Preliminary test results
Preliminary testing results on substituting other B&W developers in Ilfochrome:
First, I asked another photographer who at one time was a tech rep for Ilford USA and his job was to travel around and teach pro photogs how to use Ciba/Ilfochrome. When digesting his reply, note the source: " Yes, dev and fix are variants of B&W chemistry and I've found other developers to be inferior, and further, if you do not use Ilfochrome fixer, you will not get archival results." OK, so much for the company line.
Testing conditions as follows:
Printing from a known image, one 8x10 each developer variant, same enlarger height, f-stop, time and filter pack. All from the same box of paper. All processing done on JOBO CPP-2 once and dump. Bleach and fix drawn from same working solutions mixed for the session. Alternate developers run at same time/temp as Ilfochrome dev. Where there is ref to sodium thiosulfate, it is crystal obtained from Digitaltruth, what looked to be approx 1/4 teaspoon weighed out at 0.8 gram on lab scale accurate to +/- 0.1 gram. Where used, it is at 0.8g/litre of working solution dev. Control print made with fresh Ilfochrome developer in same session.
1) Dektol 1:3 - print ok density/contrast with some yellow shift, looks to be correctable with filter change
2) Dektol 1:3 w/sodium thiosulfate - same as (1) but a bit lighter, like somewhat overexposed
3) Ilford Warmtone 1:9 - almost a match for (1)
4) Ilford Warmtone 1:9 w/sodium thiosulfate - pretty good match for (2)
Note that this is not a comprehensive test as only one image was printed and cannot identify whether differences in highlight/shadow detail can be acheived with different types of images.
Anyway, this is a start - as always YMMV.
Bob