Color Paper Top Emulson Layer

Photo Engineer · Dec 13, 2012

From someone who has printed since before 1960, I can say that there are some problems with the process, but if you choose to ignore me that is OK. Look at your two posted prints for Dmax and Dmin. They are totally different. Stop. Think about this!

That is all I ask.

PE

RedSun · Dec 13, 2012

PE, thx for the help.

The two test strips are from different days. From the very beginning, it took me like 10 test strips to calibrate the ColorStar. Then for each new day, I calibrate the Colorstar again. And it takes about 3 test strips to get it right subsequent days.

The test strips are supposed to be different, reflecting variations of the chemicals and any other changes (lamp, paper, etc). They can also tell me the changes of the chemicals.

Sry that I did not make it clear from the beginning.

RedSun · Dec 22, 2012

I got some time to get into darkroom again. This time, I added fresh water rinses after each stage, developer, blix and RA-rinse. With this, the blue tint I got from last time is totally gone. So clearly that blue/cyan color coating is not part of the color layer, but just some top coating for other optical purpose.

The water rinsing does add about 2 more minutes processing time. But I figure this is helpful with the good photo quality and good for chemicals too. I used to do a complete rinse with final prints, not with test strips...

AgX · Dec 22, 2012

RedSun said:
This time, I added fresh water rinses after each stage, developer, blix and RA-rinse. With this, the blue tint I got from last time is totally gone. So clearly that blue/cyan color coating is not part of the color layer, but just some top coating for other optical purpose.

From the fact that some dye vanishes you can't deduce in which layer it sat. Even if you used just plain water.

RedSun · Dec 22, 2012

I'm not going to argue anymore with what layer that blue/cyan color is for. If someone really knows what the Fuji CA blue/cyan layer is for, let me know. Or we just move on.

Prof_Pixel · Dec 22, 2012

AgX said:
From the fact that some dye vanishes you can't deduce in which layer it sat. Even if you used just plain water.

OzJohn · Dec 22, 2012

Over the years that I printed colour, I noticed that nearly every paper had a tint that ranged through shades of blue, purple or pink and that this colour was cleared, lightened, dissolved - whatever - if water was applied to the undeveloped paper. I have no real idea what the dye does or where it is located in the layer stack but I suppose a reasonable deduction (at least by someone more interested in making good colour prints than how the material is made) would be that it modifies the sensitivity of one or more layers.

Apart from being in awe of the sophisticated chemistry and precision engineering that goes into making coated photographic products, I care as much about their internal structure as I do about how Intel have engineered the microprocessor chip in my computer. Both classes of product work superbly for my purposes and that is what I pay for.

Photo Engineer · Dec 22, 2012

Colored dye is added to each batch of color paper for two reasons. One is to adjust the speed to an optimum and constant value, and the other is to reduce internal light reflections that decrease sharpness.

PE

Prof_Pixel · Dec 22, 2012

Photo Engineer said:
Colored dye is added to each batch of color paper for two reasons. One is to adjust the speed to an optimum and constant value, and the other is to reduce internal light reflections that decrease sharpness.

PE

Sigh...

Photo Engineer · Dec 22, 2012

Yeah! Sigh.

ME Super · Dec 23, 2012

All is not lost, Ron. I learned something!

Color Paper Top Emulson Layer

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