Shooting 16mm Bolex of a projected image.

[Nick Ray Harris]

Hi,

 

I plan to shoot a 16mm, B/W, silent film using a Bolex.

 

The script calls for moving images projected on a wall.

 

The plan is to shoot these images in video, and project them with a digital projector. Then shoot that in the scene with the Bolex.

 

Will this work? And is there any advice you can offer?

 

My initial concern is the frame rate of the video shot and then projected, as well as the projector being bright enough to come up on the 16mm.

 

Thanks,

 

Nick Ray Harris

[Phil Rhodes]

The filmability of the projected image depends on the lamp and modulator technology the projector uses.

 

LCD projectors tend to be quite shootable, because the LCD element doesn't change state very fast. Sometimes they shimmer slightly, but it's rarely objectionable and you should be able to figure this out by viewing the projected image through the 16mm camera dry-running.

 

DLP projectors are a serious problem, since they change state much more quickly and in fact rely on very high speed state changes to produce variable brightness in a pixel. Worse, single-chip DLPs (which is effectively most of them that you'll find in a domestic use situation, or anything that doesn't specifically shout about being 3-chip DLP) use a spinning colour filter wheel. With these you can end up with flicker in both brightness and colour, though again, it should be visible in a dry-run camera.

 

I assume this bolex has no ability to sync to an external source or adjust its timing to suit; even if it could, however, a lot of current projectors are locked to inconvenient rates such as 60Hz, and will convert inputs of any rate to 60Hz regardless of what you feed it. This would force your hand with regard to frame rates. If the camera has an adjustable shutter angle, you could look into safe angles for whatever rate the projector runs at, which is very likely to be eith 60 or 72Hz (72 being 3 times 24 and therefore useful, but rare).

 

If, being a bolex, it isn't crystal sync, isn't adjustable, and can't change its shutter angle, you have little option but to find an LCD projector and live with whatever you can get.

 

You have an additional concern, too - the colour balance of the projected image. Almost all modern video projectors use some sort of discharge light source which is probably nearer to daylight than tungsten, but almost anything can and will be done in the projector's video electronics to adjust the output. I would suggest that you shoot a test (at least, shoot a stills test using film of the same colour balance as your 16mm) and determine what, if any, filtration you might want to put on the projector. For video you almost always end up gelling significantly orange and the projected image tends to look terribly muddy and brown to the eye, but OK on video. I don't know how film will react, but it may be somewhat similar. Sometimes you can adjust colorimitery controls on the projector (I've done it many times on plasma screens), or you may need to put a filter in front of the projector's lens, or light accordingly and filter at the camera. In either case this will cost you projector output.

 

As to brightness, all you can do is meter it (with any correction in place, of course).

 

P