Recently there have been some discussions about various developers and how they act on films, and I thought I'd share an experiment I did back in January. I wanted to compare a "high acutance, compensating" developer with a very simple "average acutance, soft acting" developer to see for myself just how different the two could be.
I exposed four 5x7 sheets of Ilford Delta 100: two exposed at 64 ASA and two exposed with another half stop exposure, just so I had a choice between two exposure variations, for optimal results. One sheet of each exposure was developed in D-23 diluted 1:3 and one sheet of each exposure was developed in PMK (Pyro) at 1:2:100. The lens I used was the f7.7 Kodak Ektar 203mm.
I chose the 1:3 dilution of D-23 because literature I looked at suggested it becomes more of an acutance developer at high dilution, due to the reduced amount of sulfite in the highly diluted solution. Of course, development times become a bit long, but I found 15.5 minutes @ 70F to be acceptable. I used PMK at the standard dilution and time for Delta 100, which was 13 minutes at 1:2:100, @ 70F.
The D-23 negatives and the PMK negatives came out looking remarkably similar, aside from the PMK stain. When scanned, there was only a very small difference in the tonal scale of the PMK negs VS the D-23 negs, and in processing the images in Lightroom, I had to make only minor adjustments of the high values to result in a similar tonal range for each negative. The overall density of the negatives and the available shadow information was very similar for both negatives - they varied only in the highlight density, and that was a minute difference.
I'm guessing you'd like to know how the two developers compared as far as acutance and grain is concerned. PMK is known as an acutance developer with some compensating ability, preserving the fine details and definition of the high values while also masking grain somewhat, thanks to the Pyro stain. D-23 on the other hand - and this is why I chose it to make the comparison - is known as a "soft-acting" developer with low-to-average acutance and average (but sometimes mushy) grain. However, the negative developed in D-23 diluted 1:3 was remarkably similar to the PMK negative: very good acutance, excellent preservation of the subtle high values and crisp grain characteristics. I had difficulty seeing any significant differences in the resulting images from the two developers. There was, however, slightly better preservation of the very highest white values in the PMK negative, as expected. But the highlight information in the D-23 negative could easily have been preserved in print.
Here are some A/B comparisons of the PMK neg and the D-23 neg, at full size, and a crop at 100% to show fine detail. (The scans are uncompressed TIF files, at approximately 6000 x 8000 pixels).
The PMK images are on the left and the D-23 images are on the right.
Because these are screen captures, they don't show the resolution the full images have, so if you want to see the images at full size, the PMK image can be viewed here, and the D-23 image here. (To view at full size on Flickr, click twice to zoom)
I exposed four 5x7 sheets of Ilford Delta 100: two exposed at 64 ASA and two exposed with another half stop exposure, just so I had a choice between two exposure variations, for optimal results. One sheet of each exposure was developed in D-23 diluted 1:3 and one sheet of each exposure was developed in PMK (Pyro) at 1:2:100. The lens I used was the f7.7 Kodak Ektar 203mm.
I chose the 1:3 dilution of D-23 because literature I looked at suggested it becomes more of an acutance developer at high dilution, due to the reduced amount of sulfite in the highly diluted solution. Of course, development times become a bit long, but I found 15.5 minutes @ 70F to be acceptable. I used PMK at the standard dilution and time for Delta 100, which was 13 minutes at 1:2:100, @ 70F.
The D-23 negatives and the PMK negatives came out looking remarkably similar, aside from the PMK stain. When scanned, there was only a very small difference in the tonal scale of the PMK negs VS the D-23 negs, and in processing the images in Lightroom, I had to make only minor adjustments of the high values to result in a similar tonal range for each negative. The overall density of the negatives and the available shadow information was very similar for both negatives - they varied only in the highlight density, and that was a minute difference.
I'm guessing you'd like to know how the two developers compared as far as acutance and grain is concerned. PMK is known as an acutance developer with some compensating ability, preserving the fine details and definition of the high values while also masking grain somewhat, thanks to the Pyro stain. D-23 on the other hand - and this is why I chose it to make the comparison - is known as a "soft-acting" developer with low-to-average acutance and average (but sometimes mushy) grain. However, the negative developed in D-23 diluted 1:3 was remarkably similar to the PMK negative: very good acutance, excellent preservation of the subtle high values and crisp grain characteristics. I had difficulty seeing any significant differences in the resulting images from the two developers. There was, however, slightly better preservation of the very highest white values in the PMK negative, as expected. But the highlight information in the D-23 negative could easily have been preserved in print.
Here are some A/B comparisons of the PMK neg and the D-23 neg, at full size, and a crop at 100% to show fine detail. (The scans are uncompressed TIF files, at approximately 6000 x 8000 pixels).
The PMK images are on the left and the D-23 images are on the right.
Because these are screen captures, they don't show the resolution the full images have, so if you want to see the images at full size, the PMK image can be viewed here, and the D-23 image here. (To view at full size on Flickr, click twice to zoom)