Effect on color when shading/burning in.

[J.Leslie]

Does anyone have any ideas or solutions to the color shift that happens when one area of a print is either shaded/dodged or burned in? Should I be making a colored shade? Print in two steps with different color adjustments? Help. please.

 

[Ed Sukach]

Does anyone have any ideas or solutions to the color shift that happens when one area of a print is either shaded/dodged or burned in? Should I be making a colored shade? Print in two steps with different color adjustments? Help. please.

Printing exposure will have a decided effect on the appearance of color balance in a print, although there is less of a color "shift" than there appears to be. Certainly, one could "split print" using different dichro color filtration, but I haven't done that ... I'll have to try it ... all though I can imagine a complicated process requiring a lot of experimentation and practice.

Hmmm... colored dodging tools... filters on a stick. Could work - although I have an idea that they would be hard to control and tricky.

One thing that makes dodging and burning more difficult in color is the sensitivity of color papers. Usually there are shorter exposure times than with black and white - when the f/stop is decreased to allow more time, the image is very dim.

 

[J.Leslie]

Yes, Ed, I think you re-stated my frustration quite well. My concern with a colored or filter dodger is that filters still let the image through somewhat and I'm afraid that the waving about in front of the image will let some of the image through distorted. I'll try it though and let you know.

I tried tri color printing last night to see if I could better control which colors are dodged/burned in. It was better but time consuming. I have 324 images to resolve this for, so the time cost will be frustrating with tri color. Again, something like the tri tone separation using hard line negatives that don millikan mentions in another thread might be adaptable to this problem, but to do so for so many images would be nuts.

Thanks so much for the quick response.

 

[Thilo Schmid]

J., color shifts may result from short exposures. Your lamp has a heat up and cool down phase where the color temperature is low and will affect your filter settings. Although this is only a fraction of a second, it will become significant at shorter exposure times. Try keeping (partial) exposure times higher.

 

[inthedark]

Hi Thilo,

I'm J.Leslie, anyway. I have run probably close to 200 tests at different aperatures and exposures. In doing those I found that what you say is true, although I further found that the ambient temperature of the lite box itself has more effect than the exposure time itself. For expample if it take me a while to set up my shot and the lite box gets over 130. I set tests for
f5.6 4 secs, f8 8s, and f22 64s and they all look the essentially the same.
Then I let the deck cool to its pre-warmed 95-100 F degrees and do the same. This set also matches closely, BUT they look nothing like the first set.
Since I started trying to bring in color, my thoughts were similar to yours, but this test has me reconsidering the importance of the length of shot and more about how long it took me to set up. I also drilled 30 or more holes in my light deck to help it cool faster, since it seems easier to maintain the cooler temps than the warmer ones.

 

[Robert]

Doesn't somebody make a shutter for enlargers? Basically you leave it on more or less all the time. No need to worry about warm up/cool down.

 

[inthedark]

Yes, mine have shutters, but because my light deck is flourescent, the lights sit at a warm glow stage till the shutter/timer boots, then the machine kicks the lights to full. When the shutter/timer kicks off, the lights go back to glow.

 

[Thilo Schmid]

J.Leslie, if you are using a closed loop system, light switch phases are not your problem. Does your Enlarger have an IR filter? The cyan sensitive color layer of your paper is IR sensitive, too. IR light does have different straylight characteristics. It may e.g. be reflected by black walls.

 

[Donald Miller]

Yes, Ed, I think you re-stated my frustration quite well. My concern with a colored or filter dodger is that filters still let the image through somewhat and I'm afraid that the waving about in front of the image will let some of the image through distorted. I'll try it though and let you know.

I tried tri color printing last night to see if I could better control which colors are dodged/burned in. It was better but time consuming. I have 324 images to resolve this for, so the time cost will be frustrating with tri color. Again, something like the tri tone separation using hard line negatives that don millikan mentions in another thread might be adaptable to this problem, but to do so for so many images would be nuts.

Thanks so much for the quick response.

Interesting thread and the thoughts that have been expressed are pertinent. I have not worked with color in a number of years and the thoughts that I have on the subject may not be workable. However I will propose them anyway.

Sharp masking should be as applicable to color as it is to my darkroom practices in black and white. Sharp masks are very precise burning and dodging tools. As such they are density initiated. By using lithographic half tone film contact exposed to the original camera negative, the appropriate interpositive (for dodging purposes) and second generation sharp negative (burning purposes) could very easily be produced. This would insure greater repeatability when a large number of the same print are required. Additionally this would allow very precise burning with color filtration adjustments should that be appropriate (albeit, the adjustments would need to be determined by actual trial in your darkroom and with your materials).

As an additional thought and aside from the conventional printing and possible sharp masking I have mentioned, it would seem that using lithographic materials that one could do color separation masking by producing the appropriate color separations much as the matrices are in dye transfer printing. I would think that if one were to do this that the color fidelity would be greater then any other process currently in use.

The downside to both of the processes which I proposed is that very precise pin registration methods would need to be employed. However one additional benefit would be that if one were doing Ilfochrome the method to do unsharp contrast masking would already be in place.

As I initially stated, these are my thoughts on processes that are not currently being employed, at least to my knowledge. It might be interesting for someone to pick up the banner and work these out.

 

[Thilo Schmid]

Sharp masking should be as applicable to color as it is to my darkroom practices in black and white.

Don,
all kinds of masking techiques are applicable to color, too. But since color is an additional "dimension", you might need to dodge/burn to enhance color as well (or give it the expression you like). This can usually not be archived by means of masking. Another obstacle is that you cannot use ortho film for masking in this case. There is also a big difference in handling color negative vs. color reversal prints. Reversal paper has a very low paper grade and is thus more immune to all kinds of color shifts. CN paper on the other hand is very critical to filter settings and light quality.

 

[inthedark]

Don, yes the masking idea would work fine IF I was looking at only one or two at a time. BUT this is an aerial roll of 324 9"x 9" negs with what is colled a solar flare that moves slowly from the NE corner to the NW corner as the day of flying progressed. It is considered quite normal for this type of stuff. Most shops would leave that corner off colorwise and in densitywise. I am trying to get them both to settle.

Thilo, no I don't believe I have a closed loop system. It is just a really BIG horizontal camera/track/copyboard system. All open except the lightdeck itself. And actually I can pinregister lith film or ortho film which is the usual correction if density is the only issue. Surprising, when I used under developed lith film for a softer mask, it did change the color, but the wrong way, so the lith film's black must have a color registration on my camera. It was slight, but it is there. I have even used layers of frosted polycarbon, again does fine for density but it seems to hold back the yellow dye formation which would imply that it has a yellow cast. BTW the softer lith film held back the same color.

This evening when it cools down around here, I have to do this one way or another. As I was drifting off to sleep last night I thought of a potential solution. Maybe if in the strongly printing area I use one extra polycarbon layer and one .10 lavendar, instead of two of the pc, maybe. . . anyway I will let you know if it works.

 

[inthedark]

BINGO! It is all fixed. PLUS I have been able to run the gambit of enlargements from 400% to 3500% without any further issues!!!!!!

Anyway, for the "contact" prints the light lavendar (.05M + .05B) with the polycarbon "shade" works just fine.

 

[inthedark]

Well, it looks like I finally have success in printing even color and even tone for the whole roll. I know the last post I THOUGHT I did, but this only held true for individual images not intended to be spliced together. When I scanned the images to begin the 4' x 8' mosaic . . ., not even close. The scanned files really amplified even the slightest color shift. I have now arranged 7 color adjustment "sections" in addition to the previously mentioned lavendar correction. I mentioned the solar flare in one of the last posts, but I failed to mention that this flare shifts from the lower right corner to the upper left corner of the negative as each flight changes direction. This set up of seven filters is maintaining not only through one flight but so long as I flip the roll (easier than flipping the filters) for every other flight, the corrections are holding. YEAH!!

This past weekend I had an unexpected rush to mosaic 12 images mostly of foothills north of town for a client (ie no clean street lines to splice at, streets are more forgiving with color shifts) and it looks great! I've printed another 90 and started scanning them in yesterday for the big mosaic. (Of course then my puter crashed and I spent all day fixing it, but...)hopefully this time it will piece together without color incidents. When I get a little while later this week or next I will try to upload a corrected and an uncorrected image along with a rough sketch of the filter set up if anyone is interested.

 

[Ed Sukach]

My lawd!!! And I had been wallowing in self-pity when I had to struggle to make a color print where there was no gray card, and the film had been exposed with a strange light source.

This sounds like it would make a h**l of a screen play. "Appolo 13" pales.

 

[inthedark]

Yes, Ed, I am guessing so. Just a few days ago my local competitor who actually has the plane the special camera, etc. dropped by unexpectedly. Now this is pretty unusual as she refuses to fly for any competitors here in the state and she has the only plane and pilot that can do these jobs which explains why the roll of film I bought cost 12,500 instead of 6000. Anyway when she came in she kept looking at my walls like she was looking for something. I think she was looking for the new mosaic. My understanding is that last year they flew the valley in color but could not put together a mosaic that worked. This is heresay though. I get the feeling I will be beyond proud when it is finished. . .260 images spliced to look like one flawless images. Wish me luck.

 

[inthedark]

Well, I have been making reasonable progress on the mosaic. I thought I was going to have to start over one more time, but I think I'm just over reacting little. Anyway, who would've thunk that with two weeks of figuring out this multi-tonal-chromatic filter thingy (don't you just love my great technical jargon :grin I would have a customer come in who has a slide with solar flare graduating from one side to the other due to photographing water at what must have been a bad angle or wrong time of day or something. Anyway, I won't get to his job till Tuesday, but I was able to say with a little sense of confidence, "yep, I think I can handle that." Wierd huh, how things work out.