Pyrocat and densitomiters.......

[Mike Lyons]

O.K, could someone clarify the advice given by Sandy King at the Unblinking Eye articles site? I am using an X-Rite densitometer set on the yellow/blue channel, as advised for Pyrocat-hd due to the staining colour. I normally use a Zone system method, with Zone 1 at about 0.10 above f+fb, and Zone 8 at about 1.30 above f+fb densities. The question is this, with Pyrocat-hd, can I use the standard Zone densities mentioned previously, or do I accept the "thinner" look of negs as part of the staining process and develop to a lower CI than normal? Call me "technically challenged" if you like, but I find ( at my current level of expertise) some of the info a bit confusing. But you lives and you learns. FWIW I am printing on silver/gelatin FB and RC VC papers with a Diffuser type (LPL) enlarger.
Thanks for a great site.
Regards- Mike

 

[KenM]

You will find that pyrocat negatives do look slightly thinner, but it's misleading due to the staining of the developer. Use your densitometer to get in the ballpark (which it appears you've already done), but let the print tell you if you're on the right track. How are the highlights? Too white, too gray? Adjust development accordingly.

Please don't get fixated on the 0.1 over fb+f standard - I used to do this, and more often than not my shadows were quite weak. I would suggest placing the shadows on a higher zone to get them well off the toe of the film - you'll get better separation in the shadows, and you won't block up the highlights since todays films have such a long straight line section. For standard emulsions (such as Tri-X and HP5+) you probably won't start hitting the shoulder until zone XV. Yes, you're printing times will be longer, but so what?

When you meter the shadows, you're reading an area, and sure enough some of the shadow areas will fall on zone II,even though you meter it as zone III, assuming of course that the shadow area isn't one single tonality, very evenly lit - by moving the shadow exposure up the curve, you'll get the darkest shadows on III, giving you more separation, and therefore richer detail in the shadows.

Good luck! Pyrocat is a great developer - I've used it in the past, and I'll use it in the future.

 

[Mike Lyons]

I'll be hitting the darkroom this weekend, so I should be able to get a feel for how the densities print. My first tests with Delta 100RF gave a surprising effective speed of around 160-200asa (unless I've stuffed something up!) but the next roll on Delta 400 was spot on for that asa.The 100 film high values seemed O.K for normal densities (i.e. not thin at all) but the 400 film was much lower in the high values- hence the question; do I go by previous experience or try a change to developing times based on others advice. I suppose the proof will be in the printing.Much higher general stain on the 400 film, but this could be a character of the film, I suppose. Early days yet.
Mike