How I Learned to Stop Worrying and Love the Powertap
Posted 09 November 2009 - 08:20 PM
The venerable Powertap (as Anton Bauer calls it, the other manufacturers reverting to the generic D-tap) has become something of a universal currency now in the HD world. Since it is supported and available by all major battery manufacturers, it's more than worthwhile to take this one seriously and equip oneself with a variety of options of all genders. I have in recent months talked to a number of operators who would have been saved a lot of grief had they owned a simple cable that would have solved any number of issues. It's a real shame to have to gaff a camera plate with battery to the top of the rig simply to provide a way to power a component, especially when that component is often a fraction of the weight of the battery! Herein: my suggested cables that I am using on a regular basis.
1) Sled to female d-tap. This will be a custom cable, but it will provide you with the ability to provide a d-tap source from your rig without relying on the camera to do so. This may allow you to shed weight off the camera. In the case of RED, it's well known that flying the onboard battery often requires a depressing amount of bracketry (hopefully ET but more often than not the lumbering RED stuff with steel 19mm rods, ugh); powering the camera off the sled with the appropriate cable is good but you still might have to power accessories, and by removing the battery you will have disabled the d-tap port. This particular cable has elicited many a "huh, that's a good idea" from other operators when I describe it, so I feel confident in saying that it's a good idea. I have PRO wiring so I had mine made (by Terry West) with the 3-pin camera power Lemo.
2) In conjunction with the above, the Powertap Multi which plugs into a d-tap port and provides 4 outputs. Bite-sized and super-useful if you have multiple components to power. Hence the name.
Sometimes you might find yourself in a situation where it would be a lot easier to switch from Steadicam mode to studio mode without having to recable everything. I do this sort of thing a lot, as do a lot of folks in the hinterlands where you may well be DP'ing as well as operating. Some never use their stuff off the rig, so this may not apply. The easiest way to do this is to use the setup above for Steadicam, making sure everything is powered into the multitap and then when you go to studio mode, simply repatch the multitap into an onboard battery or equivalent (see 4, below). In this instance, some other things that are good to have:
3) D-tap to female 4-pin XLR cable. Useful if you need to power a component that requires this for input (Camwave).
4) D-tap extension cable. Needed one of these recently for a DSLR gig where the battery sat on the dolly on a plate as we didn't have a way to mount it to the camera. Didn't own the cable but Alec J. came to my aid since we were in his neck of the woods. Now I've got my own.
5) D-tap male to any of your regular AKS. I have d-tap cables for my Preston MDR (both the 3 and 1 channels), Modulus, onboard Litepanel setup and a few other obscure items and they get lots of use. If you have a lot of devices that use a common cable end (like the 4-pin video/power Lemo on the PRO/XCS/MKV or the 4-pin Hirose on the Steadicams), you could have a pigtail made with a female version of that connector to a male d-tap that would allow any existing cable to be plugged in to the d-tap port.
6) Finally, I carry a little selection of turnarounds and plates that can help solve problems. I'm a Gold Mount guy so I have a female mounting plate that attaches to the battery and provides a d-tap source (for providing remote power, see 4 above). AB makes one that has 4 D-tap ports built into it as well. I also have one that has a 4-pin XLR pigtail coming off it in case I need to provide that flavor of power. Also I have the reverse, a male plate with built-in 4-pin male XLR connector, which sometimes allows you to power a camera or device via XLR cable (I say sometimes because cameras can be a bit sensitive about this--I've seen where they are "expecting" a battery and don't like the simple voltage you are providing). While many cameras will also have a cabling option like 4-pin XLR, this will activate the d-tap port on the camera's gold mount plate.
7) Not really a d-tap issue but while we are on the subject of mounting plates, I have two of the gold mount to v-mount adaptors and they have saved my bacon a few times. It's always nicer to use up someone else's charging cycles on their batteries rather than our own, so I have occasionally adapted the RED v-mount battery to my sled. Yes, the adaptor does have some play in it so it's no ideal for all applications.
OK, that's a lot of stuff but suffice to say that two years ago I didn't have (or need) any of it, and these days I seem to be pulling it out on a regular basis. Not only that, but I'm also using my d-tap cables. Sorry, couldn't resist.
By the way, with the exception of item 1 and 5 above, all of this is easily purchased from usual sources like B&H. Anton Bauer makes a lot of this but there are alternative vendors out there like Switronix.
If anyone has any other bits along these lines, please post. I'm probably missing something that I may even own already.
Posted 09 November 2009 - 08:38 PM
Just got me wondering, Charles, do the Canon DSLR cameras have an external power input? Is the internal battery easily changed from the back or is the access door underneath the body like some cameras and involve de-riging?
Posted 09 November 2009 - 09:29 PM
Thanks for sharing.
Posted 09 November 2009 - 09:29 PM
The 5D and 7D have a dummy battery that inserts into the cavity which is indeed at the bottom of the camera; the battery dumps straight down so it is a potential conflict depending on how you have the camera mounted. If you use a rig with risers or the Bogen quick release you will likely have enough room to drop the battery (something worth considering when mounting the setup).
The dummy battery cable is a standard Canon part (half of the AC adaptor setup) and it terminates in a typical push-on style connector. At that point it is looking for 7.2v straight voltage, the dummy battery has all of the brains to interpret the power capacity for the camera. Switronix makes a d-tap adaptor to bridge to that cable, but any voltage regulated source at 7.2v would do it. The 1D has a larger battery that feeds in from the lower left side of the camera, which is obviously better but one has to make sure that any extra bracketry or rods are not in the way there.
For my "super-rig" studio setup I am currently looking at having to provide three regulated output voltages: 12v (the Blackmagic HDMI to HD-SDI box is very temperamental about overvoltage); 7.2v for the camera and 5v for the Zoom H4N audio recorder. There may be others down the road so I'm keeping my options open...! Luckily this isn't hard to manage.
Posted 09 November 2009 - 10:03 PM
My BFD, Transmitter, and RED cable have the P Tap on them
Posted 09 November 2009 - 10:05 PM
Posted 10 November 2009 - 09:26 AM
Posted 10 November 2009 - 11:54 AM
Posted 10 November 2009 - 12:09 PM
Posted 10 November 2009 - 12:20 PM
Care to elaborate on this...
Yup, that can happen. A good reminder to wrap the Multitap in velcro or electrical tape to help prevent this.
Posted 10 November 2009 - 12:23 PM
Jim "any port in a storm" Bartell
Posted 10 November 2009 - 12:46 PM
Alfeo, not much to elaborate on. Just tape around the outside to prevent the Multitap from separating...and keep the morons at bay.
Posted 10 November 2009 - 01:09 PM
In regards to the play between the gold mount and v mount adapter, here's a remarkably simple solution. A couple tabs of soft side velcro on the gold mount provides a cushion between the two plates. It pretty much eliminates the play and rattle. Equally effective if there's a bit of play in your AB battery. Works for me, hope it works for you.
Posted 10 November 2009 - 02:54 PM
I have noticed that the Dionic HC's are a much tighter fit by design and don't require the tab.
Posted 10 November 2009 - 04:48 PM
I also use power tap when I have chance for most of video shoot to eliminate the cost of expensive Lemo cables.
Just a reminder, there are expensive D-tap and cheap one.
The expensive good one is hard shell and black in color.
I prefer the one from AB.
The cheap one is the problem one. The shell is soft enough so that a careless AC can force it in the other way (wrong polarity).
It happened to my Bartech already.
Since then, the last thing I hand to any AC is the power cable.