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View Full Version : reciprocity characteristics of slide vs. b/w



scott russell
14-Jun-2008, 13:43
So,

I've read data sheets on the fuji site that claim most of their slide films don't need reciprocity adjustment unless the exposures are over 2 minutes. On the other hand, this data sheet for fp4 here (http://www.ilfordphoto.com/Webfiles/2006216115141521.pdf) Says that an exposure as short as 8 seconds would require 25 seconds of extra time to compensate; and for a 30 second exposure, you should add 150 seconds. Does this sound about right? That's a pretty drastic difference that i wasn't aware of.

Bruce Watson
14-Jun-2008, 14:39
So,

I've read data sheets on the fuji site that claim most of their slide films don't need reciprocity adjustment unless the exposures are over 2 minutes. On the other hand, this data sheet for fp4 here (http://www.ilfordphoto.com/Webfiles/2006216115141521.pdf) Says that an exposure as short as 8 seconds would require 25 seconds of extra time to compensate; and for a 30 second exposure, you should add 150 seconds. Does this sound about right? That's a pretty drastic difference that i wasn't aware of.

FP4+ is an older film. More modern films tend to have better reciprocity characteristics. Some of Fuji's films are amazing in this regard, as are the newer Kodak films like the Portra series and the two Tmax films.

IOW, both are correct. The data sheets in general don't lie. At least not too much.

Ron Marshall
14-Jun-2008, 20:08
What Bruce said. I love FP4, but switched to Acros after a ten minute exposure. Acros, TMX and TMY all exhibit favourable reciprocity.

Ken Lee
15-Jun-2008, 04:10
Color films combine sensitivity to Red, Green, and Blue in one layer, but each dye has its own characteristics. One of the arts of making color film is getting those curves to line up, under a wide range of exposure and lighting conditions. At the extremes, you will find that colors do shift, relative to one another. With black and white however, there is only one curve to worry about, and as the others have pointed out, more modern films are very good in this regard.

scott russell
15-Jun-2008, 08:32
that's sad about the older films, i always preferred the look of fp4/hp5 and tri-x and i don't think i could get myself to use tmax. Ilford delta film seems to have the same slow characteristics too. If only Across came in boxes instead of readyloads...

Bruce Watson
15-Jun-2008, 08:52
that's sad about the older films, i always preferred the look of fp4/hp5 and tri-x and i don't think i could get myself to use tmax. Ilford delta film seems to have the same slow characteristics too. hmm maybe i'll look into Acros...

Sad? That's not what I was thinking at all.

What I see is that people wanted sharper, less grainy, more linear films with better reciprocity characteristics. The manufacturers listened to the marketplace and provided what they said they wanted. Isn't that the way it's supposed to work? I think it's called progress, and it is, in general, a good thing.

I didn't think I'd like 5x4 TMY-2 either. I was wrong -- it's looking to be a great film for me. Good enough that I don't anticipate buying any more Tri-X in the foreseeable future anyway.

Still, if FP4+ is what you want, there's no reason not to use it. You should use the film with which you are most comfortable. Just carry a reciprocity table with you for those long exposures and you should be fine.

scott russell
15-Jun-2008, 09:03
its not sad they are making better film, i just remember using tmax in school and immediately going back to ilford just because it looked better to me. i then tried tri-x which still looked smoother than the tmax. the newer films are also looking to be more expensive..

Eric Leppanen
15-Jun-2008, 09:15
If only Acros came in boxes instead of readyloads...It does, if you don't mind paying a premium for it and importing it yourself (it's still much cheaper than Quickloads):

http://www.unicircuits.com/shop/product_info.php?cPath=27&products_id=40
http://www.unicircuits.com/shop/product_info.php?cPath=27&products_id=124

Badger Graphic also normally stocks 4x5 Acros sheets, but they are currently out of stock according to their web site.

Ken Lee
15-Jun-2008, 13:22
I'm not sure what special quality people admire in the old emulsions. Perhaps someone would like to post a photo which demonstrates it.

From an aesthetic perspective, I find nothing lacking in TMY. Here's (http://www.kenleegallery.com/html/portraits/index.html?5) a recent shot made on 4x5 TMY, developed in Pyrocat HD. No burning or dodging was done at all. I can't imagine getting better tonality, without shooting a different subject. Maybe the secret, is that old Tessar I used. My modern lenses see little action these days.

So try some modern emulsions, with some old lenses. You're in for a treat. ;)

CG
16-Jun-2008, 10:57
I'm not sure what special quality people admire in the old emulsions ...

I'm guessing it's basically the curve: the long toe and more pronounced shoulder etc - i.e. comressed shadows and opened up mid tones etc , rather than any quasi-magical qualities sometimes attributed to older films.

C