Rollei Retro 400S adjustment if actually 200ISO

Assuming the Retro 400S is actually 200ISO and I expose at 200ISO and develop at 200ISO in Rodinal 1+25, is it true that I will reduce the contrast twice from exposing at 400ISO and developing at 400ISO in Rodinal 1+25? That is my main question.

I like the contrast that I have seen on rolls I exposed and developed at 400ISO (below)so maybe I should leave well enough alone. I didn't have but one or two underexposures but I usually shoot one at Sunny 16 and then one at Sunny 16 opened up another stop, so there is a bit of insurance there.

Developing at 400ISO probably is the equivalent of pushing by one stop which adds grain, but I haven't seen more grain than I can accept.

I just scan negatives and mainly view on about 11x17" work computer screens. I will shoot a roll at 200ISO/200ISO but I am wondering if I will lose too much of the contrast that I like. Probably should shoot the same scene on two cameras, using both approaches.

Thanks!

Rollei Retro has an ISO of 400. Detering from the ISO, it then becomes an exposure index (EI). I don't understand what you mean by reduce the contrast twice?? If you expose at an EI of 200, you will have to reduce the development time by an amount determined by you. If you keep the development time the same, the contrast will remain the same. If you pull back on development time for the EI 200, then of course the contrast will be reduced... but if you are working them on the computer (which cannot be discussed here as it's 100% analogue thread), you can adjust for that. Personally, I would be shooting the film for more shadow detail. I cannot stand chalk on chalkboard looking images unless it's a photograph of chalk on a chalkboard

As it’s Aviphot 200, it’s closer to EI 125 in surface contrast conditions.
To get it to 200 you need to reduce contrast in the exposure a lot somehow.

ggray79 said:

I just scan negatives and mainly view on about 11x17" work computer screens.

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So adjust contrast of the digital files as you please. The important things to look for:
* Do you have the shadow detail that you want in the negatives?
* Are the highlights not too dense for the scanner to scan without excessive noise/grain?

Keep in mind that a negative is the analog equivalent of a digital camera raw file. As long as it contains the image information that's necessary, it's all good. Don't care too much about contrast etc, because you generally set those in post processing. Since digital is incredibly agile in this respect anyway, I wouldn't worry beside the two criteria mentioned above.

PS: grain is primarily a function of the film. You want more or less grain, pick another film. Of course there's some room for variation, but it's marginal in the grander scheme of things.

TL;DR: don't worry, shoot happily.

You do NOT have to reduce development time if you expose more. If you do then all you do is reduce contrast. Exposure controls overall density, development time controls contrast. If you "overexpose" (IOW just expose more, it may be what you meant to do) and develop normally you will get more grain, and it's possible you could push highlights up onto the shoulder and reduce detail there, but that's very unlikely with any reasonable exposure and development with modern films, though I don't know about the Rollei.

I regularly expose B&W film at EIs lower than box speed, and develop normally. The only time I develop for less time is intentionally doing N- development of sheet film and, sometimes, for medium format. For MF I use a modified zone system for B&W where I have one film back for N-, one for N, and one for N+, with the same film. Modern papers are so good across the middle contrast grades that I find N-1.5 or so and N+ 1.5 or so are all the variations I need. That's with my Mamiya 645 Pro and RZ67. For my TLRs I just shoot, expose how it seems best for the scene, and develop normally.

koraks said:

So adjust contrast of the digital files as you please. The important things to look for:
* Do you have the shadow detail that you want in the negatives?
* Are the highlights not too dense for the scanner to scan without excessive noise/grain?

Keep in mind that a negative is the analog equivalent of a digital camera raw file. As long as it contains the image information that's necessary, it's all good. Don't care too much about contrast etc, because you generally set those in post processing. Since digital is incredibly agile in this respect anyway, I wouldn't worry beside the two criteria mentioned above.

PS: grain is primarily a function of the film. You want more or less grain, pick another film. Of course there's some room for variation, but it's marginal in the grander scheme of things.

TL;DR: don't worry, shoot happily.

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Contrast and speed is linked closely with film. Higher contrast will among other things mean that you have a higher probability of falling into the black hole of no shadow information. Especially with push processing since it raises contrast.

Helge said:

Higher contrast will among other things mean that you have a higher probability of falling into the black hole of no shadow information.

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No; exposure controls shadow detail to a very large extent. Contrast is determined primarily by development.

Helge said:

Especially with push processing since it raises contrast.

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No, push processing is problematic in terms of shadow detail because it reduces exposure - and then tries to make up for it (and fails) by increasing development to reach the same overall contrast range in the negative.

You actually have to reduce development (and hence, contrast) quite a lot to irretrievably lose shadow detail - especially when the film is being scanned instead of printed optically.

There are of course many more complexities and nuances we could dish up and argue about, but virtually none of those will make much of a difference in terms of what's sensible for OP to do. I think my initial comments are quite solid in this respect.

koraks said:

No; exposure controls shadow detail to a very large extent. Contrast is determined primarily by development.



No, push processing is problematic in terms of shadow detail because it reduces exposure - and then tries to make up for it (and fails) by increasing development to reach the same overall contrast range in the negative.

You actually have to reduce development (and hence, contrast) quite a lot to irretrievably lose shadow detail - especially when the film is being scanned instead of printed optically.

There are of course many more complexities and nuances we could dish up and argue about, but virtually none of those will make much of a difference in terms of what's sensible for OP to do. I think my initial comments are quite solid in this respect.

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The characteristic curve of the film determines contrast. Trying to shape that curve with development very strongly mostly results in bad tonality and missing information in one of the ends of the range.

Yes you can always fill the shadows if you don’t care about the highlights or even in extreme cases the mids.

Fast film is low contrast and slow film is higher. That is the law. And it has very few exceptions.

It’s also why film can be considered actually sped up by the combination of preflashing or latensification and push processing, because it flattens and pushes the whole curve “back” (cutting a little off the bottom range).

Underdeveloped shadows might have something in them, but they don’t have the whole range. Then you are simply getting less data and a “scientifically” worse image.
Can’t save that with curves adjustment or the most careful of scanning.

Helge said:

Underdeveloped shadows might have something in them, but they don’t have the whole range.

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Which nobody is suggesting OP to aim for, and none of the advice given carries that risk to a significant degree.

Look, I'm not saying I disagree with the nuances you're making, but ask yourself: given OP's likely experience level and use case, how relevant would you think your remarks are for their decision-making?

We can make this infinitely complicated. It's never going to help anybody.

Alright, I'm done making my point; do carry on with the technobabble if you please.

koraks said:

Which nobody is suggesting OP to aim for, and none of the advice given carries that risk to a significant degree.

Look, I'm not saying I disagree with the nuances you're making, but ask yourself: given OP's likely experience level and use case, how relevant would you think your remarks are for their decision-making?

We can make this infinitely complicated. It's never going to help anybody.

Alright, I'm done making my point; do carry on with the technobabble if you please.

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It was a response to your post.

I’d say that treating the film as ISO 125 is good advice. It will give you the most to work with.
Pushing it can be done, but since you are pushing a film that is already high contrast due to its original use case, you are pushing it (sic).