allows monitoring of the audio being recorded via an earphone port.

 

Two earbuds were glued into a shaped piece of aluminium flat bar so that they aligned perfectly over the mic ports of the FZ80/82.

 

 

 

I used "blue-tack" to add additional audio sealing around the plate and provide the mechanical attachment to the camera.

I left the silicone buds on the ear buds to offer some noise reduction as well as  vibration isolation.

 

 

The two 4.5 mm holes are countersunk to provide a larger bonding area for the two silicone buds using a contact adhesive.

 

With better and closed coupling of the earbuds, and the use of better buds with wider frequency response, the system might be able to be developed into a working system.

Now the internal microphones are extremely sensitive and even though I sealed around the microphones to prevent audio crosstalk between the sound from the ambient surroundings I still could record from the internal mics before plugging in the external recorder. When the recorder was on it reduced the gain of the internal mics and it virtually cut off the ambient, Maybe using a similar circuit that I developed for the FZ200 to defeat the AGC would be useful here. One channel would have a 18KHZ signal set at a level that would reduce the amplifier gain and the other channel would be the normal audio. Maybe that is the next phase?

Why is Flash Duration So Important and Why it is Often Never Quoted?

When it comes to measuring flash output power we would normally use a flashmeter.

 

 

 

 

 

I currently use the Sekonic L-478D as it provides both incident daylight and flash power measurements as well as the exposure for HD camera video.

 

It is quite a sophisticated unit and can provide many elements of the exposure such as the light level in LUX or Foot Candles, The EV number, the ratio of flash to ambient light and can be used for either incident or reflected light measurements.

 

What is not captured by this model of flash meter is the “flash duration”.

Flash duration is important if you want to ensure that the flash pulse produced by your electronic Speedlight, studio strobe or camera pop up flash is going to be short enough to “freeze” the action that you are attempting to capture.

 

Now electronic flash units have evolved considerably over the older units and will normally include an IGBT (insulated gate bipolar transistor) in the output from the flash capacitor to the xenon flash tube.

This transistor can cut off the power going to the tube in microseconds by the flash controller. In this way, the power can be controlled going into the tube to create the light output.

Older units would “dump” the whole of the charge on the capacitor into the flash tube. Some units would also “squelch” the output by dumping the charge into a dummy load thus effectively stopping the light output. Both methods we disadvantageous as the charge built up was always fully depleted and required the flash power circuits to charge it back up to the “ready” voltage before the flash could be used again. So even if you only needed a brief output you had to wait many seconds whilst the unit recharged. The modern units only discharge what is needed for the output power level. So, if the exposure required a brief pulse the unit could quickly recharge the partially depleted capacitor back to the full charge very quickly.

 

 

 

 

One of the older flash units which dumped the full charge on the 620uF capacitor, which was probably charged to around 300volts, into the flash tube to create the intense but brief flash light.

 

 

(note if you ever open a flash gun ensure that you discharge the flash capacitor for if the gun was turned off fully charged the high voltage can remain for several days – depending on the quality of the capacitor)

We naturally assume that flash output is indeed very short duration as we have probably seen examples of water drops splashing into water or darts bursting a balloon. In the real world, this can be far from the truth and some flash exposures can be as long as the highest sync of your DSLR or CSC – in the order or 1/200 second.

When the FULL output flash power is required (the one by which the manufacturer quotes the guide number) the flash tube needs to output light for a longer duration than when it is required to output say 1/128 of its power.

In modern flash units, the flash pulse intensity is always the same but the duration of the pulse shortens as we require lower power.

However due to the nature of the discharge of the current through the Xenon gas in the flash tube the intensity/time graph is not linear. In the very first ignition of the gas the light output is very fast to rise to its peak but then there is a longer tailing off in the intensity as the charge on the capacitor falls.

 

 

This is a typical light output from a modern flash unit at full power.

You can see the very sharp rise and slow tail off in the illumination.

You can see that the flash duration is 1/835sec or 1.20 milliseconds.

 

At full power the flash pulse can last as long as 1/200 second on higher powered studio flash units.

If you were wanting to capture any sort of action photography, then this would result in subject motion blurring as we would normally be using exposures in the region of 1/1000 second for this type of photography.

So how do we achieve a shorter flash exposure time? Well we need to shorten the tail off in illumination and we do this with the IGBT that is in series with the flash tube. We can cut off the current flowing through the tube at any instant after it has been switched on. By doing this we can achieve incredibly short pulses of 1/16000 sec or faster. Of course, we have achieved this by effectively reducing the power output to fraction values of the flash units quoted output guide number.

So, how do we know just how long or short the flash duration will be at any given power output level?

Well some manufactures quote the pulse time and on my Godox studio flash units this value is shown on the flash LCD panel.

 

 

 

 

 

 

Here is the display of my Godox AD200 flash unit showing that at 1/128th power the actual flash pulse duration is 1/10526 secs.

 

You might also notice that this is the t0.1 time.

This is the most important parameter to consider when looking at choosing a flash unit for high speed photography.

 

The t0.1 time is the time of the flash output pulse when the output illumination is above 10% of its peak output. That is to say it is most of the “usable” light output.

 

Using the new Sekonic L-858D flash meter, which can record and graph the flash duration, I have recorded the t0.1 and t0.5 flash times for all my main flash units.

Here is the Godox TT350o which is my current recommendation for Panasonic cameras.

 

 

  

Flash power level

t0.1 duration

T0.5 duration

full power 1/1

1/704

1/1960

1/2

1/2210

1/2480

1/4

1/4120

1/5290

1/8

1/6730

1/10100

1/16

1/10300

1/17800

1/32

1/13900

1/27800

1/64

1/20200

1/49400

1/128

1/23400

1/55600

 

 

 

As you can see from these results at full power the Godox TT350o does have a fast exposure pulse of 1/704 seconds. This is typical of a flash unit with this guide number. You can also see how the IGBT cut off the pulse to create this much shorter duration slash pulse.   

 

If you compare that to the much larger TT685o you can see that the full power exposure pulse is much longer as the flash capacitor is much larger and takes longer to totally discharge into the flash tube.

 

 

 

 

Flash power level

t0.1 duration

T0.5 duration

  full power 1/1

1/406

1/1230

 1/2

1/1280

1/1350

1/4

1/2800

1/4170

1/8

1/4780

1/6090

1/16

1/7530

1/11100

1/32

1/12000

1/22200

1/64

1/16500

1/37000

1/128

1/20200

1/49400

 

 

 

So, what can we take from these results? Well if were we using the TT685 flash unit on a Panasonic CSC like the G series camera the flash synch speed is 1/250 sec so this is longer than the full power flash pulse – so there is no problem. 

However, if we used this unit on a bridge camera which can synchronise flash at all the available shutter speeds if we set a shutter speed of 1/500 second (to reduce the ambient light portion of an outdoor flash shoot) then the shutter would cut of the flash duration as well as this is longer than the shutter speed. 

 

This means that you will not have used all the light available from the flash during the exposure.

If you were shooting water droplets splashing into water the setting the flash unit to 1/32 power would give a very brief 1/12000 sec flash pulse.

Electronic Clapperboard.

When using an external audio recorder and capturing video clips it is necessary to synchronise the two components in the post-production edit.

The mechanical clapperboard is traditionally used but I wanted a very portable device. So I thought about a simple Red LED and piezo buzzer in a small enclosure with a 3v button cell and a push button to connect the battery to the LED & piezo buzzer.

 

 

 

 

 

 

 

 

 

The finished project showing the LED, piezo transducer and the pushbutton.

The case has a small hole to allow the sound the emanate from the transducer. On the right the simple schematic of the unit.

Field backup of Camera Images

If you are making a "once in a lifetime" journey to some exotic place, attending some function that cannot be repeated or just want to be sure that you have a backup of the images on your camera memory card then some form of back up is needed.

 

Now if you have a laptop/notebook/netbook then you have the facility to copy the files from the memory card to device (or a locally attached disk drive) but if you are travelling light or don't have such a device what are the options?

 

Well the simplest method, if you have a smartphone, is to use some form of wi-fi transfer to the smartphone.

The problem here is that all cameras aren't enabled with wi-fi (like the FZ200) or some early model of the Panasonic and Canon travel zooms.

There is a solution to this by using wi-fi enabled memory cards like the Toshiba FlashAir

 

 

 

The FlashAir is the SDHC memory card with embedded Wireless LAN functionality.

 

Since FlashAir works as a stand alone Wireless LAN access point, FlashAir embedded devices are able to both send files to and receive files from each other.

FlashAir also retains the normal functionality of an SD card, allowing general Wi-Fi devices like PCs and smartphones to access its contents.

 

You can share data using multiple connections simultaneously. The Access Point created by a FlashAir card can be accessed by several remote hosts at the same time.

 

Any device with an SDHC slot can potentially host a FlashAir card. This implies that the device must be able to handle SD cards with more than a 2GB capacity. If you have already used an SD card that has a capacity greater than 2GB with your device, the FlashAir card will also function in your device.

 

(This SD card has a wireless access point plus a CPU running a web server on Linux. Isn't that amazing?)

 

I'll be taking a closer look at this device in more detail later - there's a lot of possibilities here!

 

The second option is to copy the files to your smartphone.

With Apple iPhones you need a camera connection kit. 

 

If you have an iPhone 5 or later, it needs iOS 9.2 or later. If you have an iPod touch or iPhone 4s, it needs iOS 9.3. If you're using a Lightning to USB 3 Camera Adapter, you need an iPad with iOS 9.3.

 

For Androids an OTG (on the go cable) is needed. ( though its worth checking if your device supports OTG connection)

 

USB OTG is a very useful feature on Android devices, but surprisingly many people don’t even know how to use this feature. Basically, if your Android smartphone or tablet supports USB OTG, then you can connect USB devices such as keyboards, game controllers or a USB flash drive to your device.

 

But how would you determine know whether your device supports USB OTG or not? Right now, not all devices support this feature, as not all come with the necessary hardware and drivers for it. To determine whether your device supports USB OTG capability, you can either try connecting a USB flash drive (using a USB OTG cable) or use this app instead.

 

USB OTG Checker is a free app that quickly checks your Android smartphone or tablet for OTG support. That’s all this app does, after which you can safely uninstall it since you won’t want one more icon on the home screen that you’re never going to use in the future.

 

 

 

 

 

This is the Basic Apple OTG connection kit.

 

IT WILL WORK FINE IF YOU CONNECT YOUR CAMERA VIA THE USB CABLE.

 

If you try to use a card reader that needs more than 100mA then the iPhone will complain that the device is using too much power and will close the import app.

 

Amazon UK affiliate link for product

 

Amazon USA affiliate link for product

 

 

 

 

 

 

 

A later style of this device (third party) allows you to connect your lightning charging cable to this hub to provide additional power to charge your phone at the same time. The same current limit of 100mA still applies

 

Amazon UK affiliate link for product

 

Amazon USA affiliate link for product

 

 

The choice of reader/memory card will affect the current and I'm working on a list of devices which will work. WIP

With the android smartphones you will need to specify whether it with be the USB-C type connector (like on the Huawei Pro, Galaxy S8 S9 Plus Note 8 9,LG V40 G7 G6 Thinq, Google Pixel Slate,Black) or micro USB type.

 

 

 

 

This is a basic USB-C to USB-A OTG connector for late android devices.

 

It can power readers and hubs without any additional power supply as the USB-C specification allows for current draw of up to 2Amps.

 

 

Amazon UK affiliate link

 

Amazon USA affiliate link 

 

 

 

This is the micro USB OTG cable for earlier android devices.

 

 

Amazon UK affiliate link

 

Amazon.com affiliate link

When you plug the camera into the OTG cable the import dialogue should open up top allow you to transfer the files from the camera via the USB cable. Select "PC" when the camera asks for permission to connect.

 

 

 

 

 

 

 

Showing the camera connection kit transferring files over the USB camera connection lead.

Note the PC connection has been selected on the camera.

There are some limitations imposed by this connection method - especially by the Apple IOS. If you have RAW + JPEG enabled then only the both files is copied over to the smartphone however you will only see the JPEG image. When you export the images from the smartphone to your PC both images will be transferred.

 

Import photos and videos IOS version

To import from your SD card or digital camera, follow these steps:

 

Connect the adapter to your iOS device.

Connect your digital camera to the adapter by USB or insert an SD card.

Photos app should automatically open to the Import tab. If it doesn't, open Photos and tap Import.

Tap Import All to import your content, or tap specific images/video, then tap Import.

When the import is complete, you might be asked to Keep or Delete the media on the camera or SD card.

You can import content only to your iPhone, iPad, or iPod touch. You can't export content to an SD card or digital camera.

 

If you don’t see the import option or you don't see the Import tab, follow these steps:

 

Make sure that your digital camera is on and in the correct mode to export images (PC Connection not Pictbridge)

Disconnect the adapter, wait 30 seconds, then reconnect it.

Unplug the digital camera or SD card, wait 30 seconds, then reconnect.

Restart your iOS device and turn your camera off and back on.

If one is available, test with a different digital camera or SD card. If you can import media with a different digital camera or SD card, there might be an issue with the data on the camera or SD card.

SD Card to Hard Disk/SSD

 

The idea of my project was to transfer the files directly from the SD memory card to another storage medium and this could be either a traditional spinning platter disk or the later electronic solid state drive (SSD).

To keep power requirements as low as possible I elected to use a 250GB SSD. Now this could be the USB-SATA3 type drive enclosure or a USB direct connection. The other option was to use one of the m.2 form factor boards (250GB) in a suitable enclosure.

In the end I went for the m.2 form factor board and enclosure just to keep the size down.

 

 

 

 

The complete kit needed for the transfer

 

250GB SSD & Enclosure

OTG Cable

USB 3.0 HUB

USB 3.0 Reader

Powerbank

Android Smartphone

Affiliate Links for the above products

 

OTG cable for USB-C type smartphone Amazon UK     https://amzn.to/2E35Kmz

OTG cable for USB-C type smartphone Amazon USA   https://amzn.to/2Xf506V

 

Micro USB OTG cable smartphone Amazon UK            https://amzn.to/2E6U2Hw

Micro USB OTG cable smartphone Amazon USA          https://amzn.to/2EoXvTj

 

250GB SSD Amazon UK    https://amzn.to/2E8ztKP

250GB SSD Amazon USA  https://amzn.to/2EqojTh

 

Enclosure for above UK    https://amzn.to/2SiFCJK

Enclosure for above USA  https://amzn.to/2T9314J

 

USB 3.0 HUB UK   https://amzn.to/2BOalZL

USB 3.0 HUB with Micro USB OTG  USA      https://amzn.to/2U4CnqO

 

USB 3.0 SD Card Reader UK   https://amzn.to/2E4uknd

USB 3.0 SD Card Reader USA https://amzn.to/2TZ1XxC

 

As only the Android operating system supports access to USB ports I used my Huawei P20 Pro smartphone (although any android phone which supports OTG would work).

These later phones have the advantage of having USB 3.0 OTG ports thus enabling faster transfer speeds.

If you have the earlier phones with micro USB port then it will most likely be USB 2.0 ports and therefore the USB Hub and reader could be purchased as USB 2.0 versions. The 250GB drive will be USB 3.0 but will fall back to USB 2.0 speeds.

Once the OTG cable is plugged in and connected to the USB Hub then when any USB peripheral is plugged into it it will be automatically mounted by the Android filesystem.

Using the "FILES" app on the smartphone to select the DCIM folder (everything within this will be copied) as the source directory, selecting COPY and then creating a new folder (directory) on the SSD as the target directory, navigating to the new folder (directory) and then selcting PASTE to then complete the copy of the whole contents of DCIM over to the SSD

 

My video of this process is detailed in this YouTube Video

 

 

After putting the “kit” together I found a USB 3.0 SD/QXD card reader plus USB port with independent USB channels allowing simultaneous transfer to each device.

 

 

 

 

The new setup is a lot more portable.

 

I switched out the m.2 enclosure for a standard USB-Sata 3 drive connected to the USB Port and the SD card plugs into the SD card reader slot in the device.

 

The device still allowed USB 3.0 transfer speeds and 12GB of files transferred in 6 minutes 29 seconds.

 

As with the previous unit the whole project is run by the “files” app on the Android smartphone.

 

The app allows for a wide range of options from whole drive to individual file transfer.

 

The drive doesn’t support an external power supply to power the drive however the USB-C port is designed to supply up to 2A.

 

Gimbal Landscape Matrix Photography

To get images in panorama landscape photography, which have close to foreground objects, that will "stitch together" without any alignment issues the camera needs to be set up carefully to ensure that there is no shift in parallax as the camera is rotated around the scene.

To achieve this it is usual to use a "gimbal" to allow the camera to be mounted on a tripod so that the lens "nodal point" remains in the same place as the camera is rotated. Panoramic photography gear is ONLY needed when the scene contains close foreground objects. When you photograph from a high vantage point / overlook or a point where the nearest foreground object is located towards infinity focus, you do not have any concerns with parallax. So you could easily make a large panorama without any special equipment.

Many of the gimbals that allow adjustment of the camera in all axis can run into several hundreds of pounds so it is a very expensive option if you only shoot a few of this type of image. Often, I use the panorama format simply because the spaces above and below my subject would boring with a 2×3 aspect ratio. Panoramas are not ideal for every composition, but they are crucial tools in more situations than you may think.

When you construct large matrix landscape images there is a “hidden benefit” is that I can extract ordinary 2×3 photographs from this massive panorama, and the large number of pixels means that I don’t sacrifice image quality along the way. 

Look at this large matrix panorama The M4/3 image is 12808 x 6765 made from 15 individual images (5x3)

This is an extracted image from the above panorama showing the amount of detail that is within this image. By comparison this is the same panorama shot with the iPhone X with the 58mm EFL lens,

This the same extracted image from the above image which shows remarkable levels of detail and is more than sufficient for use in screen images, social media web pages etc. It would not allow large format prints due to the lower number of pixels (1700 compared to 1300)

 

 

 

 

 

 

This is a typical "gimbal" sold for 360 degree panorama photography.

It is technically poor as it does not offer complete adjustment of the nodal or "no parallax" point of the lens. It only allows the vertical positioning of the camera but not front to back or side to side.

Whilst this is better than hand held it is not a perfect solution to the problem.

 

.....to be continued.

Modifying the Godox AD-L to be a Standalone Light Panel

The AD-L is a 60 LED matrix light designed to attach to the AD200 flash unit from Godox. It adds a little extra functionality to that unit.

I like to maximise the use that I get from all my accessories and spotted the opportunity to make this unit into a light panel that could be powered from a 8.4v lithium Ion cell or a USB power bank with the addition of a 5v to 9v dc-dc converter.

 

This LED unit has a slightly higher output compared to the Godox 64 LED light unit ( about 2/10 F-stop) but has a more neutral characteristic where the output from the ^$ led unit has a slight green appearance.

The completed light mounted using a smartphone clamp on the Manfrotto Pixi tripod.
The completed light mounted using a smartphone clamp on the Manfrotto Pixi tripod.
The unit being powered via the USB power bank and the 5v to 9v step up converter.
The unit being powered via the USB power bank and the 5v to 9v step up converter.
The pre-wired female 5.5 x2.1 connector and the Dupont contacts soldered onto the cable.
The pre-wired female 5.5 x2.1 connector and the Dupont contacts soldered onto the cable.

The necessary cable to supply power to the unit was made up from a 5.5mm x 2.1 mm female socket that was pre-wired 

 

The actual connector to fit the pins on the AD-L are standard 2.54mm/0.1 inch Dupont type connectors.

 

To improve the mechanical strength of the cable to connector I used some heat shrink sleeving to fasten the cable to the connector shell.

 

The contacts for the Dupont shell were soldered onto the cable of the wired socket. I manually crimped the contacts to make them fit inside the shell as I don't have the correct crimping tool for the small contact size.

 

 

 

 

 

 

 

 

The first layer of heat shrink applied to strengthen the connection.

 

with the socket oriented with the latching lugs facing upwards the 9v wire (red is the first contact and the 0V ground is pin 2 black)

 

 

 

 

 

 

 

Another layer of heat shrink to strengthen to mechanical properties of the plug.

 

 

 

 

 

 

 

This is where the connector plugs onto the pins of the AD-L connector.

The first pin is the +9v wire and the second pin is the 0v ground wire.

In my final version I wired a 4 pin Dupont shell to add some extra grip to the connection and labelled one side top to denote the correct orientation.

The unit can be powered by a 8.4v lithium ion battery such as the Sony NP-F type in a battery tray with the 5.5 x 2.1mm socket. The current taken by the light is around 400mA at 9v. Alternatively using a USB to 9v dc-dc converter the unit can be powered from a USB power bank.

 

 

Ready Made Lead

 

 

 

 

I have a number of the leads made up now for the Dupont to 5.5nn x 2.1 mm female socket.

 

 

You can purchase these from my on line store

here

Synch Speeds with Panasonic Bridge and CSC Cameras

 

You are probably aware of the expression used to enable cameras to record flash images when the shutter speed is higher than the fastest synchronisation speed of the camera (normally 1/250 -1/320 sec)and this is HSS or High Speed Synchronisation.

Now this ONLY applies to those cameras which have "curtain shutter: such as in the CSC (compact system camera) or DSLR.

With these cameras the way that the exposure works is as follows:

Basically, at high shutter speeds the rear curtain starts to close before the front curtain fully opens. This way only a slight gap between the two blades as the exposure moves across the image sensor. It is within this moving gap of exposure that the flash fires in a series of reduced power light bursts. It requires a specially purposed flash gun that can do this. Even so the flash cannot be used at full power.

Typically the flash may be reduced to 1/4 power to enble the flash to fully recharge for each consecutive flash burst

 

The flash does fire longer than in standard flash mode to illuminate the whole of the image formed on the sensor. In standard flash mode, the flash duration is much shorter than the time it takes for the shutter to move across the image sensor, and the partially opened shutter will cover part of the frame. This would leave large sections of black in your image.

 

What it does is it emulates a constant light source...and just like any other constant light source, but it does not stop motion.

As far as how long the flash duration actually is, it's very fast, but it strobes on and off rapidly during the entire travel of the shutter...so that as far as your camera's sensor was concerned it was one constant light source on the whole time.

 

 

 

 

 

 

 

A close up of the first and second curtains set for a high shutter speed and hence the narrow gap between the curtains.

It is through this gap that the pulsed flash fires to expose the sensor as a band of exposures.

In contrast the "Bridge Camera" doesn't have a first and second curtain shutter. Instead it has a "Leaf" shutter which is actually in the lens.

As this leaf shutter has a smaller mass than the two curtains it can open and close extremely fast (up to 1/4000 second)

With this type of shutter there is no "synchronisation" issues as the camera can take flash pictures all the way to this maximum value.

When using the pop up flash or a flash unit mounted on the hot shoe this is true, however if you use an optical or wireless slave to fire an "off-camera" flash unit then you will find the the "propagation" delay will affect the maximum speed that the camera came take the images without the image being affected.

This propagation delay is caused by the camera having to trigger the master unit through the hot shoe generating the radio firing signal which is then received by the salve unit when then converts this to the firing pulse to fire the slaved flash.

The slave flash now has to ignite the xenon tube. This delay causes the flash to fire midway bring the exposure and thus the light from the flash is being clipped.

In my tests with different types of radio transceivers I found that I was only able to shoot up to shutter speeds of 1/1000 second. Faster than this and the image became progressively darker as the speed increased.

 

The solution to this is to connect the remote flashgun via an extension TTL cable or using a PC flash cable with a hot shoe adaptor on the camera and the base of the remote flash unit. This way there is no delay and the maximum shutter speed can be used.

 

 

 

 

 

 

 

 

The way to increase off camera flash maximum synch speed by using a wired cord

This can either be a TTL extension cable or use PC hot shoe adaptors and then connect the camera and flash with a male to male PC cable.

Using this overcomes the wireless RF and optical propagation delays

Back Up Camera Power Supply (Proof of Concept Model)

When recording long video sequences, animation or time lapse the last thing you need is the battery to suddenly shut down the camera as it becomes fully depleted. The use of an external power bank and step up converter to give 8.4v is a great solution provided that the power bank has enough capacity for the expected duration of the filming. I thought of a "hot-swap" power supply whereby the power bank would primarily be providing the main power to the step up convertor to give the 8.4volts but also would provide a floating charge to an inbuilt 1200mAH li-ion battery in the unit. Thus when the power bank becomes depleted the internal li-ion battery would then be providing a continuous 8.4volt to the camera. The depleted power bank could then be replaced during this period. One plugged in to the on-board step up converter the 9v provides 8.4v by means of a series connected silicon diode which typically drops around 0.6v. The 8.4volt the "tops" up the li-ion battery (the internal charge circuit will limit the current and than allow the battery to float) and continues to power the camera.

So far the solution has worked without any problems and I will be building it into a suitable project box to ruggedize it.

Below is the basic schematic and the proof of concept board.

 

The proof of concept showing the 5v to 9v (adjusted to 9v) the series diode, back up li-ion battery and indicator LED's
The proof of concept showing the 5v to 9v (adjusted to 9v) the series diode, back up li-ion battery and indicator LED's
the completed project running the FZ2000 camera from a 10,000 mAH USB power bank.
the completed project running the FZ2000 camera from a 10,000 mAH USB power bank.

A New Style Battery Box From Some Amazon Retailers

I am indebted to Ernie Smith of the USA who alerted me to a different type of dummy battery box that he had received. This new type appears to accommodate both the bottom and side entry camera cable inputs.
Ernie machined out a hole in the side of the dummy battery box to establish what the pcb was like as it didn't appear to want to split as with the method (detailed lower on this page) I had described for the older style dummy battery box.

 

This is the hole machined out of the side wall of the new battery box with the new 10K resistor fitted.

To solder the resistor in place was quite as challenge:-

quote Ernie ; after I finally got the “T” pad tinned I measured the distance between the PCB connections, then I shortened the resistor leads, bent them 90 degrees and

then 90 degrees again away from the resistor body. That made a “foot” that was parallel to the PCB. I tined the resistor wires. Then holding the resistor body with some surgical clamps
I managed to get the resistor soldered to the “T” pad. I did it this way because from experience I know that most likely when one tries to add another wire to the same connection, one
of the wires will go everywhere except where is should be. Now you need another hand or two! Once the resistor was attached to the “T” pad is was easy to put the other wire foot
over the black wire, thus holding it in place while soldering everything together. The trick was to apply enough solder to the pad & resistor wires, no added solder needed.

 

here is the dimensions to cut out the hole in the side wall.

 

 

 

 

 

 

 

The positioning of the 10K resistor within the battery box/pcb

After milling out a slight rebate to the hole Ernie then infilled the hole with a piece of plastic card.

 

 

 

 

This is the interior of the new battery box which I managed to split by applying quite a bit of force to separate the two "wings" of the box. This fractured the ultrasonic welded seams.

 

 

 

 

 

 

This is the pad to which the 10K 1/8th watt resistor should soldered between it and the black lead pad.

Battery Eliminator for Olympus OMD Cameras using the BLN-1 Lithium Ion Battery

There doesn't appear to be a commercial dummy battery box for the BLN-1 battery used in Olympus cameras like the OMD-EM5 II so I made my own by de-constructing a third party (DTSE) battery and using a USB to DC-DC converter set to give an output of 7.6V

 

 

This is the completed battery box with the connecting cable installed onto the PCB of the battery. The lithium ion battery has been removed.

 

Carefully split the battery case using a sharp knife and then lift out the cells.

 

One at a time cut the three connections to the cells (don't cut the two + and - wires together as you will cause a dead short on the battery - it might not end well!)

 

 

This is the pcb where you will make the positive (red) and negative (black) connections to the indicated points on the PCB

 

Drill a small hole in the base of one of the battery shell halves to allow the cable to pass through. A suitable cable and female socket should be used.

 

 

Whilst it is not possible to close the battery door if you are using this on a tripod then an "Arca" plate will probably allow tripod mounting and the battery door open vertically.

 

With the USB dc-dc converter set at 7.6v the green battery full indicator shows on the LCD screen

 

 

 

 

As the voltage is reduced the red battery low warning icon appears at 6.93 volts

 

As only two wires are needed with no additional electronics this is an easy modification and any dc-dc  boost converter capable of about 1A output will be sufficient

Adding Battery Level Indication to Panasonic Dummy Battery Boxes DCC8 and DCC12

 

For GH3/4/5 using the BLF19 battery andFZ200/300/330/1000/2000/2500 GX series and some G series cameras using the BLC12 battery.
Most of the generic dummy battery boxes are supplies with AC wall adaptors outputting 8.4v. This voltage is sufficient for the camera to operate however it does not give an on-screen indication of the voltage and moreover it limits the use of the battery box to power solutions like USB to 9v converters etc. If standard lithium ion batteries are connected at a full charge status of 8.4v then the camera will shutdown at about 7.2/7.3volts thus you are not getting the full charge potential of the cell. In this video I show you how to modify the DCC8 and the DCC12 battery boxes used in the FZ/GX and GH3/3/5 series of cameras.
I show how a standard 2S lithium ion battery can then be used to provide full capacity to the camera. Additionally if you use a SB power bank and a DC-DC converter solution you can drop its output to 6.5volts. This means that the power input to boost the 5v to 6.5v is far less than if the converter had to boost it to 8.4v. The converter is more efficient, runs cooler and you will get more run time from the power bank.

 

 

 

 

 

 

 

 

 

The DCC12 battery box used to replace the BLF19 battery

 

 

 

 

 

 

 

The case can easily be opened by inserting a sharp knife blade at each of the four corners and gently prising the seams apart

 

 

 

The modification consists of soldering a 10K resistor (brown, black, black, red colour code) between the -ve terminal and the "T" terminal. Use a small 1/8 watt device.

 

Once soldered the case can be re-assembled with a dab of super glue to secure it again.

For the DCC8 box the soldering is a little more delicate but achievable with care and a small tipped soldering iron. 

 

 

 

 

 

 

 

The generic DCC8 dummy box used with many mains converter solutions

 

Again the case can be opened with a sharp knife blade inserted at each corner and gently prising the seams apart

 

 

The pcb used is probably from a battery manufacturer and merely provides connection to the + and - terminals.

 

Remove the PCB by lifting off the hot melt glue.

 

 

The connection to the "T" terminal is at the third pad from the bottom left hand side.

 

 

Apply some solder to tin this connection before attaching the 10K resistor between this pad and the Black lead on the -ve terminal

 

 

Here the 10k resistor is soldered between the pad and the -ve terminal.

 

Re-assemble and glue the case again using super glue.

 

USB POWER BANK POWERED CAMERAS AND THEIR FAILURES

I've been spending a lot of time investigating and building my own USB power bank dc-dc converter to power Panasonic cameras.

I have found that most of the commercial units are good for 1Amp intermittent operation and are thus suited to video recording or continuous shooting with the electronic shutter selected. If you select the manual shutter and burst mode the power bank & converter cannot keep up with the demands made upon them and the camera often resets or freezes - the only way out is to remove the USB power lead at this point.

This then begs the question whether there is such a solution to this current demand. The FZ1000 seems to be OK but the FZ2000/2500 suffers this problem.

Modifying the Output From 9v Power banks and Convertor Cables to the Safe 8.4v Limit

If you are running your Panasonic camera (or any other DSLR/Mirror-less camera) which was designed for using the 7.2volt lithium ion battery and using a dummy battery box with a 9v power supply then you may be overstressing the camera and may cause premature failure of the camera power supply.

Some 9v power supplies have a tolerance in the specification of 1 volt so you could in fact have a power supply which is nearer 10volts than 9volts thus stressing the camera even more so. There is likely to be a slight voltage drop to the camera by the very nature of the connecting cable and connectors and this may be in the order or 0.5 volts depending upon the load taken by the camera. When the camera is idle the current drawn is only about 300mA so the volt drop on the cable is low so the higher voltage will appear at the camera dummy battery terminals.

A safer way is to use the forward voltage drop of a silicon diode to drop the voltage by about 0.6volts without any current compromise.

 

 

 

 

Here's how to construct a suitable connection socket and plug to achieve this. The diode a  GP150 (general purpose 1.5A diode or use a 1N54 series diode) connected in series between the input and output. The cathode (ringed end of the diode) goes to the output

 

Here's the completed unit with a couple of plug shells over the connectors to add mechanical strength.

 

A better idea if you cannot solder this small component pack is to build the diode and a 104pF capacitor and a 100uF 10v capacitor into a box. The output of the diode is connected to the 104pF and the 100uF capacitor to a common ground.

 

This capacitor network helps to smooth out some of the switch mode power supply "noise" making the input to the camera both safer and cleaner.

Such a project is shown below.

 

 

 

 

 

Here the unit uses the same 5.5mm x 2.1mm input and output but it could be fitted with the 4mm x 1.7mm plug and cable for Panasonic DCC coupler units.

Modifying the Qutaway 5v to 9v Conversion cable for 8.4 Volts

 

This is the pcb from the Qutaway product. The case is easily removed by inserting a sharp blade at each corner and prising the two halve apart.

 

on the left is the input from the USB plug and on the right the output cable.

 

We are going to add a series diode in the red output lead to drop the 9v to 8.4v as shown below.

 

Note that the adaptor featured here will support video recording or burst mode with electronic shutter and single mode shooting with the mechanical shutter operative otherwise the camera demands too much current and resets when used with the FZ2000/2500, on the FZ1000 it is OK.

Here you can see the addition of the GP150 silicon diode (or a 1n54 series diode) connected in series with the red lead.

 

De-solder the red lead from the pcb, insert the diode with the anode (plain end marking) to the pcb and then connect the red cable to the cathode (ringed end) of the diode.

Ensure the diode is clear of the pcb when installed.

Re-fix the covers and add suitable marking to the unit to designate it now to be 8.4 volt output.

 

The completed unit.

 

Amazon link for module

 

Amazon UK http://amzn.to/2w34ZW5

Amazon USA http://amzn.to/2u1w52s

 

 

 

8.4v battery replacement for Panasonic cameras

 

 

 

The FZ2000/2500 being powered by a modified 5v USB to 9v dc converter unit (amazon UK http://amzn.to/2w6Oibi    amazon USA http://amzn.to/2eTt11G  amazon Canada  http://amzn.to/2v4iFCw)

 

Note that the adaptor featured here will support video recording or burst mode with electronic shutter and single mode shooting with the mechanical shutter operative otherwise the camera demands too much current and resets when used on the FZ2000/2500 camera. It appears to be OK on the FZ200/300/330 and FZ1000.

 

 

These units provide a well regulated 9v output however with the addition of a series 1N series diode like the IN4007/1N4001 the voltage will be reduced by up to 1v bringing it within the safety voltage limits of the camera

 

 

By opening the plastic shell using a thin knife blade inserted at each corner of the unit and then de-soldering the red output lead and inserting and soldering in the diode with the cathode (ringed end) facing the red wire the unit will perform reliably from a power bank with a genuine 2A output port,

Generally these are fitted to the higher capacity units.

 

If the power bank cannot provide a continuous current of 2A then the camera may not power up, shut down on zoom or recording video)

 

With the diode in place the unit can deliver the 8.4 volts needed by the camera (7.9 volt lower limit).

It has a conversion efficiency of around 75% in my full load tests.

 

Depending upon the camera model the 8000mAH power banks should last for about 10-12 hours for the FZ200/300/330 and 6-8 hours on the FZ1000/2000/2500

 

 

 

 

 

To connect to the DM -DCC8 dummy battery you will need to adapt the 2.5mm male plug by use of the  4.0mmx1.7mm Male to 5.5mmx2.5mm Female Jack DC Power Connector shown opposite 

 

                                  

USB Power bank 8.4v convertor for Panasonic Cameras.
After a lot of testing different dc-dc boost converters that are commercially available I have now chose the board that will be used in this project.
These boost modules typically can change the input voltage by a factor of up to 10 times. In theory that sounds fantastic, in practice however, the story is a little less so and here's why!
These units work by the same principal that the ignition coil in your car works. If you "break" an inductive circuit you get a very high voltage appearing across it. This is harnessed in these converters by using a high efficiency diode to charge a small capacitor. As this switching occurs at a frequency of about 400KHz the output appears almost as thought it was DC voltage as the diode/capacitor smooth this out.
The "efficiency" of these units in converting the low voltage to a higher one varies considerably from make to make depending upon the components used in the design. Some are more efficient when providing lower voltage step ups such as 3.2v to 5 volts as used in lithium ion battery power banks than at higher voltages.
Typically the Panasonic cameras have a quiescent current of about 250-350mA just powering the OIS and the LCD screen and when the camera is set to a zoom operation it can rise to 850 mA. Typical power on surge when the camera is first turned on can be in the order of 1.25A.
So my little converter has to be able to cope with these power demands and have a high enough efficiency in converting the power bank USB output of 5v to 8.4v.
The first converter that I thought was going to be ideal (based upon the spec sheets for it) turned out to be very inefficient at these low voltages. Typical modules ( I tested a batch of 5 of each type) gave a conversion rate of 1.3A drawn from the  USB to provide 500mA at 8.4V.
So that is 6.5Watts input for 4.1Watts output which is just 63% efficient. The module ran quite warm.
I did test a unit which ran at 93% efficient however it was five times the price so in a cost/benefit calculation I decided against this unit.
The one I chose for the final design gave 4.9Watts input for the same 4.1Watt load which is 84% efficient and the module was a lot cooler when tested over a 24hour soak test.
In reality either module could have been used however the higher efficiency one would give longer run times from the USB power bank.
I have built the unit into a small battery case and added some extra over voltage protection to the output. The actual "chip" on this particular unit provides a soft start to prevent overshoot of output voltage, over current and thermal protection I added the "belt and braces" over voltage to prevent the unit delivering too high a voltage to the camera that it is attached to.
This unit will connect to the DMW-DCC8 for the FGZ200/300/330/1000/2000/2500/G series and all other cameras which use the BLC12e lithium ion battery. With other dummy battery boxes it can power other cameras such as the DMW-DCC7 for the GH3 or Canon/Olympus cameras with the right dummy battery. You can of course also use a wall outlet USB charger providing it has a rating of 2A so you don't need to take the larger, heavier mains power supply with you an a trip.

These dummy batteries are readily available with AC power adaptors from Amazon for as little as £12 in the UK
http://amzn.to/2uUn6Qz

or $18 on Amazon USA
http://amzn.to/2tAPqqP

no need to buy the Panasonic DMW-ACC8 box at three times the price!
(this adaptor  #3892A300 I have disassembled  three units now to verify compliance to good design principals such as track separation between input and output, component choice, protection devices and general soldering technique and then carried out a 24 hour full 2A load reliability test).
So with the mains power unit you have the benefit of continuous power in the home/studio and can then use the DMW-ACC8 battery box along with my USB to 8.4 v adaptor and a power bank, outdoors.

 

 

 

 

 

 

 

The components for a USB powered Panasonic camera using the DCC8 dummy battery box from the ACC8 power supply.

Range Extender for Panasonic Remote App

The range of a Wi-Fi connected camera to a smart phone/tablet appears to be about 10 metres (30 feet). Whilst this may be adequate for most users sometimes you want to control the camera over greater distances. I had the idea to use and old router as a Wi-Fi-extender to allow these greater distances. The router I chose was an old D-Link which was mains powered through a 9v dc power adaptor. To allow this to be used away from the house I used a USB to 9v adaptor (from Amazon - it also supports 12volts at 2A) and a 8000mAh power bank.

You begin by connecting the camera to the router via the camera Wi-Fi menu selection By Network option.

When the list of Wi-Fi devices is shown, chose your router and enter the router password from the camera screen.

You can now open the Panasonic app on the smartphone/tablet and connect to the router to establish the connection to the camera.

The router will give an additional distance (100 feet) 30 metres so if the router is placed within the 10 metres of the camera the smartphone/tablet can be up to the 30 metres point giving 40 metres in total.

 

USB adaptor - Amazon UK http://amzn.to/2uoldv0

USB adaptor - Amazon USA http://amzn.to/2sVxfaV

Schematic for the working version of the AGC Defeat Unit

 

The final circuit turned out to be more simplistic than I had originally thought.

I assumed that the input would need to be a sine wave to prevent harmonic distortion if a square or triangular wave was used for the input to the camera. In testing I found that the camera would still perform well with a square wave input so I decide to try both an astable multi-vibrator pair of transistors running at 20 KHz and a NE555 timer IC.

In the end I decide to use the more stable 555 IC as the frequency remained solid even during the battery run down.

Here is the schematic for the project.

The timing is done by R2-C2 giving 20KHz. The output from pin 3 is attenuated by R1-R3  to 7-8millivolts at the camera input after being coupled with the mic input and allowing for its impedance.

the right hand mic input goes straight to the camera input whilst the left hand input has the 20KHz signal injected into it.

If you wanted to get finer control of the AGC defeat voltage  input R3 could be substituted with a 27K resistor and a 100K potentiometer in parallel with it. The output would be taken to C3 form the wiper of the pot. This would allow the output to be set for 0V to about 10millivolts.

The unit is powered by a PP3 9v battery.

Here is the built unit. I used a stereo splitter cable from £/$ store to get the wired 3.5mm inline socket. The 2.5mm plug I wired but again it could be obtained from a 2.5mm to 3.5mm audio cable if you didn't want to have to solder one up.

The version 2 of this unit now features a trim pot (22K) in place of R3 ( the wiper connects to C3) so that you can adjust the level of the bias signal sent to the FZ200. Adjust to about 1/3 or the rotation as a starting point. Do a test recording with the unit on and adjust the trim pot until the background noise doesn't increase when you stop talking.

AGC Control for Panasonic Lumix FZ200

This is work in progress to produce a small device which will defeat the automatic gain control (AGC) of the FZ200 camera when using external microphones.

The AGC is responsible for keeping the audio recording levels at a point which is audible but not clipping causing distortion.

In most situations where the audio is constant this circuit performs well. However, in other situations like interviews, music recording and dictation there may be brief periods where there is no audio input. During this period the camera AGC will attempt to raise the background noise from the mic or its own pre-amp circuits to the normal level. You can here this as random hiss noise on the recorded audio track. As soon as the audio breaks this silence the camera AGC has to then quickly turn down the gain to get the audio back under control. The first second of this might be distorted as the AGC has a hysteresis lag.

I have been working on a small unit which will be battery powered and will allow you to plug an external stereo mic into it and then this unit plugs into the 2.5mm mic input socket of the camera.

In operation this unit generates an inaudible 20KHz signal of about 6-8 millivolts and is combined with the left hand channel of the audio. As this waveform is what the camera would expect to see for average recording at the right level no change in the AGC is made if the input volume decreases. It will still control the passages which exceed this recording waveform. As it is over the normal threshold for hearing the audio track does not contain this and cannot be heard.

The initial proof of concept uses a commercial waveform generator IC however my final design will be a much smaller unit using smaller and discrete electronic components. Here is the proof of concept at the moment

 

Here is the test of the unit in the proof of concept stage.

 

I now have a prototype of the simplified version and her is the video test

Studio Flash Equipment for Amateurs

whilst not everybody needs to invest in studio grade flash equipment  I thought that I would share my experience in trying to put together a simple, cost effective system that I could use for general photography in my small studio space. For most purposes I can use speedlites with a guide number of 50 metres or more at ISO 100 and trigger then either optically, or increasingly these days using wireless triggers. Larger, more powerful flash heads give more creative possibilities but I didn't want to have to spend lots of money on something that doesn't get a lot of use.

I settled for the Godox systems using the AD200 (200 watt second) and the AD600 (600 watt second units).

 

The AD200 is quite a remarkable, dual flash head, system. It has a conventional xenon fresnel lens speedlite head with a guide number of 52 and it also has a bare bulb flash head with a guide number of 62. The bare bulb head can be modified with any number of reflectors and, if mounted in the Bowens type adaptor plate (as seen in the top illustration) can be used with an even more extensive range of flash modifiers.

The AD200, at a push, can be hand help and triggered by an on-camera Godox "X" series transmitter (Canon,Nikon or Sony) however it is quite a heavy (0.5Kg)unit despite being only the size of a regular speedlite. It is lithium-ion powered and recycles in just 2 seconds from a full power discharge

The AD600 is just a bare bulb unit with LED modelling light. again lithium-ion powered and recycles in just 2.5 seconds from a full power flash discharge. It is too heavy to hand hold and is supplied with a handle which can be fitted to a conventional lighting stand.

Both units have a 3.5mm sync port so they can be used with any remote cable triggering device and support the S1 and S2 optical trigger modes for instantaneous and pre-flash suppression modes.

Wireless Flash Trigger Systems

wireless trigger systems have evolved to quite an advanced level now. It is possible to get systems which will transmit the TTL data from the camera to the flash enabling full TTL control without the need for extension cables from the hot shoe to the flash unit. The Godox "X" system is such an example of this implementation. It is currently only available for Canon, Nikon and Sony flash systems to enable full TTL control. It can however be used to trigger manual flash guns and also act as a remote shutter release as well.

remote shutter operation on Panasonic FZ300/330
remote shutter operation on Panasonic FZ300/330

Wireless triggers have a superior performance over optical (line of sight) devices. They have a range of up to 80 metres or so outdoors and can pass through solid walls and floors making them ideal for situations where the camera and flash are in different locations or out of line of sight.

With the Godox "X" system normally a dedicated transmitter and receiver pair are used to link the host camera and the flash unit. It can, however be used to provide centre pin firing on nearly all flash units which have the capability of being able to be set up in a manual power mode. In the example above the Canon system transmitter pair are firing the Nikon flash unit. The camera can be any camera capable of triggering via the centre electrode.

Audio Equipment For Videographers

 

Getting good audio quality for your video productions is almost, if not equal to, getting the right lighting and exposure!

Viewers may be tolerant of out of focus or badly lit shots but poor audio quality is likely to be a big turn off.

 

It needn't cost a fortune to improve the audio quality of your productions and in this section I will introduce you to a few ideas that might help you do this.

 

 

The biggest improvement that you can make is to use an external microphone. The internal mics are omnidirectional and pick up sound sources all around the camera. Handling noises, the image stabiliser whirring in the lens barrel and generally they are too far away from the subject in an interview type situation. They are good for providing a perfectly synched audio track from another external recording source such as a portable audio recorder.

 

The external mic ideally should be "off-camera" and close to the sound source however even a directional "on-camera" mic can make a vast difference to your sound production.

 

Let's begin by looking at the cheapest option and one, which surprisingly, gives really good audio quality for interviews, voice overs and commentaries etc.

 

A simple £3 ($) electret condenser lavaliere (tie clip) mic can be plugged directly into the mic port of the FZ300/330/1000/2000 or with a 3.5 to 2.5mm adaptor into the FZ200.

 

They usually come with just a couple of metres (6 feet) or so of cable so it might be necessary to add a 3.5mm extension cable to allow you to rig the mic without danger of pulling over the camera!

I have used over 6 metres (20 feet) of cable without any noise/hum pick up. 

When positioned about 20cms ( 8 inch) from the mouth and clipped to a shirt/blouse/coat etc will give surprisingly good audio. because of the close proximity to the sound source the mic level can be turned down in the camera and this will help to reduce other ambient noises.

 

The mics are omni-directional so will pick up sound from all directions. You can mount the mic with the front port facing down and this will help prevent "popping" noises on some syllables.

 

A step up in quality is the use of a self powered electret condenser mic such as the one shown opposite - the Audio Technica ATR3350

(or the Boya mic http://amzn.to/2mHAdPZ) £16 ($).

This mic has its own inbuilt silver oxide battery which lasts for ages and has abot 6 metres (20 feet) of cable terminating in a 3.5mm (1/8 inch) plug. 

 

It will work directly with cameras with the 3.5mm mic port or via a 3.5mm to 2.5mm adaptor on the FZ200.

 

 

Sound quality is excellent with very little electrical noise. Again the mic level can be reduced to help with ambient noise reduction. 

 

 

 

 

If you are worried about the possibility of walking away from the camera whilst still attached via the lavaliere mic (yes it does happen)

then the next alternative would be a "wireless system" like the one opposite. Its a UHF system so wireless interference is very much reduced. The range is over 80 metres (200 feet) outdoors.

 

Again audio quality is excellent and it gives you a lot more freedom during your presentations etc.

 

For isolating unwanted sound a "rifle" mic is often recommended such as the one shown opposite the Boya BY PVM1000

This is a self powered (single AA alkaline battery) electret condenser microphone with XLR (and phantom 48v power) connection.

 

Although this isn't the ideal location for this type of microphone it is better than the internal mics.

 

The ideal placement for such a mic is directly overhead the subject with the mic pointing down.

The front lobe pickup from the mic then picks up the voice whilst the super cardioid pickup pattern (where the side of the mic are largely insensitive to external sound) help to reduce any other ambient sounds

 

For videos or podcasts where the mic being in view doesn't really matter then the studio condenser mic is a good choice. The BM-800 is only about £23 ($) and comes with its own shock mount system. Some suppliers also offer table stands or full mic stands to support the mic.

It can be powered from the camera by the slight bias voltage which appears at the mic input port but best operation is attained by using a phantom powered pre-amp system.

 

Again because of the close proximity to the speakers mouth the sound is rich an d golden and again ambient noise is reduced by being able to reduce the mic input gain level.

Above is one of my recording setups for use with the FZ2000 but it could be used on any camera system.

A BM-800 studio mic, the ATR 3350 lavaliere mic, the Saramonic smart rig+ for the phantom power and mic pre-amp and a pair of headphones for audio monitoring.

An alternative system utilising the Boya BY-PVM1000 rifle mic and the Saramonic SR-AX100 power supply/pre-amp unit.

  • Two-channel active audio mixer with pre-amplifier and phantom power
  • Accepts signals from a wide variety of mic or line level sources such as balanced xlr microphones, 3.5mm microphones, wireless microphones and external audio mixers.
  • Attaches to the base of the camera and there is a threaded socket on the mixer base that allows for mounting on a tripod or case

LED Light Panels - Looking at what they exactly offer the stills or videographer.

 

I think we can all agree that natural daylight is probably the best light source we can use to create our images and video clips. Even in harsh sunlight we can employ techniques to tame it into the quality that we might need for a particular photoshoot. The use of reflectors and diffusers are some of the techniques that I have previously covered to show how to do this - particularly when photographing flowers as too much contrast kills the delicate tonal shades and destroys the very fine detail that we can see in petals etc.

But what about indoors when sunlight is not available such as after darkness fall?

Traditionally this was the place that tungsten lighting was employed. Photoflood bulbs and reflector lamps were the key components and I can  still remember many a burned finger trying to adjust the position of these lights!

but today with advancement in LED lighting more and more studios are converting to LED light panels if they do not shoot with studio flash equipment. Running costs are more lower, the heat generated is far less and some can be self powered meaning there is less likelihood of trip hazards from trailing power cables.

 

 

This is a typical 10 x 12 inch LED light panel from Yongnuo.

It has 600 LED's and can be adjusted fro 0 to 100% brightness in fine incremental steps.

 

At first you would imagine that the light output from these large panels would be adequate for both stills and videography as they do look very bright when turned on and set to maximum intensity.

In reality the light output is actually quite low and two or three lights may be needed, especially for video work where we need to use shutter speeds of around 1/60 second. For commercial work where the subjects are static then long exposure times can be used. However for portraiture type work large apertures may be required, or higher ISO settings, in order to make these work in this situation.

 

Apart from light intensity there are two other factors which must be considered when choosing and using these lights; colour temperature and colour rendering index (CRI).

 

Having just acquired a new app for my smartphone it makes it very easy to measure colour temperature now rather than having to shoot an image and look at it photoshop or lightroom

It was these two later parameters that I wanted to investigate more so I did a series of tests on the LED lights that I most frequently use and which are still generally available for sale on Amazon or Ebay.

To do the tests I used the Canon 5D mark 3 as Canon digital colour science, in my opinion, is extremely good.

I shot a series of test images using a 18% grey white balance card and a colour checker patch in daylight and with each of the LED's. I kept the LED's at exactly 1 metre from the subject to that I could get a comparative Light Level reading in LUX and translate this into exposure times at f5.6 and ISO 100.

 

 

This is a typical image from the test series:

 

Using the camera in AWB (auto white balance) enabled me to also see the range of automatic adjustment made by the camera in each colour temperature situation.

 

The meter shows the measure light level in Lux (x10) and I have indicated the camera exposure to give the correct exposure for the gray card. The colour patches show any variation in light output in terms of RGB as traditionally low CRI LED's may have green spikes or low red outputs.

 

here is the full gallery of the test images.

This is the Aputure AL-528W by Amaran:

It measured 5200K, so pretty close to daylight and produced 3000 lux at 1 metre with the diffuser fitted. Without it there is a slight noticeable fall off in this image set but the light increased to 4460 lux giving 1/3 stop extra light.

When the 3200K CTO filter that is supplied was fitted the light level dropped dramatically to just under 1000 lux and just over 1 f-stop needed to correct the exposure. Note how this shift was not accurately corrected by the Canon 5D mk3 - quite a surprise! it took a further adjustment in adobe photoshop to render the gray card correctly as seen in the last image.

This is the MCOPLUS LE-520B, soon to be replaced by two more powerful units.

I note I have made a mistake in labelling the lux output - it should be 780 and700 Lux, not 7800 and 7000 in images 1 and 3!

This is a two bank LED system, one bank made from 3200K LED's and the other one 5500K. This obviously drops the power output as only half the lights are on (unless you switch both banks on)

the measured colour temperature was slightly warm at 5130K with the 55K bank on but pretty close at 3140k with the 3200K bank on.

Again the %D was not able to correct the white balance and post processing was needed to bring the white balance back to neutral.

Exposure times were down to 1/13 sec to produce the correct exposure at 1 metre distance.

This is the Yongnuo 300 LED panel which is just one colour temperature. Again it measured slightly warm at 5060K in the supposed 5400K daylight mode. Quite a good output from this light although it is more compact and casts stronger shadows as it is more of a pin point light source compared to the larger panels. With the diffuser removed it gave 1/3 f-stop increase in light.

The two remaining lights were the typical small 32 and 64 LED lights sold as hot shoe mounted video lights.

With outputs down at 1/3 second these are really totally unsuited to video work unless the camera is within a few inches of your subject. They hardly produce enough light for fill in if used on camera in bright conditions out doors and at 67K are too cold to try and mix with tungsten light if filming indoors. They can me used as small accent lights in some scenes but not by any means key lighting.

So in summary what have I learned from this testing?

Well it confirmed that the newer light panels are now pretty close to their advertised colour temperatures and don't need colour gelling to get the right temperature. Colour rendering across all the lights now looks perfectly adequate for most amateur lighting use and when a manual white balance in camera is performed should give some very accurate colour reproduction.

What was a total surprise was the fact that the Canon 5D mk3 was unable to apply enough correction in the AWB mode to correct for scenes shot with the CTO orange filter fitted on the fixed temperature lights or with the 3200k LED lights.

 

The final composite is a sample of the LED lights showing the relative outputs, colour temperature and colour rendering