Re: colors for colorizing digital negatives

Katharine,

I did a similar experiment for another process but I over exposed in the
hope it would increase the difference between the triangles that are
"blocking" UV. By doing this I also got 5-6 triangles that where better then
others and one that definitly was opaque to UV in my particular situation.
It's the fourth from the right on bottom row (green on the right, red on the
left but I don't recall if I put the neg face up or down). I also notice
this triangle wasn't the most opaque visually and by far.

There are several layers of translations between what you see on your
screen, what's in the file and what gets printed in the end. In the case of
gum and probably of most other process if not all of them, there is another
important factor to consider, I think it's is called the gamut or if you
prefer the range of colors you can reproduce with the process used. In all
case, this gamut is only a relatively small subset of what can be produce by
your monitor which is also a subset of all theorical color possible. In
other words WYSIWYG is a day dream when you try to get something out of the
box (computer).

All this to say that adding color to your negs is only the tip of the tip of
the top most ice crystal on the iceberg. Ideally one should aim for
linearity between what is seen on the screen and what gets printed in the
end. Here I assume that one likes (loves) what is viewed on the screen and
would like to see the same qualities on the print but I guess it would be
very difficult if not impossible to realise. One possible avenue I would
consider is to create a color space that match what is possible with the
printing process involved, otherwise it would be quite a challenge to
interprete what you see on the screen into what will result from all these
translations from file to print. I'm not saying it's impossible but I would
say only a few people could achieve this level of visualisation and it would
take a long longgg time to get there.

There is still a problem with what I just said. If it's possible to
constraint the monitor to show only what is possible on the final print,
there would still be many translations involved to get what's on the screen
to paper. Finding the color that results in Dmin on the print is just a tiny
step on this road.

I wonder if something as been done along this line of thought?

Regards,
Yves

PS Nothing personal here, I'm just thinking aloud.

----- Original Message -----
From: "Katharine Thayer" <kthayer@pacifier.com>
To: "alt photo" <alt-photo-process-l@sask.usask.ca>
Sent: Friday, March 24, 2006 11:15 AM
Subject: colors for colorizing digital negatives

> Hi All,
> I'm so glad to have a printer (Epson 1280) that will allow me to
> print negatives on transparencies again. My 1280 prints great
> negatives by simply choosing "color inks" and "inkjet transparencies"
> to print a black negative that's dry almost as soon as it comes out
> of the printer. The negative looks fairly thin when you hold it up to
> the light, but it prints gum beautifully, and I don't see any reason
> not to just keep doing this.
>
> But last fall when Clay posted his ternary method for choosing a
> color to use for colorizing, I was intrigued, and the other day I
> downloaded the triangle (thanks, Clay!) and printed it on Pictorico
> (by the above method) and printed that (twice) on gum, just out of
> curiosity.
>
> I found that six of the seven triangles that blocked radiation
> completely were in the red corner of the larger triangle: (R: 255,
> G: 0, B: 0) (R 190, G 0, B 0) (R190, G 0, B 64) (R 190, G 64, B 0)
> (R 128 B 64 G 0) (R 128, G 128, B 0). The other one was (R 64, G
> 128, B 0). The other triangles in the red corner, and the other
> triangles in the green corner, printed with various fairly light
> tones. The triangles in the blue corner printed with heavy tone, with
> one exception they printed as dark as the tone in the border outside
> the triangle; in other words, for almost all mixtures containing more
> than B: 64, the ink didn't add anything to the Pictorico in terms of
> blocking radiation.
>
> This is interesting to me in that when I tried printing colorized
> negatives with my old printer (Photo Stylus EX) I didn't find that
> colorizing with red-orange worked well at blocking radiation, and
> in fact I just got rectangles of solidified gum, no image, by either
> of Dan's colorizing methods. It's also interesting given that I
> thought I'd been reading (this could be wrong, because I wasn't
> paying too much attention to those discussions) that people were
> finding a green or blue-green color to be best. But maybe that wasn't
> for gum. Or maybe it was for inkjet printers that use pigmented inks
> rather than traditional inks.
>
> I do understand, as other folks have cautioned, that one shouldn't
> make much of the color, because how well an ink blocks light probably
> has more to do with other properties of the ink than with the color
> per se, and besides it's probably one of the many issues with gum
> that are best resolved individually since each printer will find a
> different color that works, depending on the characteristics of the
> printer, and it's what works that counts. But I'm stlll curious.
>
> I don't have a transmission densitometer, but just looking at the
> negative against the light and laying it over newspaper text, I can't
> see any noticeable difference in transparency between the different
> colors (my hypothesis would have been that the blue ink is more
> transparent than the others). And when I scanned the negative back in
> as film and looked at the colors as printed (as opposed to the colors
> in the original file) I didn't find that the blues were lighter than
> the other colors, although I did find that the blues were in
> general less saturated (many of the colors in the original file were
> out of printing gamut, but the printer desaturated the blues more
> than it desaturated the other colors to bring them into the printer
> gamut).
>
>
> Katharine
>
>
Received on Fri Mar 24 12:36:56 2006