P3D Re: Stereophotographing anaglyphs

[PK6811S@xxxxxxxxxxxxxx]

>>   1)	cardboarding - I think because of the limited separation of the Q-dos
>>system, you get apparent depth between figures and background, for example,
>>but individual people, etc. look somewhat flat.

Right.  Cardboarding in single-lens recording is not different from
cardboarding in two-lens recording, but because of the smaller stereo
separation is more likely.

>One of the problems with the Q-dos was that it's internal filter had a clear
>center stripe. This stripe created a clear separation between left and right
>images. It therefore photographed a single object as though it were two
>independent objects, much like a dual lens system.  It was this separation
>in the Q-dos system that caused card boarding.

Have to disagree here.  Cardboarding is a function of stereo separation,
resolution of the recorder, and acuity of the observer.  Greater separation
reduces cardboarding and increases apparent depth.

>So, do you think a home-made red/cyan lens might work better then the
>Q-dos?  I haven't seen any results for comparison, but I know a few people
>on the list made some a while back.  How were they?

I posted some theory and experimental results a year or two ago, they
should be in the archives.  Where are those archives anyway?  I tried
some old links and searched from Altavista, but all the BOBCAT links
can't be found.

A simple red/cyan test can be made by putting the filters in front
of your lens.  Better if you can open a lens up and put them over
the diaphram.  A lens with a large pupil will get a better stereo
effect - more average separation between sides.  Hold the lens up to
a large light source (sky, wall) and look through the front to see
how large the pupil appears.  

I found that a 135mm f2.8 worked pretty well, using closeup tubes
allows one to get up close and personal with small objects/insects/etc.
Look around for an old screw mount lens and an adapter for your camera.
I had good luck with these, usually the front lens can be worked out
to expose the diaphram and a simple left-right mask can be made from
stiff, dark paper or old floppy disk jackets.  Just tape/glue the
filters over the mask, and stick it in place in the lens with small
dots of contact cement.

I put together a lengthy compilation of my earlier postings, if anyone
wants it just email me, I've bored the list with it once already.

Paul Kline
pk6811s@xxxxxxxxxxxxxx


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