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.
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.
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.
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.
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.
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.