View Full Version : PMK - Film Density Discrepancy?

William D. Lester
14-Aug-2007, 11:36
On page 64 of Gordon Hutchings Book of Pyro, he describes target densities of 1.60 for a Zone 7 exposure using variable contrast paper. Steve Simmons has suggested a Zone 7 density of 1.35 which is a common target for non pyro negatives. That's a fairly large difference. My negatives look fairly dense. Others have suggested that pyro negatives should be relatively thin. I am using the blue channel on my Xrite 810 to determine my net densities. I'm using FP4 and PMK. My FB+F is .08. My Zone 1 density at EI125 is .20 less the .08 for a net density of .12 - well within Hutchings recommendation of .1 to .2 for Zone 1. My Zone 7 net density at 10min developing time is 1.58. Almost textbook stuff according to the Book of Pyro. It's just that the higher zones look so dense. I haven't really taken time to make prints using these EI and developing time. My thinking was that I would do the tests first. Can anyone offer any guidance as to what target I should be using?

steve simmons
14-Aug-2007, 12:42
Ultimately the target is what density gives you the tone you want for zone 7.

None of these figures can be used as a gossipal (SP?) Your stain will vary depending on your water supply, agitation, etc., 1.6 was Gordon's total density, net density is really around 1.45-1.5. My net density, and I apologize for not making this clear, is 1.35. If you tray develop, as I do, you will get more stain because the wet flm is exposed more to the air then it will be if you use hangers and tanks, roller processing, etc.

People who use a densitometer for stained negs can become too zealous in their search for the perfect density when the real goal is the desired tone on the print. I use vc paper w/o a filter which is about the same as a #2 filter.

Try the Picker method to get the correct density for what tone you want. Then if you want to check the density if you are curious you can do so. That density then becomes your target.

steve simmons

William D. Lester
15-Aug-2007, 05:04
Thanks Steve. That was precisely the kind of answer I was looking for.