slitscan conversion of Super 8

[Matthias Dautel]

So, I´m new to Super 8 and want to modify my old camera ( a Revue CX 300). As I understood is the film moving while the aperture is closed, then it opens up, exposes and closes again and moves to the next Picture. What I want to do is to modify the camera, that the aperture is open, while the film moves and closes when the film stops. There is also an small slit directly in front of the film- In Photography you get pictures like this when you move ( with a handcrank) the film behind a small slit :

 

http://www.cy-dee.com/index.php?/ongoing/slitscan/

 

Anyone an idea, if this is possible to do with a super 8 cmaera?

 

thanks a lot!

 

Cy

[Martin Baumgarten]

Matthias, the concept you are wishing to use from the still format usage, is not usable in practical terms with Super 8mm (or any motion picture format). This is because in creating a still image via a slit-scanning method...variations of density still create an image across the single large frame from which a photo will be made. In movie film usage, there are 18 frames per second (or 24), and thus if the film was just moving past the gate without an intermittant movement to stop the film for that fraction of a second to achieve the individual frame image.........the results are just streaks of light, without any real detail to them. Sorry, maybe someone can add something to this concept.

[Dom Jaeger]

Hi Matthias,

 

what effect are you hoping to achieve? Have you thought about how to translate those sorts of still images into moving pictures?

 

As Martin said, exposing cine film as it is being transported just results in smears of light. Even if you masked the gate down to a slit, you would just get very fast exposures of the same slitted field of view smeared across the frame.

 

People have experimented with setting the shutter slightly out of synch, which results in a viewable image with the highlights streaking vertically.

 

What might be interesting, and closer to the effect of the photos you referred to, is to use a camera with a variable shutter, set to a very narrow angle, and film at a slow frame rate. The narrow shutter angle would work like a slit passing across the film, and at slow filming speeds any subject motion would cause deformations. Played back at normal speed, of course, everything would be sped up, and very jerky, and the individual frame deformations would probably all blur together into an unwatchable mess.. but hey this is art right? B)

[Matthias Dautel]

Thanks for your answers. Maybe I´m totally wrong :( - but maybe it is possible. I opend the revue super 8 camera yesterday. There is the transportingsystem and a half circle out of thin metall, covering the light to go to the film while it is moving and opens up, when the one picture is exposing for a fraction of a second. Now I tried to change the position of the half circle for 180 Degrees- now the lightpath is open, when the film is in transport and closed, when the film is not moving. So- when I now mask the gate down to a slit ( 90 degrees to the direction the film is moving), should every single frame get exposed through the slit while the film is moving past the slit. Then no exposure while the film is not movin and then the next frame ...Of course I have to hold the camera also 90 degrees rotatet... Shoud be a row of individual "slitscan" pictures- but of course I don´t know if this produces somethin in playback? Any idea about this ...? Or Am I on the very wrong way ;-)

 

@ Dom

The effect I want to achiev is that moving action is vissible and all the not moving thing are only smears- like in the photo... and yes- it is art ;-)

[Nicholas Kovats]

Matthias,

 

Motion picture slitscans are a fascinating topic.

 

The penultimate example is Douglas Trumbull's work in 2001. I found this elemental explanation on how the effect was achieved, i.e. http://www.underview.com/howscan.html.

 

What I suspect you are attempting is a variation in solidity with moving objects. Check out the live band sequences in my film "Silly Billy" whereby each frame was held open for approximately 3 seconds. The variable movement of the subjects produced an interesting Francis Bacon screaming pope effect whereas

 

1. if the subject stood still they were recorded "solid",

2. if the subject moved they were recorded as a "wispy trail" but connected to the solid bits.

 

 

On average there were 3x solid moments interconnected by wispy trails in one single manual 3 second exposure. Now my "slitscan" was the standard Super 8 squarish frame (1:1:33) open for 3 seconds.

 

I suspect if you were to mask the the standard Super 8 frame with a slit you will need to increase your exposure time per slit/frame. Now will the light spill or bleed over the edges of the slit as the exposure time varies? What if the slit was moved during filming? Do different slit shapes produce different effects? Can you achieve a smooth effect when locking off the camera on a tripod? What happens when you handhold the camera while circling your subjects 360 degrees?

 

Good luck with your experiments!

[Dom Jaeger]

Hey Nicholas,

you got some lovely effects in that movie. Some of the band shots did remind me of Francis Bacon paintings.

 

Matthias,

as I see it, the only way you'll get anything vaguely recognizable is if the subject is moving at the same speed as the film. Is that the idea? You could try and work out how fast the film is being transported (at 18 fps, one frame = 4mm in maybe 1/40 sec, so 16 cm per second?) and have the subjects move at that speed past the tilted camera. I don't know how it'll play back as moving pictures, but you might get some interesting individual frames. Alternatively, you could move the camera at that speed, in the opposite direction of the film movement, perhaps circling a subject as Nicholas suggested, or from a moving car window?

 

The toughest bit will be judging your exposures. They'll be quite fast, for a 1mm wide slit maybe 1/160 sec? If the film transport phase is quicker than the open shutter period, or your reversed timing is a bit out, you'll get patches of higher density at regular intervals, where the film is stopped but the shutter is still open.

 

Should be fun! Definitely let us know how it goes.

[Matthias Dautel]

Thanks, yeah - I´m on my way ;-)

Think I can expose one film next week- then let it develop and scan somewhere (is this still possible...?) and we will see.

 

@ Nicholas - fantastic footage, very different from what I hope to achieve- but who knows. I like the "no shutter" look definitely.

 

@ Dom - yes I think it will be around 1/150s- maybe near to 1/200s... I need a very sunny day :-)

If the objekt is moving with the same speed ( really fast...) it is perfect- if it is moving slower it will deform and get very wide- maybe also nice.

[Nicholas Kovats]

Another suggestion might be to mount the proposed slits externally.

 

Having the slit sitting at the frame might produce soft edges slit side dependent on your far end plane of focus. Trumball had the slit resting in the same focal plane as the artwork. A suggestion might be to mount a slit in a threaded C-Mount holder, i.e.

 

http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productid=1619

 

And I believe these precision pinhole/slits will fit the above holder, i.e.

 

http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productid=1619

 

But then again image sharpness is probably not your end criteria as it was in 2001. :)

[Chris Millar]

Its totally doable ...

 

Here is some slit scan stuff I've played with:

 

 

its not analog and not created at the point of capture - but I get what you're keen to do ...

 

Just remove the pulldown and let the take up do the work - it'll be tricky getting a slit thin enough so that you get the effect in a high temporal resolution and get a correct exposure and of course, it'll be a very looooong still - watching it in a projector wont be very much more than a pseudo random kinda mess, unless of course you choose and plan what you're capturing very carefully (could be interesting!)