Pyrocat HD and N+1/N-1 development.

Does anyone have experience using Pyrocat HD for N+1 or N-1 development? Specifically I am using Ilford Ortho Plus at 14:30 according to massive Dev with good results. But want to know if I should change from a 1:1:100 dilution for either direction of development and if the 30% reduction in time is a good rule of thumb.

There is unlikely to be a simple linear relationship between N-development and development time, so making generalizations about specific increment is difficult. The range N-1 to N+1 is more realistically achieved; further extensions in either direction require additional testing to figure out a more precise increment.

Having said that, I think that a 30% increase/reduction from your N-development time should be a good place to start, without changing the dilution. To illustrate the point, here's a plot of Delta 100 developed in Pyrocat HD 1+1+200, using semi-stand development. You can use it as a very general guidepost, but the actual time will be yours to figure out . By the way, this particular plot uses the calculations recommended in the book Way Beyond Monochrome (fig. 10, p. 138). Other sources calculate N-numbers slightly differently, so keep that in mind. My semi-stand routine is as follows: start with a two-minute continuous agitation, then let the film stand for half the development time, then make 2-3 inversions, and let it stand for the remainder of the time. Other agitation schemes would probably produce a somehwat different curve.

I have loads of experience with this developer and N+/- development... just not with Ilford Ortho-Plus. I've used mainly HP5, at 1+1+50 dilution for N+, and sometimes N. For N- I use 1+1+100.

Andrew O'Neill said:

I have loads of experience with this developer and N+/- development... just not with Ilford Ortho-Plus. I've used mainly HP5, at 1+1+50 dilution for N+, and sometimes N. For N- I use 1+1+100.

Click to expand...

For N @ 1:1:50, I'd love to know your times and agitations for (say) Tri-X and HP5.

bags27 said:

For N @ 1:1:50, I'd love to know your times and agitations for (say) Tri-X and HP5.

Click to expand...

I haven't used Tri-X since the mid 90's since I discovered HP5 (perhaps I should reacquaint myself with the 5 rolls of Tri-X 120 I have sitting in my film fridge...) My times are for rotary, continuous agitation, although at times I do semi-stand (I have a video on my channel about that...). My 1+1+50 N time is 9:00 at 21C. I wouldn't be surprised if Tri-X was around there, too. I have a video about Pyrocat-HD at various dilutions, and another about 2-bath that I'll be uploading (probably one of them tomorrow), all with HP5 (it's my main conventional b/w film)...

Andrew O'Neill said:

I haven't used Tri-X since the mid 90's since I discovered HP5 (perhaps I should reacquaint myself with the 5 rolls of Tri-X 120 I have sitting in my film fridge...) My times are for rotary, continuous agitation, although at times I do semi-stand (I have a video on my channel about that...). My 1+1+50 N time is 9:00 at 21C. I wouldn't be surprised if Tri-X was around there, too. I have a video about Pyrocat-HD at various dilutions, and another about 2-bath that I'll be uploading (probably one of them tomorrow), all with HP5 (it's my main conventional b/w film)...

Click to expand...

Thanks! I see you use Thornton 2-bath as well. That's an old reliable for me. Always interested in learning more about it!

bags27 said:

Thanks! I see you use Thornton 2-bath as well. That's an old reliable for me. Always interested in learning more about it!

Click to expand...

I am quite impressed with its' versatility.