SRII on-board power alternatives?
Posted 06 July 2012 - 11:20 AM
Posted 06 July 2012 - 01:02 PM
Well, Arri on-boards are available from places like Visual Products in Ohio, and will come re-celled and guaranteed, which is nice. It'll cost you though.
If you are looking for more economic solutions, I simply recommend a 12-volt power source that is not made by Arri, like a battery belt. This is different ergonomically from the onboard, but there are a few advantages:
Modern Ni-Cad belts are capable of holding a lot of 12 volt power- one with over 10 amp hours will set you up for AT LEAST a days's shooting, unless you are putting over like 30 x 400' rolls through the camera in one shoot.
Some people prefer the belt to the onboard as the extra weight in on the operator's hips or slung around the tripod legs.
Also, one of the VERY few SR design flaws, in my opinion, is the battery system. It puts stress on the XLR input, even with the magnetic connection between the mag and battery. The connection between the 4-pin to battery mount is also delicate– if an inexperienced assistant wriggles and or twists the battery off the coupler, then that may crack the battery.
Belts are perfectly safe for the SR 1 & 2– if they are 12 volts. I'm a little hazy but I think that 14 volts may be a little high for any original Arr SR I or 2 motor. Maybe not though, I know you can exceed by a little. When possible though, pushing UP on the volt scale is something I avoid with my SRll, for the reason that it is such a great machine that deserves as little stress as possible.
Now, I currently have a 12-volt Bescor battery belt for sale on eBay (sorry, I'll be brief, here not sure if it's appropriate to introduce business to this section of the forum), one that was purchased for with an ARRIFLEX SR ll. If the idea of a belt does not offend you, then this item, or something similar, will solve your power problems– absolutely. It's 12-volt with 12 amp hours, and is in essentially new condition. Perfectly safe for the SR (not the SR 3, which runs on 24v). A real steal, as you will get a new condition belt for about half the NEW price.
As for jerry rigging another camera battery as an onboard– I wouldn't. Camera power is one field that people will explore with many home-made options, which is great, but unless you have old onboards that needs re-celling or something, it may be more trouble than it's worth, and it's possible that the typical Arri onboard problems will only be exacerbated by the unusual design of another system's battery.
Ok, I hope this helps.
Posted 11 July 2012 - 03:54 PM
Posted 13 November 2015 - 12:11 AM
NFL Films engineered a way to use dionics with these cameras, which is pretty cool for field work. You could call their camera department and ask for details, they're very friendly and helpful folks.
Edited by Kenny N Suleimanagich, 13 November 2015 - 12:12 AM.
Posted 13 November 2015 - 11:25 AM
if you are using 19mm rods with your camera you can use a separate v-mount plate which attaches to the rods and then, if the plate does not already have down converter from 14 to 12v, you can add a separate down converter (regulator) between the plate and 4pin xlr. I just ordered some Chinese down converters/regulators from ebay to hack my Cameflex to use 12v input, they are quite affordable and compact. you should test them first though, some of them are very good and some are not, better to know if the output voltage is true 12v or something else and if it can vary depending on conditions
One trick is to use serialised diodes between the battery and the output xlr to lower the voltage if you are always using the battery system with the same piece of equipment so that the current is the same. I think couple of 10A diodes would do for the SR2 although the exact voltage drop is highly dependent on working current and may vary quite much depending on conditions
Posted 13 November 2015 - 11:32 AM
I use this kind of NiMh airsoft batteries with most of my 12v film equipment, I have attached velcro on them so I can simply attach them to velcro surfaces (for example to the side of my Konvas sync motor) and I have made adapters from tamiya to 4pin xlr for the camera gear or changed the battery connector to 4-xlr. the cells discharge in couple of weeks but otherwise good batteries in general and if you velcro them you can attach them easily anywhere although they are relatively long and quite large compared to similar capacity Li-po or Li-ion batteries....