RE: Ask Dr. T, part II - Realism & Anaglyph

[P3D Shelley, Dan <dshelley@xxxxxxxx>]

Thanks Dr. T for the response to the list. I have been anxiously 
awaiting it... =) However, we did seem to have differing expectations 
from this view exchange.

>My statement that slides viewed in a good viewer 
>are more realistic than other stereo formats, was 
>challenged by Dan Shelley.  Dan was kind enough 
>to send one of his anaglyph images that he considers 
>an example of realistic stereo photography.  

To clarify: I had thought the reason I sent the view out was to show 
what I thought was a good example of an anaglyph vs. the many, many 
schlocky anaglyphs that exist ... to show that good anaglyphs, that 
show depth, and represent a scene correctly in 3D,  can be made. I do 
not remember this being a "challenge" between formats. That would be a 
silly argument as any full color slide pair will always look better in 
a slide viewer than any anaglyph will with anaglyph glasses. 

Also, that image is a major step towards completing my pet "project" 
which is to create a book of anaglyph images of the Pike's Peak region 
in Colorado, similar to Owen Pharis's "Las Vegas in 3-D" book. I wanted 
to know if the image was OK for that environment.

>I moved around the house trying to find the 
>optimum lighting conditions for viewing this 
>image. In the process I realized that good 
>light is important for viewing anaglyphs and 
>I found an overhead long fluorescent 
>light to be the best.

I too have found that the more light you have on an anaglyph image  
when viewing it the better. Also, it helps to have the anaglyph glasses 
on for a few minutes  before you even try to look at the image. I guess 
this helps you brain accept the colors in front of each eye as "normal" 
so taht when you finally look at the image, you only see a 3D grayscale 
image. I have found that this adjustment period does help with some 
"ghosting" in anaglyph images.

>...BUT, is that enough to say it is "realistic"?  
>Not in my opinion.  

Again, I would have to agree. My intent was never intended to be 
"realistic" as you describe it. I did intend to present a 3D 
representation of the "real" scene in a format that can be cost 
effectively reproduced in a book.

>I am not saying that anaglyph is not a valid 
>or it is an inferior stereo format.  In many cases 
>it is the most practical format to use.  And Dan's 
>anaglyph is certainly a good piece of work.  

Many thanks. I value this comment. 

I too think that the image is a good one, especially when you consider 
that the 8x10 was printed from a negative created from a computer 
manipulated pair of Photo-CD images. The picture you were looking at 
was completely digital. Did you know that? Also, I only used a machine 
at  a local processor to create the print myself (in 5 minutes), so the 
machine made many of the processing decisions/choices for me. Had a 
technician developed the image by hand, it might even be better(?)...

>But, in my mind, the anaglyph presentation 
>is inferior to stereo slide presentation, provided 
>that a choice exists.

The key there is "provided that a choice exists". In printed materials, 
the anaglyph is the best way to reproduce a stereographic image. 
Projection is not even an option.

>Another problem is finding the proper combination 
>of colors and glasses.  The anaglyph glasses that 
>Dan supplied showed considerable ghosting (this 
>is very similar to ghosting seen in projection of 
>slides through weak polarizers).  Joel put another 
>pair of glasses in the package and this pair eliminated 
>the ghosting.

I too noticed some color discrepancy with this particular image. A 
large part of that is due to the machine I used to develop the print. 
Again, had a technician been working with me, attempting to match spec 
colors, I think that a perfect match could be attained. (This is 
probably going to be the most difficult part of the book making 
process... Although the guys in Denver who burned the new negative for 
me were very excited about working on this unusual project.) I really 
do look forward to seeing Joel's glasses, and how they affect the 
image.

Thanks again Dr. T for the post.

Dan Shelley
dshelley@xxxxxxxx


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