D-Tap Power for 7D & 5Dm2
 

Switronix has released a power adapter to power the 7D & 5D Mark II. I hooked it up to an Anton Bauer battery and was able to run the camera for many hours. Read my post about it here - Canon 5D/7D Power Tap Adapter | CineTechnica

I was wondering when someone was going to do this. Looks like you still have to buy Canon's AC adpater. It something I had played with using the AC adapter cable, and running to 12 volt.

I'd been looking at this--it's simply a power regulator, no? >12v to regulate 7.9v? Wasn't sure if there were additional electronics in it--I think the critical ones are in the Canon dummy battery cable?

Charles -- the dummy battery has the circuits to tell the camera that it is an A/C adapter and that it is ok to power up. If you have a good 8V power source, the camera doesn't care how it is fed into the barrel connector on the dummy.

Chris -- did you try running the camera at +12V? That would simplify things if it wasn't necessary to step down to 8V like the A/C adapter. Since the battery voltage varies it seems that there must be some tolerance inside the body for a range of voltages.

It has a power regulator in it to adapt the 12v+ source to 7.9v. Additionally it has another D-Tap so you can power 12v accessories as well. It uses the standard Canon dummy battery to power the camera, which is an additional piece to buy but it works well.

Thanks gents.

You know, this inspired me to look up for once and for all the right answer to the question--is it P-tap or D-tap? And much to my chagrin I see that while the official Anton Bauer name is Power-tap, other manufacturers call it D-tap and I've been saying P-tap all these years. D-tap it is. Thanks Andy!

Hum... a bit off topic, but I have the Anton Bauer Gold plate for the XLH1 and I don't use it anymore. Since it must output someting like 7.2V, I wonder if I could not replace the dummy XL battery by the dummy 7D battery and use it to power the 7D ? What do you think?

Battery Warning Still Work?
 

If the battery (whatever that may be, switronix, anton bauer) is almost dead, does it tell the camera too? I dont want it turning off in the middle of a take and losing that footage forever.

Tramm:

Sorry I missed this earlier. No I haven't tried yet. Camera at repair for hot pixel. I did intend to figure out a how to drop the voltage to 8 Volts.

Missed this before. I've been running a 7.2v dummy battery hardwired into an old IDX battery plate designed for the Canon XL1. Works a treat with both 5D and 7D and has a 12v d-tap as well.

Dan

Dan, could you elaborate on what you mean, and do you have a picture of what you are talking about?
What voltage are you feeding the 5d/7d?

The 7D is being fed 7.2v because in the IDX plate for the XL-2 there is a little step down circuit with reduces the v battery's output. I simply unsoldered the XL-2 connector and replaced it with a Canon 5DmkII, 7D dummy battery.

It also has a 12v d-tap on the plate as well.

Dan

Re: D-Tap Power for 7D & 5Dm2
 

Sorry to revive a necro post. I'm looking in to getting a Steadicam Pilot and I've never used the larger pro batteries. So, I need either an Anton Bauer, IDX, or some other battery with a DTap and this adapter? Could I also run the monitor and electronic follow focus off of it?

Related question - should I pass on the kit monitor and go with something with features better suited to a DSLR? Like a SmallHD or one of the new Marshalls that adjusts to the 5Ds changing HDMI output?

Re: D-Tap Power for 7D & 5Dm2
 

Good questions Kevin, and you are heading in an intelligent direction with the gear. While it is cheaper to go the AA route, if you go with a standard manufacturer battery in either gold mount or v-mount as you indicated, you will be able to use those batteries on cameras down the road as well. I have long been a proponent of powering things off as few batteries as possible. I find it a little amazing that folks are satisfied with powering their DSLR off an internal battery, then powering their onboard monitor with up to two more batteries, then if they have any other components onboard they get their own battery--then you put the whole thing on a stabilizer which has it's own battery. While flying this setup, each battery you have in the system will go down at different rates and it's a real pain to keep track of. When the picture dies, you have to go through and figure out which piece of the puzzle is responsible. Ugh.

So yes, you are better off powering off the sled's battery. Use a power adaptor for the camera. I think Tiffen sells a bare lead cable that plugs into the top stage--you can buy the Anton Bauer 4-way powertap splitter and splice the two together, then velcro that under the stage and you are set to power 4 components.

As far as replacing the Pilot's monitor--it's not the worst idea in the world as that monitor is not exactly world-class, however it is treated for anti-reflection and will do a bit better in sunlight than the ones you mentioned. Forget using any kind of wraparound sunshade with a Steadicam monitor--you need to be able to view off-axis at any given time. Also bear in mind that using anything other than a composite video signal will require running the appropriate cable (i.e. HDMI) from the top to the bottom of the sled (best done from the front of the stage directly down to the monitor). It doesn't get in the way of standard operating but it's not the cleanest look, and it can get caught on things--so if you do this with an HDMI cable, make sure it is strain-relieved at both ends.

Now--which "electronic follow focus" were you thinking of....?

Re: D-Tap Power for 7D & 5Dm2
 

Thanks for the insight and advice - I hand thought directly after posting that the cabling would be all wrong for an HDMI based solution, but figured there wasn't a work around (mostly because I'm not sure what can and can't connect to each other and not ruin the stabilization).

As for the follow focus… I'm not sure. The only one I've actually seen/held is the brand new jag35 wireless unit and I'm not 100% sure what to even look for. Any thoughts on this?

Re: D-Tap Power for 7D & 5Dm2
 

You can see an external HD-SDI cable working in this DSLR setup on my little rig (I've since run SDI down the post):

MobileMe Gallery

Saw the video on the JAG unit, it seemed pretty speedy and obviously inexpensive. Would be curious to see what kind of range it has and how impervious it is to transients and interference. I've felt for the last couple of years that the first company to market with an under-$1K wireless focus system will clean up. There have been a few that have tried and had a tough time of it, or morphed into higher-cost versions. Redrock is working hard on theirs but it is still a work in progress. This is a tough technology to crack for low cost. I've seen a few efforts try and fail in recent years.

Re: D-Tap Power for 7D & 5Dm2
 

Our current thinking - and please tell me if it's flawed - is to have a monitor at the camera, turned outboard for our focus puller to use, so he'd be wireless on the focus, but right next to the unit. That said - what wireless unit do you recommend? I guess since the lower monitor is just for framing, if the 5D will output HDMI and composite at the same time, we could keep the original Pilot monitor - that would keep us from buying two monitors to go with it (unless there's a way to get the Pilot without a monitor).

Re: D-Tap Power for 7D & 5Dm2
 

Well, this is where things get interesting. The indie world has largely not experienced wireless lens controls yet and I imagine that when this becomes mainstream, it will likely be used differently than what I'm used to (having owned them for 20 years or so). An example of this would be the recent availability of large sensor cameras. For those of us who came up in the 35mm cine world, there was a learned application of depth-of-field and understanding of the ramifications of shooting wide-open and the resulting focus issues. Even the best AC's would miss moments at stops under 2.8. I would have thought that with the DSLR's, especially the 5D with its wide field of view and most people pulling their own focus off tiny screens, there would be an instant backlash to the wide-open shallow look since there would be so many focus issues. Yet the 50mm 1.2 remains a prized lens, and folks are apparently either satisified with the hunting-focus look or cutting around otherwise great material that came in soft instead of sacrificing a few stops of depth of field.

So along those lines: traditionally Steadicam focus was done by feel and zen and a lot of skill on the part of the AC, who had to calculate distances on the fly and dial in numerically (film taps offered little in the way of feedback on this). Since the advent of large sensor HD, more than a few AC's have taken to integrating a monitor into their setup, although the preferred method is to have their own unit within visual distance of the camera, sort of triangulated from the action so they can watch the relationships and only refer to the monitor at specific times. Newer AC's seem to like to pull from the biggest monitor on set, purely visually, although I have yet to see them turn in work that is as accurate as they are reacting to focus after the fact, not necessarily anticipating.

It will be tough for an AC to keep up with a Steadicam operator if he is referring to a camera mounted monitor, especially if the shot requires panning to any degree (he will be running around the camera like a crazy person). If this has to be the case, your best bet is to mount the monitor to the rear--if you have to walk through any tight spaces like a hallway, this will maintain him being able to stay behind you. Along with affordable wireless focus we are also seeing the emergence of affordable HD transmission (Teradek) which will eventually result in the AC being able to carry his own monitor wirelessly, perhaps even an iPad.

But as I said--no doubt the indie world will come up with some new methodology to get the job done that will surprise me. We'll see.

Re: D-Tap Power for 7D & 5Dm2
 

That's a lot to think about.

I think for our main usage (at least perceived/anticipated usage) we'd be tracking with a talking head - so there's be less wild running around trying to keep up with focus and unfortunately we're not going to have extremely experienced AC's, but we'll train them as we go along I suppose.

As for the crazy shallow DOF with the 5D, I prefer to actually have my footage in focus and am not a huge fan of the "focus hunt" look... So we (with viewfinders like the ZFinder) have done our best to figure out how to keep these things in focus - we certainly have had to reshoot a few takes more than we ever did on the DVX, but the pain of learning is worth the jump in image quality.

I guess ideally we'd have a wireless video tap - but I don't know that I want to add that expense (and weight) to the setup at the moment...