Pyrocat HD film speed

[Amund]

How are you guys and gals rating your film with Pyrocat HD?

 

[Leon]

How are you guys and gals rating your film with Pyrocat HD?

When I used a kit form p-cat and didnt use isopropyl alcohol with the phenidone at 1;1:100 i was typicall losing around 1 stop of film speed or more (fp4 at 80, hp 5 at 160, delta 100 at 50)

now I mix it myself and make sure I get the phenidone into solution, I get full film speeds in most situations.

 

[Baxter Bradford]

Leon,
I have just placed an order for chemicals to mix some Pyrocat HD. But didn't know about the need for Iso-propyl alcohol. Could you give a bit more info please?

Also the chap from Retrophotographic didn't stock Potassium Carbonate and persuaded me that I could use Sodium Carbonate instead. Any advice on how this might affect development/film speed kindly appreciated. They have added Pyrocatchetol to their raw chemicals list and prices. It was in stock, just not on the website (www.retrophotographic.co.uk)

 

[Leon]

baxter - the phenidone is difficult to dissolve in water so in the formula in his article at unblinkingeye.com, Sandy King recommends (where 2.0 g of phenidone is called for to make 1000ml stock a solution)

Mix 2.0g of Phenidone with about 5ml of isoprophyl alcohol and stir into an even paste, then add to the stock solution and stir until dissolved.

I'm not particularly good with chemistry - but from the same article as above, Sandy King suggests

Sodium carbonate can be substituted for potassium carbonate in the Pyrocat-HD formula. The two carbonates give virtually identical results when used at equivalent chemical weight in the working solution. However, sodium carbonate is much less soluble than potassium carbonate so it must be mixed as a weaker stock solution. To prepare a Stock Solution B with sodium carbonate, add 200g of sodium carbonate to 1000ml of water. To make a working solution for silver printing that would be exactly equivalent to the regular 1:1:100 dilution when using potassium carbonate, mix One Part A + Five Parts B + 94 parts Water. For alternative printing the working solution should be mixed 2:10:92 to exactly match the 2:2:100 dilution with potassium carbonate. For all practical purposes you could just mix the working solutions with sodium carbonate at 1:5:100 or 2:10:100 and make minor adjustments to development times as required.

 

[Baxter Bradford]

Fantastic Leon

Thanks very much, you are a star (and significantly better chemist than I!)
I shall find the article and print it out.

 

[jim appleyard]

I have no trouble whatsoever in dissolving phenidone in ordinary tapwater; all it takes is a slight amount of stirring, however, I've heard this complaint before. What am I doing right/wrong?

 

[juan]

I have to use alcohol to get the phenidone to dissolve. I've used sodium carbonate rather than potassium carbonate for a couple of years without problem. Rather than mix a stock B solution, I've figured out how much carbonate is needed in the working solution and stir the carbonate into the water, then add the A solution.
juan

 

[craigclu]

I have no trouble whatsoever in dissolving phenidone in ordinary tapwater; all it takes is a slight amount of stirring, however, I've heard this complaint before. What am I doing right/wrong?

I use distilled water but I have had the same experience and wondered why I don't have the issue that others mention. I use a magnetic stir so perhaps if I was doing it by hand, I would feel it took too long to dissolve, also.

 

[jim appleyard]

I use distilled water but I have had the same experience and wondered why I don't have the issue that others mention. I use a magnetic stir so perhaps if I was doing it by hand, I would feel it took too long to dissolve, also.

I just looked at the bottle of phenidone. It's phenidone A from Artcraft Chemicals. Apparently there are different types of phenidones out there. Perhaps this could explain it.

 

[gainer]

I keep phenidone in a glycol, either ethylene or propylene, solution. I think it could go as high as 5%, but I use 1% because phenidone is used in such small quantities along with ascorbic acid or catechol, hydroquinone or pyrogallol that the 1% solution is easier to measure. It keeps very well in such solutions.

 

[Amund]

Eh-hem, I feel hijacked here ....
Get back to the topic please

 

[jgjbowen]

I rate Tmax 400 at 320 with Pyrocat-HD from Photographers Formulary premixed at 2:2:100 dilution. I have a Zone VI modified spot meter and the .1 over FBF = 320.

Develop for 14 minutes @ 68 degrees in trays with once through the stack every 30 seconds. Lovely prints on Azo grade 2.

 

[brian steinberger]

Wow! This thread did get highjacked. I rate my Tmax 400 @ 500 and develop at 1:1:100 for 11min. at 70 degees.

And also, my FP4 rated @ 100 for 8 min. same.

Hope this helps!

 

[sanking]

In my own real tests for film speed, which have been very rather tightly controlled with sensitometry, I have always gotten slightly higher real true film speed with Pyrocat-HD (and Pyrocat-MC) than with D76 1:1, and slightly more than with PMK. But about 1/4 to 1/3 less EFS than with Xtol 1:2.

I would add that if you are printing on VC silver papers you need to develop for a lot longer to get the same results on the print than when printing on graded silver papers. This is true with all staining developers. I believe some people mistakenly confuse the energy of the developer at a certain dilution to develop a negative to the needed contrast with effective film speed.

Film speed must be evaluated on shadow density when the negative is developed to the right contrast to print with your process, either with a given VC filter or a given contrast grade. If these conditions are met you should actually be gaining some film speed with Pyrocat-HD and Pyrocat-MC compared to D76 which is the defacto standard. If you are not, there could be something wrong with the phenidone.


Sandy King

 

[noseoil]

Box speed

Here's a shot at box speed done with Efke 100 from this weekend. I used minimal agitation and the 1:1:150 dilution for this roll of 35mm. Typically, I rate the film a bit slower to get better detail in the shadows, but I had to shoot at the air show with this roll, so 100 was what I did to get a bit more speed. The detail in the uniform which is in shadow was let go. Minimal agitation helped with speed in this case. The shot I posted today of the Blue Angels in the standard gallery was the reason for bumping up the speed. I tend to like Efke 100 with a bit more shadow density, but in a pinch, it does well enough at 100 for my tastes. As Sandy has said, it depends on your process and the paper you use for printing.

Take a close look at the edge effects around the uniform, a benefit from minimal agitation. My son and his friend were going to the air show, but this shot is a 5x7 which is cropped and enlarged from a frame having both young men in it. Pretty decent for a shot which has been enlarged to 5x7 from essentially a half-frame of 35mm. Thanks again Sandy for a great developer. tim

 

[Donald Miller]

I rate Efke PL 100 at EI 50 (pyrocat HD 1-1-100) for SBR 7 (normal brightness range), EI 80 for SBR 6 (appr + one) and EI 100 for SBR 5 (appr. + 2).