There have been a few posts recently asking about Pyrocat and why it is superior to other developers. Here is a side-by-side study showing the difference between a general stain and image stain. Granted, the contrast inherent in the two images is not the same, but the "haziness" of PMK is evident in the lighter image. Both are contact prints of the same scene. They were taken in similart lighting conditions on the same day. I used PMK for a couple of years until I switched to Pyrocat.
The more contrasty image was done with Pyrocat-HD, Efke 100, minimal agitation, a 240mm G-Claron and was printed on the old azo grade 2. It's a crop from an 8x10 print, from which I tried to get a similar portion of the scene. While it shows better contrast, there is an overall sharpness and clean tonality which just isn't possible with the general stain present in PMK.
A friend graciously offered the HP5 image with PMK to do the comparison (thanks Ria). It was taken with a 300mm Symmar-S lens and 4x5 reducing back, HP5, and contact printed on Ilford FB paper. Development was with PMK with "normal" agitation, which means agitation cycles every 15 seconds to avoid uneven staining. This lens is incredibly sharp when looking at the 4x5 image in the "sweet spot" which was the center of the image circle. A lens hood was used and the reducing back was built with a recess to avoid internal flare.
While this test is in no way scientific, it does show a big difference between PMK & Pyrocat. Both exhibit good tonality, but the Pyrocat has a cleaner, sharper more vibrant look to it which PMK can't touch. Mnimal agitation helps bring out this sharp look. With "normal" development and Pyrocat, this would not have the clean sharp edge possible only with minimal agitation. The HP5 should have a sharper look to it due to grain size and a wonderfully sharp lens, but the general stain has the effect of masking the image so it looks less sharp and even a bit cloudy. tim
The more contrasty image was done with Pyrocat-HD, Efke 100, minimal agitation, a 240mm G-Claron and was printed on the old azo grade 2. It's a crop from an 8x10 print, from which I tried to get a similar portion of the scene. While it shows better contrast, there is an overall sharpness and clean tonality which just isn't possible with the general stain present in PMK.
A friend graciously offered the HP5 image with PMK to do the comparison (thanks Ria). It was taken with a 300mm Symmar-S lens and 4x5 reducing back, HP5, and contact printed on Ilford FB paper. Development was with PMK with "normal" agitation, which means agitation cycles every 15 seconds to avoid uneven staining. This lens is incredibly sharp when looking at the 4x5 image in the "sweet spot" which was the center of the image circle. A lens hood was used and the reducing back was built with a recess to avoid internal flare.
While this test is in no way scientific, it does show a big difference between PMK & Pyrocat. Both exhibit good tonality, but the Pyrocat has a cleaner, sharper more vibrant look to it which PMK can't touch. Mnimal agitation helps bring out this sharp look. With "normal" development and Pyrocat, this would not have the clean sharp edge possible only with minimal agitation. The HP5 should have a sharper look to it due to grain size and a wonderfully sharp lens, but the general stain has the effect of masking the image so it looks less sharp and even a bit cloudy. tim
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