Andy, if you don't have a reference point (ie Rodinal without salt), how do you know what the salt is doing? Is it decreasing film speed? Is it changing the shape of the characteristic curve? Etc.
Regarding the artist Thomas mentions (who uses Pyrocat, not Rodinal), I've seen no data. So if it is working, all we know is it works. We don't objectively know whether or not it works differently, and if it does work differently, in what way specifically?
Don't get me wrong, I'm not "for" or "against" stand or semi-stand agitation techniques. I'm just challenging people to think about good testing and some sort of objective data/evidence to support opinions and assertions.
Evaluating the characteristics of a specific type of film processing regimen based on prints is a tricky matter. This is because the end to end analog processes (and materials) are flexible enough that we can get excellent results in a variety of ways. This flexibility is testament to the quality of the materials we have access to, and the skills we can develop as printers. But - it is this very flexibility that makes it difficult to accurately evaluate exposure/development of negatives based on print success. Without objective measurements, it is perfectly possible for someone to think he's getting a certain result in the negative, not actually be getting that result, and still make wonderful prints. With skill and practice we learn to print the negatives we make, and they may be very consistent, but that doesn't necessarily mean we know what kind of negatives we're getting, and therefore we may not describe the results of the process properly.
I thought the OP did 4 tests (1+25, 1+25 w salt, 1+100, 1+100 w salt)
See posts #65-75 or so....
Heck Polygot have him kudos for attempting a controlled test
He's not perfect but I thought the OP's design was well thought out, executed
What shd he do to be better?
Regardless if I got the artist wrong who used X dev vs Y, there are examples of artists making great art w stand. So if they can accept a steak or two 3 out of 10 roll (what Thomas mentions) that is their deal....
I have done stand a few times and not liked it, but I can't deny a photo that looks great having used it...
Well to give one quick example, were all the test films developed to the same contrast?
Again, I'm not saying great work can't be done with stand-developed negatives. Of course it can.
All I'm suggesting is, if you were a Rodinal user and were considering using stand development, and you came across this thread, wouldn't you want to know what kind of tonality to expect? What kind of film speed to expect? What kind of local contrast compression (if any) there is? Etc.? Wouldn't you want to know how adding Sodium Chloride changed things vs straight Rodinal?
Michael is absolutely correct, especially if there is a need to quantify the findings. Developing the negatives to the same contrast is very important if you want a comparison that actually tells you exactly what differences you can expect to find. Unless you do this, it isn't a true comparison of what truly happens with the negative. It just isn't. There are too many other variables to draw any conclusions and with certainty claim a specific result.
Originally Posted by Michael R 1974
And Andy is correct too, because there are a lot of photographers who don't want to quantify their findings, they just want to try things, a little bit flying by the seat of their pants (like me), because they just care about the print, and the numbers don't matter.
Can't we have both in the same thread?
"Often moments come looking for us". - Robert Frank
"Make good art!" - Neil Gaiman
"...the heart and mind are the true lens of the camera". - Yousuf Karsh
I thought his 4 tests attempted to show the impact....maybe not to your liking (densimeter, step wedges, etc)
I am a Rodinal user, if I wanted to do stand, I wouldn't expect such a formal approach to a out side of the box approach to dev.
Everyone knows that stand dev is not recommended by the manufactures of the film and chems. No one expects a formal curve log or whatnot
Use it, if you like it and losing a roll or two is ok, give it a go....
I personally don't like it but I will not presume anyone who uses it and doesn't have "the notes I require" to be not able to talk about its virtues
See what I think happens here is some like stand others want scientific predictable outcomes
Thomas, one of Apug's greats got to 70% predictability of results, if that was good/not enough for him is his deal.....it's not your deal to say you expect 100% probability and therefore stand is not a good option....
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Yes, so long as folks are constructive. If a person requesting a more scientific model wants that, then he/she needs to propose how that could be done. Not, the results are junk because I didn't do the test. We need folks saying stuff like "send me the negs, I'll plot them..." Not ".....shesh you don't have a densimeter, these negs are not possible to eval..."
Originally Posted by Thomas Bertilsson
More constructive-group-think-community. Not no, it can't be done because you did it wrong....
I'm not an advocate of stand development, I'd not use it if adding Sodium Chloride, you get good edge sharpness with dilute developers anyway with normal agitation, and then I wouldnt use 1+100 with Sodium Chloride added.
Originally Posted by zsas
My best results with Rodinal were using it between 1+25 & 1+50 at 3 +100, and this dilution gave me superb results with normal lighting/contrast for about 20 years in all formats. One caveat I never used films faster than Agfa APX100 or Kodak's 50 EI equivalent Tmax 100.
If I were to add Chloride I'd use something similar to the 3+100 as a starting point and no way would I use stand development and such a low dilution as 1+100.
Who said it can't be done?
Originally Posted by zsas
OP wanted to experiment. All I'm saying is some more work is required if anyone wants to draw meaningful conclusions.
For example, what if in this particular case some type of reduced agitation scheme (rather than stand) gave the same results, without the risks of streaking? What kind of characteristic curve does HP5 actually produce when stand developed in Rodinal? Does anyone even know? Or do they just assume? Etc.
Apologies if I've offended anyone. As I said earlier, "Stand", "Rodinal", "Pyro" and "Amidol" are four very precarious words.
For the test to be truly valuable, the negatives would need to be shot in unvarying light (IIRC one was a bit dimmer? I would go with a flash-lit scene with lots of sharp detail and a step wedge) and developed to the same contrast index, or at least printed thereto. This is actually quite important because the usual contrast controls (amount of development and paper grade) will dramatically hide or emphasise grain. And of course it'd be nice to know if the film speeds varied with the addition of salt. Getting the CI identical across all the tested options will take probably 3 to 5 development runs for each option... and there goes a couple of whole weekends.
Originally Posted by zsas
Doing that test properly is an incredible amount of work and I don't care enough about the variations on Rodinal to do it myself. I use it at 1+50 rotary because I personally don't like the look of the highlights with stand development, so I'm not going to bother quantifying its exact performance in that regime. And similarly, I only use it on very fine films, so I don't care much about the variations in grain one can cause by adding salts or what have you.
Poly - Good points and test bias is a valid discussion point, though when I watched the OP's video, he sure shot all those a frames pretty quick....not too certain that the light changed too drastically.....but back to his theory, salt might "enhance" Rodinal.....well...in my book this is a dead theory till somone can overcome the edge streaking. I like the idea that folks are looking to mod devs to get a look. Just want to be certain that round here folks don't throw out the baby with the bath water (err salt water ) because the test model isn't perfect. I see lots of folks round here denouncing the test model for people's experiments when there is data....though not perfect. But chasing bad data we all need to ensure we check each others back about.....
I sure liked that look of the salt+1+100 for HP5+....but that edge stuff....for the birds...
Back to my Rodinal 1+25 or 50 for most my needs
Maybe Holmburgers will continue this line-a-thought or someone new to this quite old science....
I just think there is so much still to be uncovered....it's only a hundred or so years old....