Moviecam Compact Mark2 3-perf & 4-perf options

AmatEscalante · December 25, 2017

Hello,

I was wondering if any Moviecam Compact Mark2 is inherently easy to switch between 4-perf and 3-perf movement.

Thanks for your help!

Tyler Purcell · December 25, 2017

The problem with the Moviecam SLMKII and Arricam LT is that, the sprocket drive is the same motor that runs the movement. So when you switch formats from 4 perf to 3, or 2 perf, you need to also slow down the sprocket drive, but keep the main movement running at the normal speed. This is achieved through different gears on the sprocket side, with an alternative belt drive on a few of the cameras. I'm not sure how the SL/LT does this, as I've never done the swap. I would make the assumption it would be like the rest of the cameras.

The only camera that's capable of switching formats on the fly is the Aaton Penelope. This is because the sprocket drive is part of the magazine, so in software its easy to simply adjust the drive motor speed, which is for both the sprocket AND the take up. Can't do this with any other camera that I'm aware of.

Dom Jaeger · December 25, 2017

I've converted Moviecams and Arricams between 3 and 4 perf many times. The first time requires some measurement and adjustment to correctly fit the movement (the part that contains the pull down claws and registration pins) to the camera, a couple of extra hours for a trained technician. Once the correct shimming has been calculated, and the movement checked and adjusted if necessary for that particular camera, all subsequent conversions are a fairly simple matter of fitting the new movement and its shims, fitting the new gate, swapping a sprocket drive belt gear and belt, and flipping a switch on a circuit board. It should take about 2 hrs. It's recommended to shoot a test after a conversion, but mainly as an insurance, we never had an issue.

If a rental house has the conversion kits it's a simple matter to convert formats. If an owner/operator wants the option, they would need to buy the conversion kit, which is a whole new movement and gate, plus a gear and belt and shims, and then have it installed by a qualified tech.

Edited December 25, 2017 by Dom Jaeger

AmatEscalante · December 25, 2017

Thank you both for you knowledge and insight. I had an understanding from the Compact Mark2 manual that: "Because the three perforation image acquisition technology seems to have a strong revival now, both ARRI-CAM cameras as well as the upgraded MOVIECAM COMPACT Mk2 enable shooting either with 4 or 3 perforation pull-down. "

Therefore I would understand that the camera system is relatively easy to switch between 4 and 3 perf on any Mark2? That was my specific question for anyone with direct experience on a Compact Mark2.

Dom, so have all the Mark2s been factory modified so that all I would need is a conversion kit and a qualified tech?

Tyler Purcell · December 25, 2017

Whoops... you did say compact MKII lol my bad!

There is no difference, it's all the same amount of work.

Again, there is only ONE camera with semi-easy switching between 3 perf and another format, in it's case 2 perf, which is the Aaton Penelope.

Dom Jaeger · December 25, 2017

Dom, so have all the Mark2s been factory modified so that all I would need is a conversion kit and a qualified tech?

Yes, they all convert as I described. Moviecam Compact MKIIs and Arricams all utilise similar conversion kits, and in fact the same 3 and 4 perf movements.

Finding a Moviecam Compact II conversion kit could be difficult however. The company no longer exists and Arri doesn't support Moviecam products. Your best bet is probably a rental house, but it may be easier and possibly even cheaper nowadays to buy a whole camera already in the format you want. Those kits were very expensive when new, tens of thousands of dollars.