How to do in camera double exposure? (SR2 S16)

Noé Cornago · September 7

Hey all, I want to try an in camera double exposure with my Arri SR2 S16, but can't really wrap my head around how to do it.

Few things I'm trying to figure out:

Since it can't rewind on its own, what's the best way to rewind it externally, is there a go to tool or accessory people use, or does it depend on the mag? I don't really care about getting the exact frame count accurate, just want the two exposures to roughly line up.

How do you compensate so it doesn't just blow out when you combine two exposures? Do you stop down a stop on each pass, underexpose both, something else?

I'd love to see examples if you've got them, music videos, shorts, whatever. Just trying to get a feel for how it looks in practice and how people pulled it off technically.

Any advice or "don't do it like this" warnings welcome, thanks in advance.

Thanks everybody

Noé Cornago

Tyler Purcell · September 7

Sadly you can't rewind on a SR magazine without opening up both doors.

When you drive the sprocket backwards, (or even turn the supply backwards) the take up runs at a much faster speed, so within a few dozen turns, it will start to jam. The only way to solve the jam is to basically hold the take up with your hand so it doesn't wind faster then the supply. So this means, both doors need to be open in the changing tent and you have to very slowly wind it whilst keeping pressure on the take up.

The best double exposure camera I've owned is the Beaulieu R16 or 2016, because they have a motorized rewind with a counter. So you can go right back to where you want exactly, to the frame by simply adjusting the motor speed (slowing it down to get precision). You can't really do that on an SR unless you are literally making a hole punch in the film and then feeling with your finger where that punch is. So you're libel to scratch/damage the film.

You could make a hole punch where you want to start the double exposure at the beginning of the roll. Then rewind it all the way and simply re-thread to that hole punch. That's one way of doing it. Another way is to cut the roll, rewind and re-thread as just a short end. The hole punch needs to be super small tho, so you'd need to find some sort of punch that is tiny. It can't damage the film or the lab may not process it out of an abundance of caution. If you're doing multiple double exposures on a single roll, it's way cheaper and easier to just buy a camera that can do it easier like the Beaulieu R16 or 2016. I service them and really like them, many of my clients have them and do double exposure all the time with them. Bolex's are another option, but it's a pain due to the manual rewind process, vs electronic.

In terms of other cameras, in the world of commercial 16mm there aren't any that go both ways. With 35mm there are way more choices because most of the motion control and animation work was done on 35mm cameras. So Fries/Mitchell, Acme and Bell and Howell 35mm cameras for the most part, can go both ways. The early Arri 35mm cameras have the capabilities too, but not in every magazine. The Arri 435 is the most famous bi-directional 35mm camera, it's a basically "do everything" camera, but at a cost of course. There are others, but suffice to say with 16mm the choices are more limited.

In terms of exposure, yes I would just slightly under expose on each, maybe by a stop. As long as there isn't massive highlight blooming and you're shooting negative, you'll be fine.

Send me a DM, I can send you some samples.

Edited September 7 by Tyler Purcell

Brandon Paterno · September 7

rewind it externally in a changing tent. unless the mags have rewind clutches you’ll have to take the film out and do this with split reels or by hand…

if the cam can handle it i’d be determining the lengths of the shots preemptively and then cutting up the raw stock while attaching leader to the beginning and ends. but that would be in an ideal world. dunno how the arri would cope

Brandon Paterno · September 7

and i agree with tyler re using a different camera. rent a bolex or a beaulieu…

the bolex rewind claw (pull-up claw? haha) works really well for maintaining the frame lines if that’s what you care about. the bolex uses a two claw system that changes back and forth in sort of a clever way. beaulieus shift a little bit, but reset the moment you drop back into fwd. the claw shape is the reason for this — so ultimately it depends on what you want to do.

i’ve heard that bolexes can jam when going back and forth using an external motor but i think that’s likely an indicator of a camera sided issue (wear on the movement and washer springs etc).

Tyler Purcell · September 7

4 hours ago, Brandon Paterno said:

i’ve heard that bolexes can jam when going back and forth using an external motor but i think that’s likely an indicator of a camera sided issue (wear on the movement and washer springs etc).

Yea if you're doing long double exposures it can be a problem, short ones aren't tho. Bolex's are pretty reliable in this way.

Dom Jaeger · September 8

I've had to rewind film in an SR many times doing steady tests. It's definitely not as easy or as controllable as with a Bolex or Beaulieu, but it can be done.

The safest way is to remove the film from the mag and rewind it in a darkroom with some rewinds.

You can do it with the film in the mag if you're not too worried about cinch marks by doing the following in a change bag or darkroom:

Unlatch the film from the hooks on the pressure plate. Open both doors of the mag and secure the take-up roller arm out of the way. Use your left hand to manually wind the film back onto the feed spool while your right hand lightly keeps the film in the plane of the take-up spool. Because the drive gear turns the take-up spindle at a faster rate than the sprockets feed through film, when you reverse the direction the film will slowly unravel on the take-up, so you need to keep it in place and before it unravels too much, periodically wind the take-up back tight while holding the drive gear with your other hand. It's a bit annoying but OK for shorter lengths like a steady test. For actual footage you want to use, like double exposure experiments, I would recommend removing the film and using rewinds.

The other issue with using SRs for double-exposure is that they don't have a frame counter to accurately gauge where you might want to overlap scenes, so you would need to estimate it from the footage counters.

The best camera for doing 16mm double exposures I think is the Bolex. In a properly maintained camera the frame counter is very accurate and counts up to 1000 frames, and the camera has a dedicated second claw for cleanly moving the film in reverse. It will not jam or damage perfs unless the camera is poorly calibrated or damaged. Bolexes were the animation and experimental film camera of choice for decades for a reason. But you could also use a Beaulieu, Cine Kodak Special, Arriflex 16 St or any other 16mm camera that has a frame counter and the ability to run in reverse or use a rewind crank. The frame counters on these cameras tend to reset much quicker than a Bolex though, only 100 frames on a Beaulieu or 40 on an Arri St for example.

Brandon Paterno · September 8

if i recall the bolex is the only 16 camera to have a second claw to handle frame line consistency while running in reverse?

the 100 frame thing on the beaulieu is particularly frustrating. when the frame counter of the bolex works (and in most cases it should unless some parts have worn down) it’s a real thing of beauty. they’re the go to camera for small scale optical printing after all…

part of why i’m refreshing the beaulieu r16 hardware is because of the 100 frame counter reset. it’s kind of spiraled out into some pretty neat awareness features like arbitrary frame constraints you can set to shoot exact amounts and or trigger a reverse upon a reached frame.

Noé Cornago · September 8

Thanks a lot for your help guys,

I don't really mind taking the film out of the mag and onto the tent, I just want to experiment so don't really need to be accurate on the timings or anything.

So I should underexpose by a stop both images if I understood correctly?

Noé Cornago · September 8

18 hours ago, Tyler Purcell said:

Sadly you can't rewind on a SR magazine without opening up both doors.

When you drive the sprocket backwards, (or even turn the supply backwards) the take up runs at a much faster speed, so within a few dozen turns, it will start to jam. The only way to solve the jam is to basically hold the take up with your hand so it doesn't wind faster then the supply. So this means, both doors need to be open in the changing tent and you have to very slowly wind it whilst keeping pressure on the take up.

The best double exposure camera I've owned is the Beaulieu R16 or 2016, because they have a motorized rewind with a counter. So you can go right back to where you want exactly, to the frame by simply adjusting the motor speed (slowing it down to get precision). You can't really do that on an SR unless you are literally making a hole punch in the film and then feeling with your finger where that punch is. So you're libel to scratch/damage the film.

You could make a hole punch where you want to start the double exposure at the beginning of the roll. Then rewind it all the way and simply re-thread to that hole punch. That's one way of doing it. Another way is to cut the roll, rewind and re-thread as just a short end. The hole punch needs to be super small tho, so you'd need to find some sort of punch that is tiny. It can't damage the film or the lab may not process it out of an abundance of caution. If you're doing multiple double exposures on a single roll, it's way cheaper and easier to just buy a camera that can do it easier like the Beaulieu R16 or 2016. I service them and really like them, many of my clients have them and do double exposure all the time with them. Bolex's are another option, but it's a pain due to the manual rewind process, vs electronic.

In terms of other cameras, in the world of commercial 16mm there aren't any that go both ways. With 35mm there are way more choices because most of the motion control and animation work was done on 35mm cameras. So Fries/Mitchell, Acme and Bell and Howell 35mm cameras for the most part, can go both ways. The early Arri 35mm cameras have the capabilities too, but not in every magazine. The Arri 435 is the most famous bi-directional 35mm camera, it's a basically "do everything" camera, but at a cost of course. There are others, but suffice to say with 16mm the choices are more limited.

In terms of exposure, yes I would just slightly under expose on each, maybe by a stop. As long as there isn't massive highlight blooming and you're shooting negative, you'll be fine.

Send me a DM, I can send you some samples.

I'm intrigued, forget my ignorance but, what other uses exist for rewinding film in a 435 apart from doing double exposures? Reverse?

Simon Wyss · September 8

The Bolex-H models from serial number 100401 on but the reverse claw has nothing to do with the frame line, in fact, you cannot shoot backwards because the shutter may uncover the aperture during film transport. That depends on a few degrees of angle of assembly.

Noé Cornago · September 8

11 hours ago, Dom Jaeger said:

I've had to rewind film in an SR many times doing steady tests. It's definitely not as easy or as controllable as with a Bolex or Beaulieu, but it can be done.

The safest way is to remove the film from the mag and rewind it in a darkroom with some rewinds.

You can do it with the film in the mag if you're not too worried about cinch marks by doing the following in a change bag or darkroom:

Unlatch the film from the hooks on the pressure plate. Open both doors of the mag and secure the take-up roller arm out of the way. Use your left hand to manually wind the film back onto the feed spool while your right hand lightly keeps the film in the plane of the take-up spool. Because the drive gear turns the take-up spindle at a faster rate than the sprockets feed through film, when you reverse the direction the film will slowly unravel on the take-up, so you need to keep it in place and before it unravels too much, periodically wind the take-up back tight while holding the drive gear with your other hand. It's a bit annoying but OK for shorter lengths like a steady test. For actual footage you want to use, like double exposure experiments, I would recommend removing the film and using rewinds.

The other issue with using SRs for double-exposure is that they don't have a frame counter to accurately gauge where you might want to overlap scenes, so you would need to estimate it from the footage counters.

The best camera for doing 16mm double exposures I think is the Bolex. In a properly maintained camera the frame counter is very accurate and counts up to 1000 frames, and the camera has a dedicated second claw for cleanly moving the film in reverse. It will not jam or damage perfs unless the camera is poorly calibrated or damaged. Bolexes were the animation and experimental film camera of choice for decades for a reason. But you could also use a Beaulieu, Cine Kodak Special, Arriflex 16 St or any other 16mm camera that has a frame counter and the ability to run in reverse or use a rewind crank. The frame counters on these cameras tend to reset much quicker than a Bolex though, only 100 frames on a Beaulieu or 40 on an Arri St for example.

Would it be easier to do on 30m daylight spools? I don't have access to rewinds sadly

Brandon Paterno · September 8

1 hour ago, Simon Wyss said:

The Bolex-H models from serial number 100401 on but the reverse claw has nothing to do with the frame line, in fact, you cannot shoot backwards because the shutter may uncover the aperture during film transport. That depends on a few degrees of angle of assembly.

id have to look at my negatives again, maybe I am misremembering whether or not the frame line is made less stable in reverse. ive done optical prints with the shutter open while the camera transports back on a traditional JK setup and never had any evidence of frame drag to indicate the shutter was exposing during transport (for crossover effects like forty eight cam forward, one proj forward one cam back for forty eight loops, blackout proj forty eight cam forward).

And I finished resetting a rex 3 a week or so ago and had no indication of the shutter exposing during transport UNLESS the shutter was intentionally put off. the difference in things being off, like you said, were literally a tooth or two.

1 hour ago, Noé Cornago said:

Would it be easier to do on 30m daylight spools? I don't have access to rewinds sadly

yeah, you could do this by hand. You could probably put two dowels into a little block of wood and spin the film over by hand or just hold the two spools.

I think the tiny Craigs rewinds are peak changing bag rewind faire -- they're like six inches tall. They were dirt cheap once but the prices are climbing.

re 435, rewinding is really good for doing stability tests? but ive heard that there's merit to rewinding outside of the camera in order to not warp the film perfs during the reverse movement. plus everything stays in line without needing to physically mark the film in any way. dunno

Tyler Purcell · September 8

3 hours ago, Noé Cornago said:

I'm intrigued, forget my ignorance but, what other uses exist for rewinding film in a 435 apart from doing double exposures? Reverse?

Now a days no reason, but during the film days if you wanted to contact print something, you'd need to run the camera the proper direction for the shot. So if you wanted to have a reverse shot, you'd have to capture it on set kinda. More for effect purposes than actual real usage. Arri just flexed their muscles with the 435 and basically offered everything outside of quiet running.