DIY 2-Perf Techniscope conversion? For Real?

Samuel Berger · September 21, 2017

I saw this:

His explanation: "sheet metal, laser cut 9.45 mm 22 mm and pasted. polished. sorry use translator"

Results:

Is that really all it takes?

You can see he just masked half of the film, then rewound the film and used the same roll again. It's more like split-screen than actual 2-Perf. Any drawbacks to that process?

Edited September 21, 2017 by Samuel Berger

Tyler Purcell · September 21, 2017

For that particular camera, yes...

If you line up the film properly with the proper gate, you can do it.

Samuel Berger · September 22, 2017

Has anyone who speaks English tried this? ;-) It would definitely give me a reason to buy an Arri 2C.

Dom Jaeger · September 22, 2017

For that particular camera, yes...If you line up the film properly with the proper gate, you can do it.

Why do you say only for that particular camera?

Tyler Purcell · September 22, 2017

Why do you say only for that particular camera?

You're saying the trick will work for ALL cameras?

Dom Jaeger · September 22, 2017

I don't see why it wouldn't work on other 4 perf 35mm cameras. You just need to mask off a 2 perf frame. Lots of cameras have slots at the gate for masks, you could easily make a 2 perf one. You mark a few frames at the start, then when you go for the second pass make sure you line the film up with the unmarked area. Trickiest part is probably separating the 2 different streams in the scan, though I'm sure it wouldn't be that hard.

With the 2C version pictured where he presumably masked the top or bottom half of the frame you might get some issues with the image not being centred with the lens, ie zoom tracking or offset distortion, but it wouldn't be as noticeable as left to right offsetting.

Pavan Deep · September 22, 2017

I have similar techniques used on Eyemos;

http://eyemorexfinder.webs.com/2perfreflexeyemo.htm

Pav

Aapo Lettinen · September 22, 2017

I don't see why it wouldn't work on other 4 perf 35mm cameras. You just need to mask off a 2 perf frame. Lots of cameras have slots at the gate for masks, you could easily make a 2 perf one. You mark a few frames at the start, then when you go for the second pass make sure you line the film up with the unmarked area. Trickiest part is probably separating the 2 different streams in the scan, though I'm sure it wouldn't be that hard.

With the 2C version pictured where he presumably masked the top or bottom half of the frame you might get some issues with the image not being centred with the lens, ie zoom tracking or offset distortion, but it wouldn't be as noticeable as left to right offsetting.

one could either ran it through the scanner two times with 4perf pulldown but masking first the upper part of the image and then the lower part. But it would be more economic, if getting enough vertical resolution from the scanner, to scan the whole 4perf open gate area (the two streams at the same time) and then separate them in edit (very easy to do).

of course the whole roll will be ruined if one screws up aligning the film perfectly at the start of the roll when shooting the second pass. similarly, if one has problems in the middle of the roll and needs to open the movement, the alignment will be ruined and one may need to leave the rest of the roll unexposed which ruins the cost-effectiveness.

as others said, should work OK with every camera which can use separate gate masks. rewinding the film will make changing the rolls a bit complicated and will add some dust to them which may be a problem in 2perf.

other way to do it would be to leave the end of the roll, maybe about 20 or 30ft or so, unexposed. to stop the camera before the roll ends and before the stock is running too low on the feed side, then mark the PASS1 framelines to couple of adjacent frames, then running the camera couple of feets so that you can get enough tail for threading the camera again. then cutting the film and throwing the rest 15-25feets of the raw stock away, flipping the takeup side roll to the feed side, threading the camera, aligning the film so that the PASS1 framelines DO NOT show in the gate (so that you are exposing for the 2ND PASS areas) and then shooting the second pass.

Edited September 22, 2017 by aapo lettinen

Aapo Lettinen · September 22, 2017

daylight load cameras like Eyemos would be easier to use for this technique because it is much easier to find the frame markings at the start of the roll when you can handle the rolls in daylight. Quick change magazines are very tricky for this, especially the Konvas cameras where you need to open and realign the magazine in changing bag instead of just adjusting the film position just before attaching the magazine to the camera (the Konvas movement will jam if your loop are wrong size by about 1 or 2 perforations so you can't really adjust the film position in other way than opening the magazine in changing bag every time you have adjusted the position so that you can correct the loops, then reattaching the mag to the camera and hoping that the alignment does not change from your last adjustment....

you should have a mark near the frameline marks which you can feel in the changing bag so that you can approximate the film position when loading the magazine. a small punch for example. otherwise would be too time consuming to use this method with most cameras, especially the quick change mag ones where you can't just wind the mag forward to find your markings

Aapo Lettinen · September 22, 2017

With the 2C version pictured where he presumably masked the top or bottom half of the frame you might get some issues with the image not being centred with the lens, ie zoom tracking or offset distortion, but it wouldn't be as noticeable as left to right offsetting.

it would always be best to use centered masking for the 2perf area. in telecine/scanning one just needs to offset the image so that the both passes are visible. because the film is aligned in camera only by the markings it would not matter whether one would mask centered or off-centered but for the image the centered method would be much much better

victor huey · October 14, 2019

or just buy a two perf camera, lol......takes a while to find them but they are out there!

Robino Jones · October 15, 2019

I would be very curious to do a test with my AATON 35III just for fun. I don't have my camera with me at the moment but I saw an old post of someone selling a Aaton 35III and he listed a "1.85:1 gate mask" as part of the package.

see post here: https://steadicamforum.com/index.php?app=forums&module=forums&controller=topic&id=15503

Anyone knows if there's a slot on the AATON 35III for gate masks?

If there is I'm pretty sure I could build one.