Negatives for silver chloride / Adox Lupex / AZO / Lodima - which AI has it right

[pkr1979]

Hi all,

So, Im having some fun asking AI for advice. The feedback from various services doesn't always correspond. I always assumed negatives for Adox Lupex (grade 3) were best if they were low contrast, and Claude agrees with me. However, both ChatGPT and Grok claim more contrast is needed to match the paper.

Who is right?

Cheers
Peter

 

[ezphotolessons]

Hi-Peter
SIlver Chloride papers require higher contrast, like making a "salted-paper-print"
It-seems ChatGPT and Grok were on-the-money
Here is a website link that might-anser additional-questions

Michael A. Smith and Paula Chamlee

 

[pkr1979]

Its a shame that forum is unavailable - probably lots of good info there.

 

[koraks]

SIlver Chloride papers require higher contrast, like making a "salted-paper-print"

No! Current production Adox Lupex is a very high-contrast develop-out paper (as opposed to POP salted paper); it's ca. grade 4. It requires thin negatives.
Lodima and its Kodak predecessors were made in various grades AFAIK but I think mostly 2 and 3.

Keep in mind too that the density range that's optimal for a salted paper print exceeds that of any regular grade; for salt prints, a density range of 2.1logD or even longer works best. That's grade 0/00 territory - and beyond.

 

[ezphotolessons]

apologies I should've just-said "silver-chloride-paper needs higher contrast than regular-photo-paper"

 

[koraks]

apologies I should've just-said "silver-chloride-paper needs higher contrast than regular-photo-paper"

Although that would also be doubtful, or as in the case of present-day Adox Lupex actually wrong given the ca. grade 4 contrast of that paper. So it requires thinner negatives than for most other papers, although most papers of course are VC.

 

[Lachlan Young]

Current production Adox Lupex is a very high-contrast develop-out paper (as opposed to POP salted paper); it's ca. grade 4. It requires thin negatives.
Lodima and its Kodak predecessors were made in various grades AFAIK but I think mostly 2 and 3.

The bigger issue is that people see a grade number and neither interrogate the exposure scale or characteristic curve - chloride papers were the first to really be able to achieve a genuine grade 5/ ES of 0.5 (decades of research effort went into making enlarging speed papers capable of the same exposure scale) and a visually favourable curve shape across the grades, but the distribution of some of the lower grades could wander quite considerably from what we might describe e.g. a 'normal' G2 instead being closer to a G1/ ES 1.35.

 

[pkr1979]

The bigger issue is that people see a grade number and neither interrogate the exposure scale or characteristic curve - chloride papers were the first to really be able to achieve a genuine grade 5/ ES of 0.5 (decades of research effort went into making enlarging speed papers capable of the same exposure scale) and a visually favourable curve shape across the grades, but the distribution of some of the lower grades could wander quite considerably from what we might describe e.g. a 'normal' G2 instead being closer to a G1/ ES 1.35.

What does this mean when making negatives intended for Adox Lupex at grade 3? That I actually want a higher than 'regular' CI despite the grade number?

 

[Lachlan Young]

What does this mean when making negatives intended for Adox Lupex at grade 3? That I actually want a higher than 'regular' CI despite the grade number?

Not necessarily - just do a step wedge test and it'll tell you what sort of neg you'll need, relative to your own process parameters.

 

[pkr1979]

I'm not sure I have ever done that... made a step wedge test I mean. ChatGPT and Grok knew it was a contrasty paper, but because of what you mention they argued the negative needed to be contrasty to.

 

[retina_restoration]

Hi-Peter
SIlver Chloride papers require higher contrast, like making a "salted-paper-print"

Absolutely incorrect. AZO type papers are typically too contrasty for normal negatives, as they are in the Grade 3 to Grade 4 contrast range. That means you need a FLAT negative — much less contrasty than normal.

 

[ezphotolessons]

Although that would also be doubtful, or as in the case of present-day Adox Lupex actually wrong given the ca. grade 4 contrast of that paper. So it requires thinner negatives than for most other papers, although most papers of course are VC.

apologies. I was working off my-own-4decadesexperience printing-on-1940s,1990s and 2000s AZO-Grade III. negatives with contrast-and--density that-would-yield-a 20 second exposure, like "1930s-drug-store-negatives" I sometimes re-print. I unfortunately have printed on-silver-chloride and-VC with thin-negatives, I do-not-wish-that-on-anyone. I have no experience with current ADOX or Lodima-Production-Papers. I thought everyone-used contrast-and-dense-film for silver chloride paper, maybe it is just everyone-my-teacher-taught?

It's a shame that forum is unavailable - probably lots of good info there.

I hope the-rest-of the AZO-information was-helpful at-least. I-make-a dense-negative-with-contrast, I seem to-be-a-minority.

 

[John Wiegerink]

Absolutely incorrect. AZO type papers are typically too contrasty for normal negatives, as they are in the Grade 3 to Grade 4 contrast range. That means you need a FLAT negative — much less contrasty than normal.

Paul,
I haven't started to contact print with my 8X10 camera yet, but when I do I was planning on trying this paper. After hearing about the contrast of the paper I'm beginning to have second thoughts on using it. If I have to way overexpose and under develop my 8X10 negatives just to print on Lupex I might pass on using it. The reason for passing is that I also now scan my 8X10 negatives and later, by mid-summer, plan on having my 8X10 enlarger up and running. With scanning and regular printing I'd rather have a normal contrast negative over a flat as heck negative anytime.

 

[Augustus Caesar]

Absolutely incorrect. AZO type papers are typically too contrasty for normal negatives, as they are in the Grade 3 to Grade 4 contrast range. That means you need a FLAT negative — much less contrasty than normal.

Azo came in several grades, from 1 to 5, I believe. Portrait papers (such as Ektalure) came in only one grade, which was approximately grade 3.

 

[retina_restoration]

Azo came in several grades, from 1 to 5, I believe. Portrait papers (such as Ektalure) came in only one grade, which was approximately grade 3.

It used to, yes. But no longer. Isn't Lupex the only one left? It's a very hard grade 3.

 

[retina_restoration]

Paul,
I haven't started to contact print with my 8X10 camera yet, but when I do I was planning on trying this paper. After hearing about the contrast of the paper I'm beginning to have second thoughts on using it. If I have to way overexpose and under develop my 8X10 negatives just to print on Lupex I might pass on using it. The reason for passing is that I also now scan my 8X10 negatives and later, by mid-summer, plan on having my 8X10 enlarger up and running. With scanning and regular printing I'd rather have a normal contrast negative over a flat as heck negative anytime.

John,
I produce negs for both regular silver gelatin printing and for alt processes like Kallitype and Salt. If I know that I want to print both ways, I expose two negatives appropriately and develop for each process. I don't see that as being a big deal.

 

[koraks]

If I know that I want to print both ways, I expose two negatives appropriately and develop for each process.

Best advice!

 

[pkr1979]

I have already tried some of this paper, and got more of it, and I am also having second thoughts. Suggestions on how to make negs for other alternative papers... like pt/pd, are so available - but for this Adox Lupex G3 paper there isn't.

 

[koraks]

What problem are you running into?

 

[pkr1979]

Im not sure if I run into any. Im pretty inexperienced when it comes to making darkroom prints. I think I expected it to stand out more compared to silver gelatin paper. I have printed both T-Max 400 and Ortho Plus (both developed for 'normal' contrast) - T-Max 400 does have better contrast when printed.

 

[koraks]

I think I expected it to stand out more compared to silver gelatin paper.

I understand what you mean, I think. Honestly, I don't know what the fuss is about with Lupex. When I make a decent print on it, it looks pretty much the same as what I'd make on a regular silver gel paper. It has good dmax, this has to be said, but it's not like it's miles apart from normal papers or anything.

 

[pkr1979]

I understand what you mean, I think. Honestly, I don't know what the fuss is about with Lupex. When I make a decent print on it, it looks pretty much the same as what I'd make on a regular silver gel paper. It has good dmax, this has to be said, but it's not like it's miles apart from normal papers or anything.

Yep - you understand what I mean.

 

[pkr1979]

I used the MCC developer instead of Amidol though - that might have mattered.

 

[ezphotolessons]

At-least-with- AZO grade III, I-was-taught, you need thick-dense-negatives to make full-use-of the long-tonal-range otherwise things might-be-sort-of-oh-hum. If you have the opportunity to waste--some-film over-expose it by 2stops and over-develop by 30-40% in a vigorous-developer (not ascorbic acid developers) or use MAS's PYRO as-he recommends. you might-also-need the 300WATT bulb MAS mentions in his writings because of the-negative-density, if you have a "grangier-industrial-commercial-supply" or similar big-box near you in Oslo, that is where to purchase the bulbs. Some-print-devellpers give a green-tint but it-can-be removed in selenium. If-you-go-the-Amidol-route to achieve the 3-D-effect, keep-clear of Chinese-Amidol, it-might-be-problematic. If you are projecting miniature and 120 film-with an-enlarger, you will-need the Durst Head, it is scarce and expensive. Supposedly LUPEX is what used to be called LODIMA, and since that was MAS replacement for AZO it might-be-similar to AZO but AZO will last 100 years, LODIMA ages.. no experience with LUPEX, LODIMA or the RC version of AZO that was for sale in Mexico. but YMMV

 

[Lachlan Young]

I don't know what the fuss is about with Lupex. When I make a decent print on it, it looks pretty much the same as what I'd make on a regular silver gel paper. It has good dmax, this has to be said, but it's not like it's miles apart from normal papers or anything.

50+ years ago, Azo (and equivalents like Lupex) generally had a more favourable curve shape and MTF character than many common papers on the market at the time (e.g. Kodabromide) that were being iterated through revisions to remove some environmentally problematic components that inherently aren't required in a chloride paper - technology caught up with it (and essentially made variants on the idea not just enlarging speed, but the basis of modern colour papers), but not with those who made a living out of selling doctrine in weekend workshops.