C100: External power, 8.4v vs dummy adapter

Darren Levine

Darren Levine

Veteran
it's always puzzled me why cameras that take 7.2v batteries, have DC jacks that want 8.4v

i've debated and debated getting an all in one battery solution such as a v mount or AB. These types of solutions: http://www.ebay.com/itm/V-Mount-HDM...035?pt=LH_DefaultDomain_0&hash=item416c7dfbd3

such a fantastic idea, but every single one of them missing the magic number of 8.4v

There's then one thing that could bridge the gap: a dummy adapter.

problem: are there seriously no dummy adapters for the can BP style batteries?!

if anyone knows of one, please inform me. i have to imagine it's out there. making a DIY dummy wouldn't be terribly difficult, but it just surprises me that such a thing doesn't exist with a battery that spans so many cameras. i imagine the obvious answer is because all the cameras it's used on have DC jacks.

that, and i've always pined for something of an, in between adapters, a plate that would go between the camera and the battery, with a cable tapped to the 7.2v of the battery. or a third party battery with such a tap. a few products like that exist for sony batteries, but none for these canon ones.
 
Very good point, Darren.

+1

I have a lovely shoulder mount rig I built for my FS100 (now sold) that... I can't believe I'm typing this... I'd like to adapt for my C100.

I ditched my FS100 for the C100 because of the time/money I spent on building a rig that everyone laughed at yet didn't increase picture quality.

I recently did a job in Dubai where my whole plan of being fast moving, discrete and high quality, blew up in my face - they wanted Circus! Matte Boxes! Fluffy Mics! Big Rigs! EVFs! I could have doubled (actually tripled) my day rate just by adding my rig.

So, having got the amazing Hawk-Woods V-lock Power Station, would be interesting to learn how to power a C100 off it.
 
it's a dilemma which i constantly question myself on, for the reason that all it does is allow everything to be powered off a single battery, but in the case of these cameras, how much of a big deal is it really just to have the camera use its own batteries, and still use this power station for other accessories like light, audio, monitor, etc...

the answer i keep conflicting with is that no, it's not a big deal, but when if you've got such a power station, and it's THERE, and the camera's dc jack is THERE, i just know i'd be cursing at the stupidity of not being able to plug them into each other. especially over a difference of 1.2v.

maybe i should contact all the ebay sellers and see if can't get one of the makers to add an 8.4 plug, or probably easier to just get them to make a dummy adapter, or make the dummy adapter myself.
 
There are many great engineers, making custom solutions, fixing things, improving things.

If one were to get a dummy battery, send it to a chap with leather patches on the elbows of his cardigan, organise a very nice single malt to vector its self to the dummy battery, the cost of adding a few capacitors and resistors in a little box with rubber grommets in and out would be a small price to pay for the relief of such a powering system. However, the boss who employs aforementioned engineer may have other issues about how much time it takes to do when interjected with what the engineer is engaged to to, and the above-line cost of having to deal with the impatient queues of videographers and their aggressive emails that follow their orders.

I feel this will be cured over a pint or two near a wonderful workshop, the handing over of a single malt to lubricate the fabrication of custom cables. Just like it was always done in the past. LOL
 
Something that a LOT of people have run into on the C300(myself included) when powering the camera and wireless receiver(on camera ENG style) from the same power source(i.e. A/B plate) is that it introduces a 'ground loop hum/buzz' into the audio(after one of the firmware updates, it actually changed to time code bleed on mine). It's a well know and frustrating issue. You can work around it by powering either the cam or the wireless separately from one another, but then it totally defeats the purpose of putting a single battery power solution on the camera.
 
Darren, I can offer you some insight that might help you with your dilemma. All Li-Ion "DV style" batteries like for your camera put out a range of voltages depending on the state of charge. Fully charged they are about 8.4V, depleted around 6V. While powering a camera they start at 8.4V, spend most of their time around 7.2-7.4V, and end up at around 6V.
The camera does not care as it regulates the voltage down to its own internal reference voltage.
The industry never agreed to any specific label (7.2V, or 7.4V, or 8.4V) so you see all kinds of labels on the jacks and batteries, while the real thing can be anywhere in the range of 6V-8.4V.
There is one exception to that. Some manufacturers intentionally put in software limits to the externally connected power sources to lock the non OEMs out. For example, Panasonic GH2/3/4 cameras want to see only specific voltage around 7.7V coming in, throwing an error message if it is above or below that.
Hope this helps
Darren Levine said:
it's always puzzled me why cameras that take 7.2v batteries, have DC jacks that want 8.4v

i've debated and debated getting an all in one battery solution such as a v mount or AB. These types of solutions: http://www.ebay.com/itm/V-Mount-HDM...035?pt=LH_DefaultDomain_0&hash=item416c7dfbd3

such a fantastic idea, but every single one of them missing the magic number of 8.4v

There's then one thing that could bridge the gap: a dummy adapter.

problem: are there seriously no dummy adapters for the can BP style batteries?!

if anyone knows of one, please inform me. i have to imagine it's out there. making a DIY dummy wouldn't be terribly difficult, but it just surprises me that such a thing doesn't exist with a battery that spans so many cameras. i imagine the obvious answer is because all the cameras it's used on have DC jacks.

that, and i've always pined for something of an, in between adapters, a plate that would go between the camera and the battery, with a cable tapped to the 7.2v of the battery. or a third party battery with such a tap. a few products like that exist for sony batteries, but none for these canon ones.
Click to expand...
 
Run&Gun said:
Something that a LOT of people have run into on the C300(myself included) when powering the camera and wireless receiver(on camera ENG style) from the same power source(i.e. A/B plate) is that it introduces a 'ground loop hum/buzz' into the audio(after one of the firmware updates, it actually changed to time code bleed on mine). It's a well know and frustrating issue. You can work around it by powering either the cam or the wireless separately from one another, but then it totally defeats the purpose of putting a single battery power solution on the camera.
Click to expand...
The problem might be due to the stepdown regulator in the A/B solution that you use. You might be better off using a SWIT S-8845 battery that has a DC power tap jack. The battery puts out native 7.2V voltage, so there is no added noise from a stepdown circuit.
 
I've upgraded a C100 to external battery power recently. I'm UK-based, but I think the same or similar products can be found in the USA.

Matt, the Hawk Woods power distributor can be interfaced with the C100 DC input with one of these:

http://cvp.com/index.php?t=product/hawk-woods_lr-09

If you have an Atomos, it powers up with one of these:

http://cvp.com/index.php?t=product/hawk-woods_lr-05

Re the audio ground loop - removing the ground on pin 1 (Hawk Woods recommendation) has had no detrimental effect on our Micron radio mic receiver - although it does come out at line level, when using external power. YMMV with mic level signals.

Some pics (repeated from elsewhere, but perhaps useful here in this different context):

Matobo SWIT 02.jpgMatobo SWIT 01.jpg

Ben.
 
Thanks for the information Alex. This problem has gone to Abel Cine and Canon both(by many people) and to my knowledge, the problem hasn't been fixed. I could understand(not forgive) the ground loop "hum/buzz" when everything was connected together(A/B plate powering C300 via DC jack, power tap cable powering Lectro SRb and SRb connected via XLR's to C300), BUT the really strange part was after one of the firmware updates the buzz/hum became TIMECODE BLEED.

I really like the image my C300 makes and it is used frequently, but it goes back to what I've said many times, these still aren't truly professional/broadcast level cameras. And I know major dealers that have told Canon the same thing. They have to build cameras that can play nice with third party equipment. My primary camera is made by Panasonic(2700), the wireless is Lectrosonics, the lens Fujinon and battery Anton Bauer and it all works flawlessly together every time. This isn't the "stills" world where you can close the loop and have your cams only work completely with your lenses, batteries, lights, etc.
 
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