Perhaps I'm an idiot? More 510 Pyro Questions. Density funtime challenge.

[trooper]

You might find it easier to first place your water in the beaker, then use a baby medicine/vitamin syringe to measure and dispense the concentrate. It almost mixes itself that way. My pharmacist gave me a handful for nothing and each one lasts many uses.

[jay_de_fehr]

Hi again, Mark.

 

I hope your midterms are going well. I have a few suggestions, and comments. I see no reason to draw out the concentrate with a syringe, and then transfer it to a graduate before adding it ot the mixing container; instead, just go from the syringe to the mixing container.

 

One potential problem with your testing method is the phenomenon known as the Intermittency Effect, in which several short exposures do not equal one long exposure. If you're committed to testing, you might consider purchasing a stepwedge from Stoufers for your test exposures. This method requires less film, less chemicals, and less time, while delivering more accurate results.I think once you get your testing procedure ironed out, you'll find your times very close to those reported by other users. Good luck.

 

Jay

[sper]

Wow. Intermittency Effect would explain quite a lot actually. The last two tests I've run

(10 zones per sheet) have been maxing out around a density of 1.40...and this is at a total

time of 24 minutes! My 5 zone sheets aquired much higher densities, this could indeed

explain my longer development times.

 

However, if you remember from earlier in our discussion, my test images at 7 minutes

were still quite thin and printed, as I thought they would, flat and muddy.

 

Aside from the density jump between sheets (zones V and VI), which is probably due

human error, my tests using two sheets with exposure over 5 zones was consitent with the

test images I was making. The density jump on my curve was throwing off my

determination of development time, but otherwise the data seemed to be good. I

processed four images at the 14:30seconds dev time and the negatives were nearly where

they should be. They were contrasty, but not so much that I could tell from the light table.

I still suspect my development time will be around 12 minutes.

 

I already know that my testing using two sheets was done incorrectly, but what puzzles

me was that my mistake seemed to register in the opposite way that it should have. I

stopped down to zone 1 from my meter indicated, made five exposures like a test strip. I

then flipped the carrier and stopped back to my meter indicated, or zone V. This is wrong

because I already exposed for zone V on the first side. So I should have opened up to one

stop above my meter indicated, right? This error should have simply given me a straight

line between V and what I thought should be VI, but I got a jump that looks as if I opened

up one zone to many, not one to little. Is my thinking right on this?

 

These tests are way easier with a hasselblad.

 

Jay, can you tell me the capacity for 510 Pyro with 4x5 sheets? I've been doing four per

run.

 

Thank you for all your help. You guys have been very patient with me, particularly Jay.

 

I'm late to class, no time for spell check, sorry.

 

-Mark

[sper]

According to my testing, the intermittency effect appears to be causing failure in the

fourth exposure. This is where it first appears most noticably. Although to be safe, two

exposures is probably as far as I'd push it.

 

So I've got that out of the way! With my new testing methods my results should be quite a

bit more uniform. I plan on taking an empty paper bag and making masks I can tape on

my carriers. They'll each have a hole in a different place through which I can make

exposures. I'll plot my numbers as I get them.

-Mark

[Doctorpepe]

Hi. 

I was wondering why the current formulation did not include a small amount of Benzotriazole (as in previous formulations) to reduce the inherent fog (FB+Fog) levels to a minimum, or was it found ineffective?  Also, other highly concentrated liquid developers use a small amount of polyvinylpyrrolidone for the same purpose.  Any thoughts on these? 

Pyro imparts a unique stain concurrent with the image which is exactly what we need to add to enhance the low-density areas of the image and to enhance detail. It is most effective when there is a minimal amount of sulfite present...which is exactly what we have here!   Any thoughts to adding Catechol to the concentrate to further enhance this stain, since low sulfite also promotes the staining effect of Catechol? 

Thank you in advance.

Kevin Pernicano

San Antonio, TX

[rodeo_joe1]

On 11/16/2022 at 10:33 PM, Doctorpepe said:

I was wondering why the current formulation did not include a small amount of Benzotriazole (as in previous formulations) to reduce the inherent fog (FB+Fog) levels to a minimum, or was it found ineffective?  Also, other highly concentrated liquid developers use a small amount of polyvinylpyrrolidone for the same purpose.  Any thoughts on these? 

My first thought is that you're at least 30 years too late to be worrying about developer formulations. Almost every sensible, and insane, combination of chemicals has already been tried, and by people with far more knowledge and experience of developing chemistry than almost anyone left alive today. 

Added to that is the inaccessibility of chemicals in 'experimenter' quantities nowadays. Although there may be some old bottles of Benzotriazole stowed away somewhere (I have some.... somewhere).

Would I bother making up some 510 pyro and testing a batch with/without added restrainer? ... Er, no. Complete waste of time IMO. What would it acheive? Since I believe that some films already have an organic restrainer incorporated in the emulsion. Besides which, the crazy dilutions people use Pyro at would need a comparatively huge quantity of restrainer in the concentrate to be effective when diluted 100 fold or more. For that same reason most published Rodinal-like formulations contain no restrainer either. 

On 11/16/2022 at 10:33 PM, Doctorpepe said:

Pyro imparts a unique stain concurrent with the image which is exactly what we need to add to enhance the low-density areas of the image and to enhance detail.

Enhance detail? The stain is an oxide that diffuses away from development sites and actually obscures fine detail, such as grain structure. However, like most highly dilute developers when used with a semi-stand (low agitation) technique, edge effects are enhanced and there's a dubious acuity increase. This edge effect can look like a distinct halo around high contrast areas if overdone and with a small format negative.

Late Edit - 

WRT the halo effect. I just looked at the previous posts, and the 2nd example picture by John Bond shows a distinct pale outline around the tall building, centre of picture. That's the exaggerated edge effect I'm talking about, and I'm not liking it one jot. 

Edited November 18, 2022 by rodeo_joe1

[Doctorpepe]

Thanx.  Except I am one of those people who has been around for more than 30 years (I'm 68) and have been tinkering with photochemistry (monochrome developers of all kinds, C-41 & E-6 as well and alt-processes, palladium, platinum, kallitype, cyanotype and carbon) for at least 40 of my nearly 70 years. 

The smallest format I use in film is 120, otherwise using 4x5, 5x7 & 8x10.  I sold my custom-made (by me) 11x14 some years ago as it was too expensive to feed.

I recently reverse engineered the original HC110 formula (since current iterations have lousy keeping qualities) and use it regularly.  I have used ABCPyro or some variant of it for years on and off, but hadn't stumbled onto this 510 pyro until recently.  The stain parallels the places where silver is deposited and the effect was used with great success to enhance sharpness and color with the now defunct Kodachrome, albeit not with pyrogallic acid.  If I play with any additives to the 510-pyro, I will report my findings to the  group and let others have at it as they wish.

Of course, I could just shoot digital, but that wouldn't be any fun now, would it!

Stay well, all.