You are viewing an obsolete version of the DU website which is no longer supported by the Administrators. Visit The New DU.
Democratic Underground Latest Greatest Lobby Journals Search Options Help Login
Google

Reply #79: OK. Sorry for the delay... [View All]

Printer-friendly format Printer-friendly format
Printer-friendly format Email this thread to a friend
Printer-friendly format Bookmark this thread
This topic is archived.
Home » Discuss » Archives » General Discussion (1/22-2007 thru 12/14/2010) Donate to DU
anigbrowl Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Jul-08-08 11:18 PM
Response to Reply #46
79. OK. Sorry for the delay...
Edited on Tue Jul-08-08 11:19 PM by anigbrowl
I had other business most of the day.

To be specific, this is just going to be about the flashes of light on the single frames of the lady's film. I can't go through and address every last thing in the video, I don't have time or the original material. So this is just the obvious thing (to me anyway).

OK, when you look at these pictures you see images like this:


This is just some random picture I pulled from Flickr. Forget the scenery, look at the pattern of the light trails. I kept noticing similar patterns over and over as I watched the lady's film. You see how the streaks of light all have the same shape? That's an indication that the camera was moving during the taking of the photo. Over and over as I watched the video, I kept noticing these repeated shapes. There's be fairly static pictures of 3 or 4 lights, then a frame with 3 or 4 streaks that had similar shapes. I'd keep trying to look at these pictures non-judgmentally, and my brain would just keep saying 'but that's camera shake. You've seen it a million times.'

OK - but there were a production designer, a visual effects guy, and a cinematographer who all swore there was no way she could have created this effect with computers or developing equipment. Quite true. What I found strange was that nobody considered the possibility that it arises out of a fault in the camera.

Now, I know something about film (aka movie) cameras (video too, but I am nostalgic about film cameras). I've shot with 8mm cameras, 16mm cameras, and 35mm cameras. I'm not a cinematographer, but I do work in the film world and I've owned 8mm and 16mm cameras, and am able to perform basic maintenance and repairs on them. So I sometimes buy a broken camera on eBay if I am pretty sue what's wrong with it, fix it, and maybe make a few bucks. Or not. I just like fixing things, and I like the feel of shooting film although it's too expensive for me to do regularly.

Well, what I see here is called a 'registration problem'. The lady is shooting with an 8mm camera. Hard to say which model, but most such cameras shoot film that is called 'super 8'. It has holes just down one side of the film stock, and you get a bigger (=better) picture by exposing the other side of the film (where there are no holes) than just a square in the center.




Got the idea? OK, so now you know what sort of film we're talking about. Incidentally, it does still get used in Hollywood sometimes - for flashback scenes to give an old feel, or occasionally in crash cams, where you put a cheapish camera in a car and then crash it (or suchlike). If it's only 1/2 a second the audience won't necessarily notice the quality issue.

Anyway, the way a film camera works is there's a motor (electric or sometimes wind-up) turning gears which open the shutter and move the film along, sometimes using pins or sometimes a clamp mechanism. And what I think is happening in these single-frame 'flash' pictures is that the mechanism is momentarily jamming, leaving the shutter open and letting the film be over-exposed. It could be for a very short time, like 1/9th, 1/6th or 1/3 of a second (I choose these numbers because Super 8 is normally shot at 18 frames per second, as is mentioned in the film).

The film has all the qualities of being over exposed (when the video stops on a frame long enough to let you look), and the repeating patterns described above would also be consistent with the momentary shake while the shutter is open for too long. The streaks in some other examples which look like lines of dashes would be consistent with a light source flashing while moving - for example, some lights on planes or the indicator lamp on a moving car.

Please note, I'm saying that that's the sort of image you'd get if you over-exposed a picture of such a light source at night. I don't know enough about this lady's house or even where it is to make any guesses about what the particular lights are, although I did see some blinking red lights on one segment that I'm pretty sure are hazard lights on an industrial or communications tower designed to warn pilots about the structure.

My guess is that the specific thing with the camera is that it has a broken gear tooth which causes the shutter mechanism to jam open briefly, and not too often. Bear in mind that gears are designed by engineers to use numbers of teeth which will spread wear evenly over the gear, so a damaged tooth on a gear does not mean that such a shutter error would occur every second or even regularly. Camera film is not tensioned tightly inside a movie camera (as it would break easily) so the problem could be quite intermittent. It might only occur when the film tension is above or below a certain threshold, or under a variety of other conditions. Without knowing which exact film camera she is using I can't make more specific guesses, but you've ever looked at a clockwork mechanism or even an old film-winding camera you can get an idea of what I'm referring to.

There are two ways to test this: one is simply to give the lady a different camera. They still make super-8 cameras, and you can get used ones very cheaply on eBay. If the flash frames go away with a different camera, that's a strong clue. The second way is to examine the patterns of light which I say are caused by camera shake.


New, very expensive

Old, cheap

This is even easier: loan the lady a tripod and a cable release (so you can keep filming without pressing down the button on the front of the camera dn possibly shaking it. Most cameras have these, they're a $10 part). Leave it set up on the deck or wherever she usually films, Or even use one of the small portable ones which can be easily attached and are very lightweight. If she hears the noise and gets the idea to film, she just points the camera at the lights, starts it, and lets the camera sit still on the tripod. Wiggly lines go away = proof wiggles are caused by movement due to handheld filming.

You could them measure the size of any light blooms on the film frame, deduce (by looking at the films response curve - example below) how long the overexposure was, and from there you should be able to predict with some accuracy about where the gearing fault is (if it is a gear, as opposed to a spring or some other component). I don't want to destroy the old lady's camera looking for a mechanical fault since it probably has sentimental value for her.


Printer Friendly | Permalink |  | Top
 

Home » Discuss » Archives » General Discussion (1/22-2007 thru 12/14/2010) Donate to DU

Powered by DCForum+ Version 1.1 Copyright 1997-2002 DCScripts.com
Software has been extensively modified by the DU administrators


Important Notices: By participating on this discussion board, visitors agree to abide by the rules outlined on our Rules page. Messages posted on the Democratic Underground Discussion Forums are the opinions of the individuals who post them, and do not necessarily represent the opinions of Democratic Underground, LLC.

Home  |  Discussion Forums  |  Journals |  Store  |  Donate

About DU  |  Contact Us  |  Privacy Policy

Got a message for Democratic Underground? Click here to send us a message.

© 2001 - 2011 Democratic Underground, LLC