On Sep 3, 2009, at 18:14 , Graydon wrote:
On Thu, Sep 03, 2009 at 09:04:15PM -0400, Scott Loveless scripsit:
On 9/3/09, Graydon <[email protected]> wrote:
On Thu, Sep 03, 2009 at 08:54:58PM -0400, Desjardins, Steve
scripsit:
I didn't realize they could do color that well back then.
Arguably, they couldn't; it was a three-sequential-negatives
process,
and really tough to put back together chemically to get a colour
image.
If I'm following the various articles correctly, many of the
images now
available were not available at the time; digital recombination is
much
easier and the Library of Congress had all the possible ones done.
I thought it was 3 monochrome positives projected through 3 separate
filters. Red, green and blue, or something like that. And that
getting the projectors set up properly was the hard part. Or maybe
I'm smoking crack again.
That was the display technique, but (and I could be out to lunch
on this) I understood that there was some mechanism to get a print,
too.
I might be very wrong about that.
I think they were only for projection, using a projector very similar
to the later 3-color glass plate cameras that took 4x5 film, but used
one lens. I had one of the 4x5 cameras for several years, but the
partially silvered mirrors were cracked, broken and missing parts, and
the interior of the cast body was thick with white corrosion. It took
film packs, and had three grafloc like backs, with one having a
focusing screen. I sold it for $200 and a lens. Here is a similar unit:
http://www.vintagephoto.tv/devin_img.shtml and
http://www.geh.org/fm/mees/htmlsrc/
mJ83000001_ful.html#topofimage and
http://www.tonysleep.co.uk/blog/eat-your-heart-out-epson
Here is the link to how the LoC handled the process to get printable
negs.
http://www.loc.gov/exhibits/empire/making.html
And about how they were viewed, the LoC says:
We know that Prokudin-Gorskii intended his photographic images to be
viewed in color because he developed an ingenious photographic
technique in order for these images to be captured in black and white
on glass plate negatives, using red, green and blue filters. He then
presented these images in color in slide lectures using a light-
projection system [right] involving the same three filters.
There is a drawing of the projector(s) used, basically a stack of
three lantern projectors. And I found a camera similar to what they
think he used to make the exposures.
http://camerafinder.com/cpg/displayimage.php?album=3&pos=9
When the one I had was made, they had projectors that used a reverse
light path to project colored light through the three negatives and
out one lens through a series of semi-silvered mirrors..
Joseph McAllister
[email protected]
http://gallery.me.com/jomac
http://web.me.com/jomac/show.me/Blog/Blog.html
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