FP4+ tests, density

[Wayne]

I did some film and developing speed tests based on the Steve Simmons article in the most recent View Camera. Using FP4+ and HC-110 Dilution B in trays, agitating every 30 seconds, I've come up with an EI of 80 and a developing time of <5.5 minutes. The latter is a bit short, so I took some readings using my crude "densitometer", which consists of an EM-10 exposure monitor and a step wedge. I come up with an approximate density range of 2.8 from fb+f to the Zone 8 exposure developed for 5.5 minutes. Is this range (crude and probaby innacurate as it is) about right? I'm hoping maybe that density is higher than should be expected and I goofed somewhere, rather than having to start all over from scratch with Dilution H to get longer developing times. My initial film speed test was done at Dilution B for 9 minutes (from the massive dev. chart)

 

[sanking]

A density range of 2.8 would only work with processes of very high exposure scales, say salted paper or albumun, and the range would be great even for those processes. For silver printing the range needs to be 1.2 or less.

You have made a mistake in measurment because FP4+ will not develop to a DR of 2.8 in 5.5 minutes of development.

Sandy

I did some film and developing speed tests based on the Steve Simmons article in the most recent View Camera. Using FP4+ and HC-110 Dilution B in trays, agitating every 30 seconds, I've come up with an EI of 80 and a developing time of <5.5 minutes. The latter is a bit short, so I took some readings using my crude "densitometer", which consists of an EM-10 exposure monitor and a step wedge. I come up with an approximate density range of 2.8 from fb+f to the Zone 8 exposure developed for 5.5 minutes. Is this range (crude and probaby innacurate as it is) about right? I'm hoping maybe that density is higher than should be expected and I goofed somewhere, rather than having to start all over from scratch with Dilution H to get longer developing times. My initial film speed test was done at Dilution B for 9 minutes (from the massive dev. chart)

 

[Wayne]

A density range of 2.8 would only work with processes of very high exposure scales, say salted paper or albumun, and the range would be great even for those processes. For silver printing the range needs to be 1.2 or less.

You have made a mistake in measurment because FP4+ will not develop to a DR of 2.8 in 5.5 minutes of development.

Sandy

You are right of course, I screwed up. Thanks for confirming that! I went back and discovered that I took the reading off the wrong sheet late last night. I'm not sure I'm in better shape now though, because reading the correct sheet still gives me a DR of ~1.8 in 5.5 minutes-if I can trust the EM-10 readings to be somewhere in the ball park. Could I have developed that DR in that time?

When I exposed my sheets yesterday it was too dark to do them inside at EI 80 without messing with reciprocity, so I pointed my camera down from the balcony into the yard onto a wide uniform swath of snow. It was bright but heavy overcast with very even light, but is it possible I somehow grossly overexposed or something? I double-checked my meter readings and I did expose the way I intended.

 

[Wayne]

I did a little sensitometry with my spotmeter and also came up without 1.8, so that must be at least close to correct. Oh well, not sure what going on but I will repeat the developing time test again tonight starting with 5 minutes. I hope I did something else wrong like mixed the developer too concentrated or something, because I sure dont want 5 minute times.

 

[vet173]

For semistand I would have used a much higher dilution. D or E. If your negs print on a two they are no way near the DR you mentioned. You would be down to a 0 or 00 to get a print with that DR. Better yet just switch over to pyrocat now and be done with it.

 

[Wayne]

For semistand I would have used a much higher dilution. D or E. If your negs print on a two they are no way near the DR you mentioned. You would be down to a 0 or 00 to get a print with that DR. Better yet just switch over to pyrocat now and be done with it.

I dont consider agitation 2x minute semi-stand. I'm not printing these, except as part of the testing, they are tests only. I'm pretty sure the 1.8 is correct, or close. Pyrocat is on my to-do-someday-list, but not yet. Anyway I'm going to go to dil D next

 

[john_s]

I have done some tests using 2 different spot meters and I found that great care is needed to get anything remotely like accurate results. My best results were obtained using a flourescent tube light table, using a black mask covering all but the relevant part of the negative, and the room in darkness. Eventually a densitometer confirmed that the results were good enough to be of some use in determining development times and EIs.

 

[Wayne]

yeah, I was pretty careful about masking off the light table when I did the spot readings. The fact that my results were identical to the step wedge-EM10 estimates leads me to believe its not too far off the truth.

Anyway last night I tried it with Dilution D at 6 minutes, and its a step in the right direction but maybe not far enough. But I somehow got a film speed of 125 or greater, which leads me to believe I'm still building too much density too fast. I didnt test for faster than 125, but I suspect that it was at least 1/3 stop faster than that. I also suspect that when I test for developing time it will be less than 5 minutes, so I'm not going to bother. I guess I will try Dilution E next. Now I remember why I usually avoid these kinds of tests. :rolleyes: