Supra Endura Reciprocity Failure

[perkeleellinen]

Does anyone know at what point reciprocity fails with Supra Endura paper. The only data sheet I could find suggested an exposure range of 50 nanoseconds to 10 minutes, is that correct? Maybe that is for the new digi paper.

I ask because last night I was making some test strips from a Ultra 50 neg which was even denser than this film normally is. I managed to get everything right with an exposure of 55 seconds (@f5.6). Crazy length of time, but it was quite fun last night watching how colours change as the time lengthened. Anyway, I want to cut this exposure time down and would like to know if reciprocity has failed.

 

[hpulley]

50ns to 10 minutes is correct: http://www.kodak.com/global/en/professional/support/techPubs/e4021/e4021.pdf

55 seconds is absolutely no problem with reciprocity and at f/5.6 that is a dense negative indeed! You should be able to shoot at half that time at f/4 or one quarter at f/2.8 but of course you'll want to make test images/strips to be sure.

Discontinued but I still have boxes of Endura and I think it is great paper. Still haven't tried any modern Ultra Endura or Edge to see how they compare.

 

[perkeleellinen]

Thanks, my plan is indeed to cut the time by half and open a stop.

Great paper indeed!

 

[2F/2F]

55 seconds is not all that long. I've made color prints at 3 minutes. They were 20x24's, of course, but the exposures were predictable at those times.

 

[perkeleellinen]

Well, it was a success. I cut the time by half and opened up a stop and everything seems fine. I think the 55 seconds was the longest exposure I've ever made (it was a 5x7 print).

 

[pentaxuser]

55 secs is indeed incredible. With the same paper and a 5x7 print under only a 75W bulb I needed 6.8 secs at f11 or under 2 secs at f5.6!!!

I wonder what accounts for this kind of difference?

pentaxuser

 

[brucemuir]

What is "Ultra 50"
Is that an older Kodak emulsion similar to UC100/400? (UltraColor)

 

[hpulley]

Dense negatives make the difference. I overexposed some Ektar and did 35s f/16 exposures which I thought was long for a 5x7 (needed to dodge some) but wow, 55s at f/5.6 is some really dense negatives! Seriously dense.

 

[perkeleellinen]

What is "Ultra 50"

Agfa Ultra 50.

I've read that the rumour back when this film was current was that it was really an ASA 100 film which Agfa encouraged photographers to over expose by labelling it ASA 50, supposedly this exaggerated contrast and saturation. This would certainly explain the density of the negatives. This film is always dense, but this frame in particular is extra dense because I shot with an ND filter which resulted in a shutter speed of over 1 second. As my FM2 doesn't go lower than 1 second I just counted the seconds on my watch and erred on the side of (even more) over exposure.

 

[perkeleellinen]

Isn't it strange (annoying) how digital 'normalises' everything? These two photos look worlds apart in my hands but have somehow become similar after being photographed. When I printed each of these I thought the colour balance was about right with each, but when I place them together I think the Reala (left) shot is far too cool and the Ultra 50 (right) is far too yellow. But when I look at them separately, they both seem fine. I've shown them to friends and they think the same. They were taken about 10 minutes apart.