Techpan in Pyrocat

[fhovie]

Somewhere around here I got the crazy idea I could use Pyrocat to develop Techpan using the semistand method. I shot a roll, half at asa 50 and half at 100. I used the Pyro 1:1:150 at 70F for 20 minutes with 4 agitations. I think it is probably N+2 or there abouts but the curve is very odd. - I am evaluating the negs off a scanner - so who knows how different it will be when I check them in the darkroom with graded and vc paper. It looks like zone 1 and 2 often did't show up at all. Low contrast shots landed right where they should (density wise) and look great. Zone 8 and up are very dense yet they did scan and look printable - barely.

I like the idea of using my main brew for all my films. Rateing Techpan at 100 is quite a stretch but worked for the most part. Is there a better way to get my toe and shoulder back? I think if I go longer it will give me a higher film speed but be even contrastier? If I go shorter I should get my highlights under control but need to rate it at ASA 25? Is there anyone who has a preferred method for this?? Even less agitation?

Thanks

 

[Donald Miller]

Somewhere around here I got the crazy idea I could use Pyrocat to develop Techpan using the semistand method. I shot a roll, half at asa 50 and half at 100. I used the Pyro 1:1:150 at 70F for 20 minutes with 4 agitations. I think it is probably N+2 or there abouts but the curve is very odd. - I am evaluating the negs off a scanner - so who knows how different it will be when I check them in the darkroom with graded and vc paper. It looks like zone 1 and 2 often did't show up at all. Low contrast shots landed right where they should (density wise) and look great. Zone 8 and up are very dense yet they did scan and look printable - barely.

I like the idea of using my main brew for all my films. Rateing Techpan at 100 is quite a stretch but worked for the most part. Is there a better way to get my toe and shoulder back? I think if I go longer it will give me a higher film speed but be even contrastier? If I go shorter I should get my highlights under control but need to rate it at ASA 25? Is there anyone who has a preferred method for this?? Even less agitation

Thanks

Frank,

I have no experience with this particular film/developer combination. What I might be inclined to try is to preflash the film at the 100 ISO rating that you used. My preflash exposure would be non-image bearing light placed at Zone IV and then I would base my image bearing light exposure on my highlight values. Placing them at Zone VIII.

My reasoning is that this will provide you support of your shadow exposure without materially affecting the highlight placement. The compensating effect of minimal agitation in Pyrocat would then keep the development times in a manageable perspective.

If you will check the two images that I have posted in the technical gallery, you can see the benefit of using this technique.

 

[Donald Miller]

Ansel Adams described the technique that Donald suggests in "The Negative", which is the same principle as pre-flashing paper. He also suggested tha the color of the pre-exposure could be used for contrast control, and suggested a yellow card, out of focus for the pre-exposure.

The technique that I have developed departs from that AA described. Although Adam's description will work to a certain degree.

 

[fhovie]

I know that with TD3 I always got good results - I just printed the negs mentioned above and they are at least N+2 perhaps a little more - I will try a littl more with Pyrocat - I would really like to be able to develop Techpan in it. I wonder what the formula is for TD3

 

[Black Dog]

TD 103

I know that with TD3 I always got good results - I just printed the negs mentioned above and they are at least N+2 perhaps a little more - I will try a littl more with Pyrocat - I would really like to be able to develop Techpan in it. I wonder what the formula is for TD3

Check out the TD 103 formula in The Film Dev Cookbook (Anchell + Troop).I suspect this is pretty much identical.