reciprocity color shift in color film

I just got may 4 x 5 transparancies back from the lab after a week in Zion National Park. This was my first try back into color work in many years. I Took some quickload Fuji Provia 100 to try out. For the most part, I was very pleased with the results. However, I did experience rather unplanned results in color shifts for longer exposures.

I spent one day in the slot canyons in the Narrows of the Virgin River. If you haven't ever been there, it's hundreds of feet of sheer cliffs straight up from a 20' wide (or less) river bed. Nearly all the light available is reflected light off the canyon walls. The rock is a combination of yelows, reds, and blacks and the effects are very dramatic. However, it's pretty dark in some places and longer exposures are many times required.

I have never really done much work in dark areas like this with exposures over one or two seconds. So without anything better to go with, I used a rule of thumb to double the meter reading for time and it seemed to work pretty well for final exposures. My exposures were up to about 8 seconds. However, the longer the exposure, the more the colors shifted towards violet. The brillient red cliffs are now a muted purple brown and the dark greys are now purple blacks. Obviously, this can be corrected in photoshop if I choose to go digital for printing. I assume that it can somewhat be corrected in the darkroom for traditional printing, but that would be pretty much trial and error (I used to do Cibachrome way back when).

As I said, this is my first time back with color in a long time and I've never used Fuji film before. My question is what do all of you "experts" out there plan for in this type of situation? Is there one type of film that you would recommend over others to limit this from happening? Do you try to use some sort of filtration in the field when the exposure is done to correct for it. If so, I would think that I would still get unpredictable results. I am extremely pleased with what I got back from my trip. However, I need to do something to correct for these color problems if I want to print any of them, and I would like to at least be able to plan for things like this in the future. One of my next trips that I would like to make is to the slot canyon in Page, Arizona. I've seem so many beautiful pictures of that area and wonder why I haven't read of similar problems there.

One other thing that I've wondered - the day I was there was a cloudless day with brillient blue skys. Perhaps I was getting a lot of reflected blue light down the canyon walls from the sky above.

Do any of you have advice or experienced similar problems?

Thanks

I'd guess it probably had a lot to do with the light rather than a color shift from the exposure. I don't use Provia, but I do use Astia. One my main reasons for using it is that it stays pretty good reciprocity-wise up to 120 seconds. I'd be surprised if Provia had problems with 8 second exposures.

I shoot Velvia 50 (40) almost exclusively, and it has terrible reciprocity charictaristics. One of these days I'm going to spring for some magenta gels, until then I'll just keep my exposures under a second.

I'm not entirely sure what the problem could have been, but Nathaniel may have been right about the light. I have been using Provia for several years, using exposures of 30 seconds or more regularly with no problem. The literature on it states that no adjustment is needed up to 128 seconds with no adjustment. After that, a filter is used as stated here: http://www.fujifilm.com/JSP/fuji/epartners/bin/Provia100FAF3-036E.pdf

I love those purple colors. And I do believe that much of it is blue light form the sky mixing with red from the rock. I actually try to capture some of that coloration in slots - check out this photo of mine:

http://www.keyesphoto.com/HeartChamber.html

You cantry to filter it out, but next time you are in a slot, look around and check out the range of colors that are there, sometimes it's not just all warm colors.

There should not be that much shift in 8 seconds. I think it might be the Provia. IMHO Provia colors are usually just dull. Certainly not the "pop" of Velvia. I would think Velvia or Astia would be better choices, maybe even Reala.

Maybe try the Singh Ray Lux filter or an 81 series might help too.

Thanks to all for your feedback. The more I think about it and look at the images, the more I think that the reflected blue sky had a lot to do with it. Perhaps with a cloudy day, the effect would have been different. Kirk - thanks for the link to your website. Loved seeing your beautiful images again. Gets me motivated to go to Arizona. I stumbled on your website somehow a while back in searching for info on the slot canyons. The purple colors you mention and show in your images are somewhat like those I experienced in Zion.

"I shoot Velvia 50 (40) almost exclusively, and it has terrible reciprocity charictaristics. One of these days I'm going to spring for some magenta gels, until then I'll just keep my exposures under a second."

How about 30 minutes with some filtering 81EF or some of its ilk?

I agree with some of the comments above. It was probably a true color shift in the light rather than reciprocity. I do twilight shots of architecture all the time with exposures routinely braketed from 15 sec to 2 minutes with Velvia 100F and don't get significant color shifts between exposures. Modern films are much more stable. Especially the Fuji films.

Dan - thanks for your comments on my photos, I'm glad you liked them.

I've been in Antelope Canyon on a partly cloudy day, and it was a very different set of colors than on a cloudless day. The blues and purples that I was looking for were not there, it was all red, orange and yellows. That's why I'm pretty sure it's the light and not reciprocity that you are seeing.