[photo-3d] Re: Bogen slide bar

["Dr. George A. Themelis" <drt-3d@xxxxxxx>]

I wrote this reply to a question regarding how
useful the slide bar is, and decided to post it
here for comments/discussion.  The question was:

>I have discovered 3-D photography in the last month, and am gradually 
>learning the how-to's and "who-has". I've been taking my digital 
>cha-cha's hand held, and they seem to work fine. Will the results be 
>much better with a slide bar, and justify the burden of the tripod?

===

Hello Brian and welcome to the wonderful world of
stereo photography!

Right now I am working on a Tutorial article on
stereo with a single camera for our stereo club
newsletter which I also edit.  In the January
issue that just came out, I organized single-camera
stereos in the following groups:

1. Stereo (usually hyperstereo) with a slide bar
2. Hand-held normal stereo
3. Hand-held hyperstereo
4. Stereo from a moving platform
5. Stereo of a moving object from a fixed platform

The slide bar is useful for taking close-ups of
small objects (group 1).  It is also useful for
normal stereos (group 2) if you want to have perfectly 
aligned stereo pairs.  

You could skip the slide bar for normal photography
and do it hand-held.  While it is difficult to keep the
two shots aligned, this improves with practice.

Whether "perfect" alignment is important or not, the 
answer depends on the viewing method.  If you take
slides and view them in a good viewer or projection
then alignment is very important.  For stereo prints
or computer stereos viewed at lower magnification
alignment is less important.

Does it justify the burden of the tripod?  Again, it
depends.  For close ups, a tripod and slide bar is
an absolutely "must have/do".

Overall, a slide bar is a good tool to have around.

Regards,

George Themelis