Yes, really. No matter how you develop them, very slow films have less latitude. The reason is that the range of grain sizes is small, unlike faster films, which have a wider range of grain sizes.What you've found is the reality that a very big percentage of the claims from home darkroom users about acutance often boil down to people failing to identify intermittent vibration or alignment problems in enlargers, or using consumer grade scanners that are fundamentally unsharp.
I'd agree that XP2 Super (having printed and scanned a lot of images from it in adequately tightly controlled conditions, and in comparison to many conventional BW films and developers) is very sharp and fine grained in the highlights (just with more apparent granularity in the shadows as usual for chromogenics) - I think the main reason people don't like it is that it very firmly demonstrates the abilities of real photographic engineering to deliver an actual compensated highlight curve without mucking up the toe or midrange (assuming the end user has the baseline ability to expose it sensibly enough to get a print with decent highlights on less than G5) and they deliver their most optimal results in utterly normal C-41, not something cooked up in a garden shed by people in active denial of post-1945 photographic science. What's more amusing still is that there's an article to be found in the depths of some US photo magazine or other from the early 1980s where one of the creators of cookbook-repeated POTA derivatives for Tech Pan states that he's given up on technical films and specialist developers in favour of XP1...
The big discovery seems to have been that specific PQ ratios could do what very dilute (0.5g/l) metol only developers could do, but with the ability to be used across a much wider array of circumstances (and especially in replenished systems), with an easier choice of pH optimisations for fine grain or sharpness. And emulsions changed to maximise developer interactions for beneficial inhibition effects in the manner of the DIR couplers in chromogenic/C-41.
Not really, at least not those made with reasonably modern technology. They do tend to develop faster (and may go to higher max densities), so it's more accurate to describe some as being rather less resistant to gross user error (and some have engineered-in components to regulate the development time for this reason).
Yes, really. No matter how you develop them, very slow films have less latitude. The reason is that the range of grain sizes is small, unlike faster films, which have a wider range of grain sizes.
Basically yes, although D-23 would likely be slightly coarser grained than Perceptol and perhaps give very slightly higher emulsion speed.
Perceptol without salt isn't Perceptol - it's integral to the formula itself. And dilute D-23 doesn't give the same effect as dilute Perceptol, so there's that. Some of the comments on this thread seem like armchair quarterbacking - opinions without the experience to back it up (and I don't mean smudgy web scans as alleged "evidence" for this or that).
It wouldn't be the worst option in the world to use TMY for everything either.
I thought chromogenic XP2 was the least versatile, most characterless film I ever encountered. Soft-edged is an understatement in its case. I also wonder how long those dyes will hold up. But to each his own. I at least tried it ... kinda like the brief Tech Pan rage in pictorial photography - another mismatch - but in the opposite direction, contrast-wise.
I just tried to google the date of transition from old tmax to TMY-II and I do not trust the results I am seeing. I have a chance to get some 2008 confirmed frozen Tmax 400 in 4x5 for a really attractive price compared to current retail.
Despite my age (30) I unironically forget about the digital editing side; but shooting B&W for the sake of darkroom printing down the line.Indeed. With a hybrid "darkroom," just shoot color and convert to B&W. Outstanding. FWIW, the best color negative film Kodak ever made was a consumer product, HD400 in 24 exposure rolls. Very sharp, hence the HD.
I still have quite a few rolls frozen, although I've not shot any in a long time.
Why - the coarser grain of D23 being the result of sodium chloride but that brings us back whether sodium chloride does reduce the size of grain salt to which the answer was No hence my original question?
If the inclusion of sodium chloride is not responsible then what else causes D23 to have coarser grain than Perceptol?
Thanks
pentaxuser
The basic principle on which Perceptol and earlier Microdol are based is the addition of sodium chloride to a metol-sulfite (D-23 type) developer to produce finer grain at the slight expense of emulsion speed and traditionally acutance.
I think we’re all in agreement Perceptol is intended to produce finer grain, and that this effect will be lessened as the developer is diluted from stock strength, as it would for any solvent developer.
At issue seems to be whether or not the dilution of Perceptol enhances/produces edge effects with TMX, and if it does, why this would be unique to Perceptol. Aside from metol, sulfite and NaCl Perceptol doesn’t appear to contain additional photographically active ingredients, which would mean if it is behaving differently than say D-23 to any significant degree it would have to be the NaCl doing something special. I think Drew said he mixes his own, which is further support for the only potentially magic ingredient being NaCl.
NaCl is a relatively mild silver halide solvent and also a weak restrainer. Based on the research I’ve seen I have my doubts it can produce more meaningful TMX edge effects at 1+3 than similarly dilute D-23 etc. and I haven’t observed anything remarkable myself but anything is possible, I suppose, and there’s no point arguing about it. You also have to buy into the notion TMX isn’t a sharp film to begin with. That is perhaps worth more of an argument since it just isn’t the case.
pentaxuser,Thanks for this So from what you say Sodium Chloride( let's call it salt for simplicity) has to be responsible for Perceptol's alleged finer grain compared to D23 but why is that?
Others seem to say that salt does not have this effect Has anyone tried to make darkroom prints of the same size of identical negatives processed in Perceptol and D23 and from this, can state that the salt makes a difference?
Patrick Gainer's test was admittedly with D23 but if this is Perceptol minus the salt and we conclude that salt is the only difference between the 2 it seems a fair assumption that the test with D23 plus salt was a test with Perceptol
I had a look at his article and was hard pressed, as seemingly he wa,s to see the difference between D23 with no salt and D23 plus salt. His examples were the equivalent of two 28x42 inch prints from a 35mm film
It doesn't look from Gainer's tests that there is much of a case for salt reducing grain in Perceptol compared to D23
However if anyone can show evidence that there is a case then can they help me by showing it ?
Thanks
pentaxuser
At issue seems to be whether or not the dilution of Perceptol enhances/produces edge effects with TMX, and if it does, why this would be unique to Perceptol. Aside from metol, sulfite and NaCl Perceptol doesn’t appear to contain additional photographically active ingredients, which would mean if it is behaving differently than say D-23 to any significant degree it would have to be the NaCl doing something special. I think Drew said he mixes his own, which is further support for the only potentially magic ingredient being NaCl.
NaCl is a relatively mild silver halide solvent and also a weak restrainer. Based on the research I’ve seen I have my doubts it can produce more meaningful TMX edge effects at 1+3 than similarly dilute D-23 etc. and I haven’t observed anything remarkable myself but anything is possible, I suppose, and there’s no point arguing about it. You also have to buy into the notion TMX isn’t a sharp film to begin with. That is perhaps worth more of an argument since it just isn’t the case.
Thanks for this So from what you say Sodium Chloride( let's call it salt for simplicity) has to be responsible for Perceptol's alleged finer grain compared to D23 but why is that?
Others seem to say that salt does not have this effect Has anyone tried to make darkroom prints of the same size of identical negatives processed in Perceptol and D23 and from this, can state that the salt makes a difference?
Patrick Gainer's test was admittedly with D23 but if this is Perceptol minus the salt and we conclude that salt is the only difference between the 2 it seems a fair assumption that the test with D23 plus salt was a test with Perceptol
I had a look at his article and was hard pressed, as seemingly he wa,s to see the difference between D23 with no salt and D23 plus salt. His examples were the equivalent of two 28x42 inch prints from a 35mm film
It doesn't look from Gainer's tests that there is much of a case for salt reducing grain in Perceptol compared to D23
However if anyone can show evidence that there is a case then can they help me by showing it ?
Thanks
pentaxuser
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