I had always thought my darkroom was fairly well calibrated. I know my chemistries and I know what times should get me the density ranges I am looking for. I noticed a trend recently of what I thought was weak development. I thought maybe my chems were going bad and I started using a lot of VC paper at grade 4. So I got out the densitometer and started checking. My highlight densities are all where they should be at about 1.3. The base fog on the other hand was more like .4 and .5. So the top densities did not drift down but base fog is creeping up and the result is I am struggling for contrast.
I generally use a fair amount of film and I usually buy expired film (a few years expired) My normal roll film combo is TRI-X and Pyrocat-PC Glycol. I also do a lot of pushing of roll film also using TRI-X and PC-TEA at ASA1600. This combo has always been calibrated for a lot of base fog and I get a lot of contrast and density anyway. I generally use grade 1 filters to get a good print which. The base fog is high but there is lots of density to "print through"
These remarks are that my darkroom calibrated did not include a consideration for rising base fog from aging stocks of expired film. Now I know that film that I suspect will have high base fog will likely need 20% at least more time to increase the whole range to print through. Even at that, my highlight densities should be at 1.75 and base fog at .5 giving me my working range of 1.25. I do not believe that at this range, there will be a significant difference in the overall look of the print and I should be at my target DR for Grade 2. My original calibration was for a DR of 1.25 with a base fog of .15 and highlight densities of 1.4. I had not read anyone making observations or comments regarding this and was wondering if anyone else ran into this? Or am I the only cheapskate who uses mostly $2 a roll TRI-X.
I generally use a fair amount of film and I usually buy expired film (a few years expired) My normal roll film combo is TRI-X and Pyrocat-PC Glycol. I also do a lot of pushing of roll film also using TRI-X and PC-TEA at ASA1600. This combo has always been calibrated for a lot of base fog and I get a lot of contrast and density anyway. I generally use grade 1 filters to get a good print which. The base fog is high but there is lots of density to "print through"
These remarks are that my darkroom calibrated did not include a consideration for rising base fog from aging stocks of expired film. Now I know that film that I suspect will have high base fog will likely need 20% at least more time to increase the whole range to print through. Even at that, my highlight densities should be at 1.75 and base fog at .5 giving me my working range of 1.25. I do not believe that at this range, there will be a significant difference in the overall look of the print and I should be at my target DR for Grade 2. My original calibration was for a DR of 1.25 with a base fog of .15 and highlight densities of 1.4. I had not read anyone making observations or comments regarding this and was wondering if anyone else ran into this? Or am I the only cheapskate who uses mostly $2 a roll TRI-X.
