Arri BL4S, 3-perf and Super 35

[John Jaquish]

Hello,

 

I'm looking into using the BL4S for a project and wanted to clarify something (or rather have something be clarified for me). From what I understand, the BL4S has the ability to switch between Super 35 and Normal 35. Additionally, it has the option of shooting with 3-perf negative pulldown. Is the latter option standard, or are there BL4Ss that shoot only 4-perf? Finally, is it designed to be easily modified from 4-perf to 3-perf, say, on set? Or is it a permanent conversion to be made in house?

 

Thank you very much for any information.

[Dom Jaeger]

If the camera has a PL mount with '1' and '2' printed on it switching between Super and Standard is easy, the 6 mount screws just need to be undone, the mount rotated 180 degrees and then re-secured. When the '2' is at top right the mount is centered for Super. (The PL locating pin also needs to be shifted back to its original position, the baseplate adjusted, and maybe the video tap re-centered, all easy to do.) It's a good idea to check the camera flange focal depth afterwards, even though most of the time it stays the same.

 

Converting between 4-perf and 3-perf is a much bigger job, definitely not something that could be done on set. The whole movement needs to be replaced, plus modifications done to the sprocket drive timing and footage counter. I'd hazard a guess that most BL4Ss would stay permanently converted, unlike Arricams which can be converted in-house in about half a day. I'd also guess that the standard option for BL4Ss was originally 4-perf.

[John Jaquish]

If the camera has a PL mount with '1' and '2' printed on it switching between Super and Standard is easy, the 6 mount screws just need to be undone, the mount rotated 180 degrees and then re-secured. When the '2' is at top right the mount is centered for Super. (The PL locating pin also needs to be shifted back to its original position, the baseplate adjusted, and maybe the video tap re-centered, all easy to do.) It's a good idea to check the camera flange focal depth afterwards, even though most of the time it stays the same.

 

Converting between 4-perf and 3-perf is a much bigger job, definitely not something that could be done on set. The whole movement needs to be replaced, plus modifications done to the sprocket drive timing and footage counter. I'd hazard a guess that most BL4Ss would stay permanently converted, unlike Arricams which can be converted in-house in about half a day. I'd also guess that the standard option for BL4Ss was originally 4-perf.

 

Just the information I was looking for. Thank you.