Pyrocat and flat scenes....

[Tom Stanworth]

Just tried expansion in pyrocat for the first time and it worked very well. Time kept same as 1:1 and just used 1.5:1.5. I placed the shadows on Z2.5, highlights falling on 6 (so I knew I would be unlikely to blow this one in my play about) and now a contrasty glowing print on G2.5 VC. I intend to be a bit more methodical in future but this worked nicely. I am tempted to use concentration increases for expansion rather than time as I want to keep times reasonably short at 20 degs C. Can anyone see a problem with this?

I think some of my concerns about flat subjects (and therefore) expansion were becasue of the terrible experiences I am having with some 10x8 Maco 100 (efke 100 supposedly)...

Seems to be great so far....so perhaps I am not far off being a one dev photographer!

Tom

 

[sanking]

I am tempted to use concentration increases for expansion rather than time as I want to keep times reasonably short at 20 degs C. Can anyone see a problem with this?

Tom

No, in fact I think it is a great idea. I am thinking about working out some different N+ and N- for my favorite films times based on change of concentration rather than changes in time because this will eliminate the increase in B+F that accompanies long development times, especially when developing for alternative processes.

Sandy

 

[Tom Stanworth]

Just an update on the 10x8 Maco up100 (efke?) I have been having problems with. I just souped the hell out of it using DDX 1:4 at 25 degs C and 15 minutes constant agitation. Still very poor max density despite (just) decent shadow detail (rated at ISO 80 as I intended to expand the scene using pyrocat originally.). I am really not getting anywhere, whereas the other films I have tried work faultlessly in terms of building contrast. Seems that there is something wrong with this film. For whatever reason it is Sh**e! Lets face it if in DDX it just scrapes ISO 80 when dev'd for this long it lacks speed AND Dmax. Reminds me of what people said about bergger being no good for expansion, but great for really contrasty scenes needing N minus development. I'm sprinting back to the warm ilford bosom, now that it available again and never going back. That base fog regardless of developer and susceptibility to scratching is a real pain. The first time I tried Efke pl100 was shooting contrasty water scenes and the prints were lovely. Jut aint working for me in Wales! Maybe dodgy old knackered film I s'pose....

 

[Kirk Keyes]

No, in fact I think it is a great idea. I am thinking about working out some different N+ and N- for my favorite films times based on change of concentration rather than changes in time because this will eliminate the increase in B+F that accompanies long development times, especially when developing for alternative processes.Sandy

Does this really happen, Sandy? I've never tried changing developer concs, just time. Why does the B+F not increase proportionally to the contrast index, regardless of the time it takes to generate a given contrast? Afterall, higher strength developer will be more active so it should build fog levels faster than a lower strength developer given the same amount of time. Maybe you have some data to demonstrate this?

THanks - Kirk

 

[sanking]

Does this really happen, Sandy? I've never tried changing developer concs, just time. Why does the B+F not increase proportionally to the contrast index, regardless of the time it takes to generate a given contrast? Afterall, higher strength developer will be more active so it should build fog levels faster than a lower strength developer given the same amount of time. Maybe you have some data to demonstrate this?

THanks - Kirk

Kirk,

What Jay suggests in his related message is very similar to my own intuitive reasoning on the matter. But no, I don't have any data to demonstate that it indeed happens this way, though I have quite a number of observations that suggests that the mechanism he describes is the operative one.

Sandy

 

[Jorge]

Does this really happen, Sandy? I've never tried changing developer concs, just time. Why does the B+F not increase proportionally to the contrast index, regardless of the time it takes to generate a given contrast? Afterall, higher strength developer will be more active so it should build fog levels faster than a lower strength developer given the same amount of time. Maybe you have some data to demonstrate this?

THanks - Kirk

Based on empirical expereince I say it works pretty good. This was my favorite way of working with Tmx RS and Tmx 100. I used 1:15 for n-2, 1:9 for normal and 1;4 for N+2 all developed at 9 min at 72 ºF. I must say the fog levels were very low for the 1:4 solution. Of course this was done for silver printing, and I have not tried it with pyrocat nor am I likely to try it, I tend to stick with what works for me. So low fog levels for higher concentrations of pyrocat might not be the case, but it is worth a shot and experiemnting.

 

[Kirk Keyes]

jdef wrote, "It seems to me that a dilute solution's activity would be progressively reduced by oxidation, extending development times, and increasing general stain."

So Sandy (0r others, I guess), is this more an issue/effect with staining developers then, or as Jorge indicates all developers?

Kirk

 

[Kirk Keyes]

I would think that if the oxidation product of a developer causes fog, then the same principles would apply. It would seem especially important in a staining developer, but perhaps not limited strictly to them.

Jay

But will not unoxidized developer generate fog as well? Hence my suggestion that more concentrated developers will increase fog too?

 

[sanking]

But will not unoxidized developer generate fog as well? Hence my suggestion that more concentrated developers will increase fog too?

Time is also a factor in the development of B+F stain. If you can develop the film to the desired CI in 12 minutes in a strong solution you will have less general stain than if you develop the film to the same CI in a very weak solution for 45 minutes, assuming symmetrical parts of Solution A and Solution B. For example, I have observed that for the same CI I get more B+F stain with long development and weak solutions (as with stand and semi-stand development) than with rotary development and strong solutions. That is why I have recently started to recommend an asymmetrical ratio of about 3:2 A:B when long development times are required as this reduces B+F stain. One of the things that surprised me intially with semi-stand development is that the developer is virtually clear after development, with no hint of oxidation, but nevertheless, B+F stain is fairly high. Why is that? I am not entirely sure but part of the answer appear to be simply that the film was in contact for a much longer period of time with developer by-products.

However, regarding many of the specific questions raised here I really am not sure of the answer and am simply speculating. I will try to test the concept sometime in the near future and will let you all know what I find.

Sandy

 

[Ole]

This concentration/time/oxidation/fog thingy fits in well with my experiences with other (improvised) staining systems.

I needed to intensify a negative, and did a bleach and redevelop. The redeveloper was one teaspoon pyo, two teaspoons potassium carbonate, one liter water. Stain was massive, so was base fog. Developent ended when the developer died - it was nearly black by that time.

Another version was a negative I realised was underexposed (for Pyrocat-HD) and needed lots of shadow detail (don't ask...). First development for four minutes in Neofin Blau, then eight minutes in Pyrocat-HD 2:1:100. Good shadow detail, very high base fog, and a fully usable negative!