Robert Hart Posted March 26, 2010 Report Share Posted March 26, 2010 Hello all, I Have a few days on a film next week and there using the Sony F35, I was testing it today at the rental house and they were telling me because of the power draw, I think they said it was between 12amp and 14amp depending on accessories, could burn out the post cable on my MK-V Nexas rig. Has anyone else ever heard of this if so is there a way of getting round it? It would put my mind at rest if anyone could shed light on this. Thanks Rob Quote Link to comment Share on other sites More sharing options...
Premium Members Eric Fletcher S.O.C. Posted March 26, 2010 Premium Members Report Share Posted March 26, 2010 I Have a few days on a film next week and there using the Sony F35, I was testing it today at the rental house and they were telling me because of the power draw, I think they said it was between 12amp and 14amp depending on accessories, could burn out the post cable on my MK-V Nexas rig. Has anyone else ever heard of this if so is there a way of getting round it? It would put my mind at rest if anyone could shed light on this. They are correct, Your post is wired with 22ga wire and that's only good for ~4-6 amps, you will have VERY short battery life and the cable will over heat. You will also have issues with both your lower and upper J-Boxes and the Circuit board traces eventually lifting off the circuit board due to the current and heating. I had the MK-V 4 stage Pro Conversion post and it made it impossible to power a Genesis from the sled batteries. Quote Link to comment Share on other sites More sharing options...
Premium Members Brad Hruboska Posted March 26, 2010 Premium Members Report Share Posted March 26, 2010 You can always go two piece and power the camera directly from its on-board adapter, which will run off of one battery itself or through a 4 pin XLR input. Its the deck that sends the power draw way up. Quote Link to comment Share on other sites More sharing options...
Premium Members Iain Baird Posted March 26, 2010 Premium Members Report Share Posted March 26, 2010 Hello all, I Have a few days on a film next week and there using the Sony F35, I was testing it today at the rental house and they were telling me because of the power draw, I think they said it was between 12amp and 14amp depending on accessories, could burn out the post cable on my MK-V Nexas rig. Has anyone else ever heard of this if so is there a way of getting round it? It would put my mind at rest if anyone could shed light on this. Thanks Rob I've done a complete rewiring of my PRO, MK-V hybrid for this very reason! After having success with my upgrade our local Panavision Tech and I designed an upgrade for the Nexus that at least allows you to share the load between two batteries. It gives you back the separately fed auxiliary power plug that MK-V for some reason eliminated. You are still limited by the gauge issues but by dividing the load between two runs you at least stand a fighting chance. The only catch is that the AR run is sacrificed, so no more AR!! For most people this won't be an issue but if you fly one or plan on it then it won't work. Good luck, IAIN Quote Link to comment Share on other sites More sharing options...
Robert Hart Posted March 27, 2010 Author Report Share Posted March 27, 2010 Thanks for getting back to me so quickly. Your replies have been really helpful. Cheers Rob Quote Link to comment Share on other sites More sharing options...
Premium Members RonBaldwin Posted March 27, 2010 Premium Members Report Share Posted March 27, 2010 Just stepped in to sub for an op on a tv show -- used his nexus powered by steadicam power cubes with the f-35/ssr. I wasn't really paying attention at the time and didn't think about it until I came across this thread but we were getting some low voltage warnings on the camera. The batteries weren't hot off the charger but were reading full or almost full (3 or 4 led's on the batts). Everything worked fine but we didn't know what was going on. Maybe it was the afore mentioned voltage loss up the pipe? rb Quote Link to comment Share on other sites More sharing options...
Premium Members Iain Baird Posted March 27, 2010 Premium Members Report Share Posted March 27, 2010 Just stepped in to sub for an op on a tv show -- used his nexus powered by steadicam power cubes with the f-35/ssr. I wasn't really paying attention at the time and didn't think about it until I came across this thread but we were getting some low voltage warnings on the camera. The batteries weren't hot off the charger but were reading full or almost full (3 or 4 led's on the batts). Everything worked fine but we didn't know what was going on. Maybe it was the afore mentioned voltage loss up the pipe? rb This is exactly what led me to upgrade my wiring except it was with an F900 but the same symptoms. A battery hot off the charger was reading full on the battery mount but the camera readout was indicating a low voltage. After improving the post cable gauge the problem was cured and got even better still when I modified the topstage to get the separate AUX feed back. I've never had a problem with any camera since. IAIN Quote Link to comment Share on other sites More sharing options...
Premium Members Alan Mehlbrech Posted March 27, 2010 Premium Members Report Share Posted March 27, 2010 Hello All, I ran into this as well with my MKV- Chris Konash ( www.eastcoastcables.com ) -solved the problem by making a jumper at the base of my V2 electronics and using the AR lines up the sled to run two 12volt lines up. He then made a "Y" cable at the top to power the camera. Everything is 12 volt on the camera so tell the AC to have a Cinetape cable that is for 12v. Otherwise I have had great run life on both Powercubes and AB HC's. Regards, Alan Quote Link to comment Share on other sites More sharing options...
Rick Tullis Posted June 18, 2010 Report Share Posted June 18, 2010 In July I'm going to shoot a feature on an F35 using a MK-V rig. I have read the posts on this forum about possible power problems using an F35 and this sled and it has left me a little confused. Looking at the F35 manual it says the camera head draws 56 watts. So, by my math, 56w divided by 14v equals 4 amps. Right? And that shouldn't be a problem. Someone on this forum said the F35 draws 12-14 amps. How can that be? Are they also powering the deck off of the sled? Or am I really missing something? As someone on the forum suggested, I sent an email to Phil Cremer at Panavision Toronto but I didn't get a response back. And, by the way, I tried to search for how much wattage a typical film camera draws (say an Arri Lite) but I can't find that info. Does anyone know how many watts an average film camera uses? Thanks, Rick Quote Link to comment Share on other sites More sharing options...
Premium Members RonBaldwin Posted June 18, 2010 Premium Members Report Share Posted June 18, 2010 In July I'm going to shoot a feature on an F35 using a MK-V rig. I have read the posts on this forum about possible power problems using an F35 and this sled and it has left me a little confused. Looking at the F35 manual it says the camera head draws 56 watts. So, by my math, 56w divided by 14v equals 4 amps. Right? And that shouldn't be a problem. Someone on this forum said the F35 draws 12-14 amps. How can that be? Are they also powering the deck off of the sled? Or am I really missing something? As someone on the forum suggested, I sent an email to Phil Cremer at Panavision Toronto but I didn't get a response back. And, by the way, I tried to search for how much wattage a typical film camera draws (say an Arri Lite) but I can't find that info. Does anyone know how many watts an average film camera uses? Thanks, Rick I am kinda curious myself -- I imagine that the printed 4 amp draw is while rolling (when the fan is off). Also remember all the other accessories you might be powering off your rig. On my last shoot I had the OB1 drive plus the usual the camewave/wevi, 2 preston motors and cinetape (the pkg was a real pig -- had to be in the 37 lb ballpark with the master-primes and two filters). rb Quote Link to comment Share on other sites More sharing options...
Premium Members Charles Papert Posted June 18, 2010 Premium Members Report Share Posted June 18, 2010 The high wattage draw is of course when the SRW deck is docked to the camera in the dreaded one-piece mode. The numbers I heard years ago were for the Genesis and they were roughly 6 amps for the camera head and 6 for the deck. Quote Link to comment Share on other sites More sharing options...
Rick Tullis Posted June 19, 2010 Report Share Posted June 19, 2010 Charles, Thanks for quick response. I was actually thinking that large power draw must be for the camera and deck docked together but I wanted to double check. And, the other question I asked. Any idea what a typical film camera draws for power? I saw where Arri says the Alexa will draw about 100 watts. Cheers, Rick Quote Link to comment Share on other sites More sharing options...
Premium Members Eric Fletcher S.O.C. Posted June 19, 2010 Premium Members Report Share Posted June 19, 2010 Charles, Thanks for quick response. I was actually thinking that large power draw must be for the camera and deck docked together but I wanted to double check. And, the other question I asked. Any idea what a typical film camera draws for power? I saw where Arri says the Alexa will draw about 100 watts. Cheers, Rick The Alexa doesn't draw 100watts it draws 2 amps at 24volts or 48watts Quote Link to comment Share on other sites More sharing options...
Rick Tullis Posted June 20, 2010 Report Share Posted June 20, 2010 The Alexa doesn't draw 100watts it draws 2 amps at 24volts or 48watts I thought that sounded too high too, but there is a post on CML from Bill Lovell at Arri London saying that ARRI estimates the Alexa will draw 100 watts when recording on SXS cards and a powering a viewfinder. I had an Alexa on my sled last week for testing and it seemed to be ok. (That is, my sled didn't start smoking and smelling funny!) I wonder what the real story is.... Quote Link to comment Share on other sites More sharing options...
Moderators Alec Jarnagin SOC Posted June 20, 2010 Moderators Report Share Posted June 20, 2010 Guys, the Alexa will run off of 12 volts or 24 volts thus the discrepancy noted. Both of you are correct depending on the voltage. Quote Link to comment Share on other sites More sharing options...
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