Pyro and T-grain films

[Jorge]

Which is precisely what this thread has become. As I said I hoped to get some useful information but all that is here is a bunch of vitriol. Don't bother to reply as I shall not be visiting here again.

The information is there, and this thread is about testing. If this disagrees with your opinion then this is your problem not ours.

 

[Kirk Keyes]

I think the general consensus nowadays is that "miminum time to black" is not a good method, as it is very dependant on the shape of the paper shoulder

Any test should be dependent on the paper being used. Otherwise there is not a good fit.

I am in no way suggesting that paper be left out of the testing scheme - I do agree that the test will be dependant on the paper.

Please look at this graph: http://www.photo.net/bboard/big-image?bboard_upload_id=10848684 from http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=004JZd

I hope you can see that if you print to maximum black with a paper that has a gentle shoulder, you will be losing some of the info in the paper that has the gentle shoulder vs. one that has a steeper shoulder. To quote Stephen Benskin from the thread above, "Depending on the curve shape in the film's toe, the log-H range between Fb+f and 0.10 over Fb+f varies. That means the distance between the paper's D-Max and the placement of Zone I on the paper curve also varies."

This can affect the exposure index severely - in the example I linked to above, the difference is 0.54. That's a difference of nearly two stops. Both papers have the same ISO exposure scale, but because of the shape of the shoulder, you will be radically different film speeds if you test a film on these papers using maximum black. Using 90% maximum black, you will get nearly identical results.

 

[Claire Senft]

I will take sandyking's word anyday over any scribe. I have use Pyrocat HD and PMK with both Deltal 100 and 100Tmax. Both definitely stain.

 

[Kirk Keyes]

The remarakable thing is that photographers with years of expereince and very distinguished records of exhibits, books, teaching, and writing use this outdated test right upto today. With their success one would think the method works.

There is a fair amount of variability in what makes not only an acceptable print, but even an excellent print. That's due to the artistic aspect of photography.

But if you want to make precise measurements of photographic materials and comparisons between differing materials, such as negatives with stains of different colors or properties like resolution, you will need to use some tools that are a little more precise than just eyeballing a Zone VIII subject or a Zone I print density.

I still suggest that you find someone that will use testing methods that are suitable for this kind of testing.

Kirk

 

[steve simmons]

Part Two of the test, and perhaps this is the problem in communicating, is that you then take this proof time and ei and test for zone 7 or 8. You find a sunlit wall, and using the now determined ei you exposse the wall for zone 8 (in my case). You then find the dev time that will make this tone just perceptably darker than pure paper white when proofed for the proper proof time. You now have a developing time that takes into account the shoulder of the paper with this film and film developer combination.

Yes, if you change any part of the team - film, film developer, paper and to some extent the paper developer - you may have to retest.

steve simmons

 

[Jorge]

Part Two of the test, and perhaps this is the problem in communicating, is that you then take this proof time and ei and test for zone 7 or 8. You find a sunlit wall, and using the now determined ei you exposse the wall for zone 8 (in my case). You then find the dev time that will make this tone just perceptably darker than pure paper white when proofed for the proper proof time. You now have a developing time that takes into account the shoulder of the paper with this film and film developer combination.

Yes, if you change any part of the team - film, film developer, paper and to some extent the paper developer - you may have to retest.

steve simmons

:rolleyes:

 

[johnnywalker]

The information is there, and this thread is about testing. If this disagrees with your opinion then this is your problem not ours.

Horsefeathers. This thread has nothing to do with testing. It is all about arrogance, put-downs, oneupmanship and "winning".

 

[Jorge]

Horsefeathers. This thread has nothing to do with testing. It is all about arrogance, put-downs, oneupmanship and "winning".

You should know....

 

[Donald Miller]

Horsefeathers. This thread has nothing to do with testing. It is all about arrogance, put-downs, oneupmanship and "winning".

Well, considering that, why don't you enlighten us. Take a few minutes and elaborate if you will.

 

[mikepry]

What really gets me is that you, Steve, can actually put down Jorges work. Haven't you seen the Platinum work he has posted up here? It is some of the finest you'd ever want to see (technically and artistically). It is through a knowledge of how film and developers behave via EMPIRICAL testing that he is able to produce the work that he does...consistently.

 

[Lee L]

Hijacking time:

What's your favorite antivenom?

Lee

 

[Donald Miller]

Hijacking time:

What's your favorite antivenom?

Lee

I hear Everclear works wonders...at least you won't mind or remember croaking.

 

[nworth]

I read Steve's article comparing PMK and Pyrocat-HD with great interest. Most of the information came from the pictures, however. I concluded that the PMK images had better shadow details but the Pyrocat-HD images had better highlight separations. Unfortunately, I could not tell if the differences were due to the developer or to the other parts of the process. The differences were subtle but important. With such subtle differences, careful controls are essential. Steve's controls are based on his needs for fine art photography. They are better than what most of us do. They may not be up to this sort of stuff. That said, we should recognize that the variabilities of our routine processing may mask the differences found.

 

[steve simmons]

"What really gets me is that you, Steve, can actually put down Jorges work"

I was commenting on the article he sent in about 18 months ago.

steve simmons

 

[smieglitz]

...Most of the information came from the pictures, however... Unfortunately, I could not tell if the differences were due to the developer or to the other parts of the process. The differences were subtle but important...

Given the wide variation in reproduction quality of View Camera magazine from month to month, I would not base any conclusions on pictures accompanying the testing article, especially where "subtle differences" are involved. To this end, sensitometric charts may actually provide the more accurate and potentially useful information.

As with any photographic practice, the only way to actually make a practical, valid comparison is to do your own personal testing. Relying on the information of others is as best a starting point whether that information comes from Mr. Simmons, Jorge, Sandy, Hutchins, or elsewhere.

Joe

 

[Jorge]

What really gets me is that you, Steve, can actually put down Jorges work. Haven't you seen the Platinum work he has posted up here? It is some of the finest you'd ever want to see (technically and artistically). It is through a knowledge of how film and developers behave via EMPIRICAL testing that he is able to produce the work that he does...consistently.

Thanks Mike, this is really nice of you to say. As to Simmons' opinion, well I dont have a leg to stand on, this is why I have two museum shows comming next year.....

 

[WarEaglemtn]

After reading this whole thing when it came up in a search for Pyrocat and TMax... I think I will get a digital camera.

 

[sanking]

OK, but you have to talk about digital in the Soap Box!!

Regardless of the tone of the thread, I still stand firmly by my opinion that the T-grain films such as TMAX 100 and 400 benefit as much, and in the same way, as traditional films from processing in a staining developer. They stain just as well and they tan just as well. The stain provides extra contrast for UV sensitive processes and highlight compensation with VC silver papers, and the tanning inhibits lateral migration of the developer, thereby increasing acutance, resolution, and infectious development, particulary useful in strongl back light scenes.

And that is all that really needed to have been said on the subject.

Sandy

After reading this whole thing when it came up in a search for Pyrocat and TMax... I think I will get a digital camera.