Can I use different ISO when I do stant development?

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Andrew O'Neill

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I've never had luck with full stand. I always get drag.

Yes, I do too in some images. It's very risky doing stand. Semi-stand is the safer route and pretty much the same result/effect.
 
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I apply the same development method and time even when I push it 1 or 2 stops and I get the same results as if I had used the suggested times from dev chart.
So the question is: Can I change the ISO in the same roll of film if I am going to develop it with the above stated method? If not,why? It's like developing 2 different ISO films in the same tank.

I am usually not using Kodak B&W films, but from your question, it is obvious that you get acceptable results with Tri-X or T-MAX when you underexpose by one or two stops and use the same processing time, as if you had exposed the film according to its rated EI. If that works out for you, and I have no doubt that it does, you can just as well change the exposure for each frame on one roll and there is no reason to use the same EI for an entire roll.

Over the last few months, I have done some work with a camera without a built-in light meter and on several occasions not used a light meter at all, but exposed according to my gut feeling. I am sure that my gut feeling is more than often at least one or two stops away from a correct metering (unintentional pushing and pulling), but using Rollei RPX (25, 100 and 400), stand development in Rodinal (1:100, 1 hour or 1:200, 2 hours) and vario-contrast paper, I almost without exception get easily printable negatives. I must admit though that I do have trouble scanning the negatives if they come out too thin or too dense, but I also only use a rather cheap flatbed scanner.
 

Petraio Prime

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Yes, I do too in some images. It's very risky doing stand. Semi-stand is the safer route and pretty much the same result/effect.


I agitate once per minute, two inversions with a twist. Be sure to fill your tank (almost) all the way, regardless of the number of rolls. Otherwise, you get too much movement of the developer. But do leave a tiny space at the top so that you get some movement.

Most films have little underexposure latitude, but several stops of overexposure latitude. Don't scan your negatives: print them. Otherwise, grain is unduly exaggerated.
 

Andrew O'Neill

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I agitate once per minute, two inversions with a twist. Be sure to fill your tank (almost) all the way, regardless of the number of rolls. Otherwise, you get too much movement of the developer. But do leave a tiny space at the top so that you get some movement.

Most films have little underexposure latitude, but several stops of overexposure latitude. Don't scan your negatives: print them. Otherwise, grain is unduly exaggerated.

I work with sheet film, so it's completely different procedure. I wouldn't consider "once every minute" semi-stand... :D
 

Cholentpot

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I agitate once per minute, two inversions with a twist. Be sure to fill your tank (almost) all the way, regardless of the number of rolls. Otherwise, you get too much movement of the developer. But do leave a tiny space at the top so that you get some movement.

Most films have little underexposure latitude, but several stops of overexposure latitude. Don't scan your negatives: print them. Otherwise, grain is unduly exaggerated.

It gets a flip at the halfway point. And if using plastic reels I only develop one reel at a time. I find with more than one reel even using semi I'll get drag.
 

Petraio Prime

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I work with sheet film, so it's completely different procedure. I wouldn't consider "once every minute" semi-stand... :D


Nope, it's intermittent, as recommended by film manufacturers for decades. I used to use hangers, developing in total darkness. Agitation once per minute, lifting and draining, alternating from one corner to another, as shown in the photo below.


upload_2017-5-8_14-28-3.jpeg
 
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trendland

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No question is too silly.

The short answer is the ISO of the film is what it is, changing the camera's setting will only under expose or over expose it, depending on what you set.

Lots of people recommend that you determine a personal "EI" or Exposure Index by testing and to do that, you use the manufacturer's ISO as a starting point. That allows you to determine the most effective speed for a particular film used with your equipment, processed in your choice of developer using your personal method, whatever it is. So, for example, you may determine through testing, and just shooting, that you get the best results with Tri-X exposed at 320 instead of Kodak's ISO of 400, or you might find you like the results you get exposing it at 600 (not as common, but possible).

But just because you extend development. I.E. "push" the film in processing, won't turn it into an ISO 1600 film, it's still an ISO 400 film but underexposed by 2 stops. Changing the speed mid roll (to some faster speed) just means that those shots will be underexposed compared to the others on the roll.
Great recomandation !
Nobody could explain this as simple as clear. Including myself.

with compliments
 

silveror0

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I work with sheet film, so it's completely different procedure. I wouldn't consider "once every minute" semi-stand... :D

I agree. I use only sheet film, so I heeded AA's recommendation in The Negative for semi-stand when testing my HP5+ in HC-110 . He cautioned that agitation should be carefully examined for uniformity/mottle and suggested putting the film(s) in a hanger to keep it/them submerged throughout the process, and he proposed an agitation scheme. So I chose to use highly diluted developer (1+123) with two 4x5 films in a 4-up hanger, one exposed at my previously tested EI=200 with a step wedge (in camera) & the other w/o the step wedge for a visual check of uniformity. Regarding agitation, that was done by SLOWLY raising/lowering the hanger while keeping it submerged (and prevents foaming). I've attached the plotted results, showing the agitations that had mottle as well as the one that was successful. Note the loss of film speed, indicating that an additional stop of exposure would be needed in the field when this development is indicated. Also note the Net Density zero is fb+f.

2017-05-08 (2).png
 
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Andrew O'Neill

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Nope, it's intermittent, as recommended by film manufacturers for decades. I used to use hangers, developing in total darkness. Agitation once per minute, lifting and draining, alternating from one corner to another, as shown in the photo below.


View attachment 178715

I have a bunch of hangers for 8x10. Tricky avoiding surge marks, so I gave up on them. I semi-stand in tubes, with solution right to the top. A BTZS tube can hold 1200ml of very dilute Pyrocat-HD (5ml of A and B in 1200ml water). Works beautifully.
 
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