Re: How not to show a 3D film...let me count the ways

[P3D <klein@xxxxxxxxxxxxxxxxx>]

On  8 Sep 97 at 18:41, P3D Robert Cruickshank wrote:

> The other night I was subjected to a screening of Flesh For Frankenstein
> (aka Andy Wharhol's Frankenstein), and I must say I can really sympathize
> with audiences in the 50's whe were victims of bad projection. (I can't
> totally fault the Bloor Cinema- I saw Dial M for Murder and House of Wax,
> and both were fine (aside from some ghosting) Something was up with
> Frankenstein , though- most of the film was actully shown flat, but
> "behind a window"

I do have a copy of Andy Warhol's Frankenstein myself - and all of the 
movie is definitely in 3D - not just with a few 3D-sections like "The 
Mask".

> there was a little bit of depth in motion shots, which
> was probably due to the of the left and right frames being different
> enough (due to the motion) to show some depth *if* the camera was moving
> the right way. Or maybe it was wishful thinking.

This could have been the Pulfrich-effect, especially since you mention 
below that one frame was darker than the other.

> There was a collective
> gasp of surprise when, lo and behold, the film jumped into actual stereo,
> for one reel- or as close as it could get- the frames were badly
> misaligned vertically,

The Stereo Projection lens actually has a few adjustments: you can rotate 
the whole lens in order to adjust for vertical misalignment, and then 
there's a separate adjustment for convergence and focus (just one side). 
So this is basically what you're doing before showing a movie:

a) insert the alignment film-loop. Frankenstein requires an alignment-loop 
with .366" vertical distance between left-eye and right-eye picture.

b) adjust focus. Only if left-eye and right-eye picture are unevenly 
sharp, adjust focus on the lens (usually a one-time setting).

c) rotate the lens slowly so the two horizontal lines of the "+" marks for 
each eye (on the alignment-loop) are on the same height (vertically).

d) adjust convergence to the two vertical lines of the "+" marks (in the 
alignment loop) superimpose on the screen. You should now see only one "+" 
directly on the screen.

e) stop projector and remove alignment-loop. Replace with actual 3D-Movie.

>  the plarizers were out of alignment and one frame
> was really dark, but if you held your head just right...

Sounds like bad polarizers ... Or the lens was really badly adjusted. But 
it could also be a bad screen or bad glasses.

>  then the film
> stoped the lighs came on for a while, then we saw some leader, then back
> to the flat version, then some more leader, the lights came on
> again...etc. Maybe twenty minutes were actually in stereo.

Ouch!

> The scene with
> bats flying into the camera was flat, as was the infamous "liver on a
> stick" scene.

Too bad! There are really a number of great 3D-scenes. Apart from the two 
mentioned above, there's also a good one where Otto cuts off the Serbian's 
head ...

> At one point I actully saw someone pull out a pair of
> anaglyph glasses to see if they made things better!  I was one of the few
> people who actually bothered to get my money refunded- I think a lot of
> people were convinced that 3d really *does* mean headaches and eyestrain.
> (My head sure hurt, but then, I had just watched House of Wax sitting way
> too close. These films make a good double bill if you want to have a
> "gee, I've seen that head before" theme, BTW)
> 
> I imagine the problems were caused by the frame sequence getting out of
> whack after a splice- how exactly do single strip systems work, anyway?
> Apperently this print was Paul Morrisey's (the director) personal copy- I
> wonder if he's watched it lately.

Many problems _can_ be caused by a bad splice - but even then the 
projectionist only has to adjust the movie by half a frame (can be done 
withing two seconds) and you're back in business. I also had one bad 
splice in one of my movies - but I simply removed the from half from the 
movie.

To see a drawing of a lens, and a few frames from actual stereo movies, 
just visit my web-page at

	http://www.stereoscopy.com/3d-movie-magic

3D-Movies can be great if the projectionist knows what he's doing.
Alexander Klein
3D-Magazin, Editor (http://www.stereoscopy.com/3d-magazin)
Webmaster: http://www.stereoscopy.com


------------------------------