Developing Acros Question

Reading the Fujifilm Acros data sheet, for developing this film in Kodak HC-110, they list times only for ISO80. Why is this? I dont understand why there are not times for ISO100. Very confusing!

Thank you for helping clear this up.

http://www.fujifilmusa.com/shared/bin/NeopanAcros100.pdf

Different developers can achieve different speeds, and the box speed is usually the highest film speed you can reasonably achieve with the optimal developer. Of course you could be pushing the film and use higher EI, but for some reason Fuji doesn't recommend it with HC-110, or at least they don't list dev times for it. I am 100.00% sure this has nothing whatsoever to do with the fact that HC-110 is sold by Kodak, Fuji's biggest competitor

Fortunately there are other resources available to us which are more informative in this regard....

This may be as simple as "that is where Fuji found that it worked best" in their opinion. It's not a surprise that it's not at 100 as different developers do affect films in different ways. See page 3 here; http://ilfordphoto.com/Webfiles/2010628953322222.pdf , the times in bold for the various developers each create normal contrast.

Probably the combination acros with the hc-110 does not get the real 100 iso but 80. (1/3 stop).
So that means it you use a time with 100iso, you underexposure 1/3 stop.

With a different developer maybe you reach the 100 or 50... it depends.

This simply means that the 'effective' speed (properly exposed shadows) is ISO 80 when using HC110.

You should meter for 80, not sure if it makes a big difference though (that's only 1/3 stop less than ISO 100, and other inaccuracies (speeds and apertures are commonly changing in full or half stops for example)

<Edit> sound a bit redundant, there's too many people out there ;-)

Rudeofus said:

Different developers can achieve different speeds, and the box speed is usually the highest film speed you can reasonably achieve with the optimal developer. Of course you could be pushing the film and use higher EI, but for some reason Fuji doesn't recommend it with HC-110, or at least they don't list dev times for it. I am 100.00% sure this has nothing whatsoever to do with the fact that HC-110 is sold by Kodak, Fuji's biggest competitor

Fortunately there are other resources available to us which are more informative in this regard....

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Thank you very much (and everyone else too, this group is just great!). So to get ISO100, just add 30 seconds! Seems simple enough. Great help, thanks so much!

RattyMouse said:

Thank you very much (and everyone else too, this group is just great!). So to get ISO100, just add 30 seconds! Seems simple enough. Great help, thanks so much!

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Not exactly that simple.

The actual speed point may not change, but a 1/3 stop "error" is hardly a big worry on negative film.

Personally though, as a rule, if there is going to be a discrepancy, I always err on the side of extra exposure for all my negatives.

Exposure controls how much detail you get in the shadows,

Fuji is essentially suggesting that to get the same shadow detail when using HC110 you should use a bit more exposure than if you were using D76.

Extra development time is an option but it doesn't markedly change the speed point of a given film/developer combo, what it does do is change how steep the film curve is, a steeper curve (extra development/pushing/plus development) naturally prints less detail on a given paper or an adjustment in paper contrast may be needed.

Extra development may or may not be beneficial for a given shot or your photography in general. You have to decide that for yourself.

My experience supports the ISO 80 rating. In fact, as a long time HC-110 user, I can say that most of the films I develop with HC-110 require me to shoot at 2/3 to 1/2 of box speed for optimal shadow detail. My testing has even led me to shoot Efke PL100 at EI 32. This is based mainly on dil. H concentrations in hand inverted tanks.

Jonathan

If you are printing with a conventional enlarger the type of light source (condenser/diffusion) often require different film development times. I print with a condenser enlarger and find most manufacturers recommended times are just too long. As I start cutting back on times to control contrast film speed can drop 1/3 to 2/3 stop very quickly. Point is many factors can effect a films rating.

If you haven't shot the film yet I would test out the optimal speed for your equipment. Shoot a typical scene with a fair amount of shadow and mid tone detail. Meter for the mid tones. Shoot a frame at 50, 64, 80, 100, 125, 160 and develop as recommended by the data sheet. Then make a contact sheet or prints. The amount of shadow detail will be a good guide as to the proper exposure. For Acros I find 50 to 64 works best in most developers. Even at those speeds the negatives look thin, but they print nicely. This is due to the very clear film base.

Thanks for the further suggestions. At this moment I have NO printing capability and have to resort to scanning my negatives. Perhaps I can still conduct the exposure test? I am very new to this. Thank you.

If you'll be scanning do not compensate with the ISO with HC-110 as scanners IMO do better with slightly less development time for B&W negs. I always cut by dev time 10% at least as I usually scan. Dense or high contrast negs look great in hand but are very tough to scan for wide tonality.

RattyMouse said:

Thanks for the further suggestions. At this moment I have NO printing capability and have to resort to scanning my negatives. Perhaps I can still conduct the exposure test? I am very new to this. Thank you.

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Yes, doing the exposure test will be just as valid with a scanning workflow. If you post over on DPUG you will get some more advice on developing for a scanning workflow.

L Gebhardt said:

Yes, doing the exposure test will be just as valid with a scanning workflow. If you post over on DPUG you will get some more advice on developing for a scanning workflow.

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I agree with this. Getting a basic exposure and developing time is always beneficial, irrespective of whether you scan or print in a darkroom.

Acros, as Michael R points out, is pretty high contrast, especially in highlights. In combination with the very high contrast of the Fuji GA645 that the OP is using Acros definitely benefits from a bit more exposure, and then reducing development in order to keep the highlights under control.

The only thing that can truly tell us what that exposure and developing time is going to be, for ourselves, is by testing it ourselves. There are always differences between how individuals do things, the equipment they use, lighting conditions they shoot in, water quality, light meter accuracy, etc ad nauseum. A simple film speed test will do a lot for repeatable good results.

I shoot Acros full speed when I process it in Xtol. HC-110 requires a little boost in ASA.