Acros Dynamic Range

[Leigh]

The developer would have been Ilford DD-X, diluted 1+9 instead of the regular 1+4 @ 24°C for around 7 mins in a Jobo ATL1500, if I remember rightly.

Interesting dilution and time. I'll try it.

I've been using DD-X 1+4 for 10 mins @ 20°C in a tank with manual agitation.

Thanks very much.

- Leigh

[Adam Kavalunas]

So apparently, the developing of the film has something to do with the resulting DR? Sorry, please excuse my novice questions, but this is all pretty foreign to me. What would I expect from a lab, since I won't be developing this myself?

[Leigh]

So apparently, the developing of the film has something to do with the resulting DR? Sorry, please excuse my novice questions, but this is all pretty foreign to me. What would I expect from a lab, since I won't be developing this myself?

Read up on the Zone System. In particular read the book The Negative by Ansel Adams.

Resolving subject DR onto a negative correctly requires considerable experimentation and good process control on your part.

The chemistry will be consistent, but you must decide what you want.

With proper choice of exposure and development you can capture a wide gamut of subject ranges quite effectively.

Most labs that do 4x5 will develop to your specifications.


- Leigh

[Joanna Carter]

Interesting dilution and time. I'll try it.

I've been using DD-X 1+4 for 10 mins @ 20°C in a tank with manual agitation.

It took quite some searching to find the best time and temperature for Acros in DD-X; the best I found for 1+4 @ 20°C was 8:30 for standard contrast.

I just looked up the chart for the shot I showed; it was actually 5:30. The standard development for 1+9 @ 24°C should be 7:30.

[Leigh]

the best I found for 1+4 @ 20°C was 8:30 for standard contrast.

That's what I would expect for rotary tube processing; about 15% shorter than for tank.

I'm curious about your elevated developing temperature (24°C v. 20°C). Is that just to reduce processing time?

Thanks.

- Leigh

[Oren Grad]

So apparently, the developing of the film has something to do with the resulting DR? Sorry, please excuse my novice questions, but this is all pretty foreign to me. What would I expect from a lab, since I won't be developing this myself?

Within a pretty broad range, the developing of the film doesn't have too much to do with the SBR that the film can record. What it does affect, critically, is how easy it will be to get the information from the negative into a print, especially if you are printing in the darkroom; there's more leeway with scanning.

More specifically, if you're printing on a particular silver paper, you need to have a negative whose overall density range doesn't exceed the exposure scale of your paper. Otherwise, you'll need dodging, burning and/or masking to get the dense highlights into your print without losing shadow detail.

[Adam Kavalunas]

Thanks Oren,

I'll be scanning these negs, and printing most likely with a Lightjet. I have yet to determine which paper I will use though. Basically I just want to make sure that the DR of the scene fits on the DR of the film, and after scanning, I can make any adjustments to contrast that I want.

[Filmnut]

I've shot quite a bit of Acros, and like it very much, usually I process in Kodak Xtol, or Rodinal, but it will work nicely in most developers.
By all means do some research on the different ways to process B&W film, but at some point you just have to jump in and start to shoot, and evaluate your work from there. So, I'd suggest you go out and shoot "normal" use a developer that you can get readily, and then when you learn what that can, and cannot do, then get into the processing/exposure variations.
Keith

[Oren Grad]

I'll be scanning these negs, and printing most likely with a Lightjet. I have yet to determine which paper I will use though. Basically I just want to make sure that the DR of the scene fits on the DR of the film, and after scanning, I can make any adjustments to contrast that I want.

OK. So what you need to do is make a few exposures of a scene that's representative of the maximum brightness range you think you'll want to record, have the lab develop them, and see how your scanning goes. If the negatives easily yield a full-information scan, you're all set. If not, then you'll need to start thinking about getting your lab to pull the development, or using HDR scanning approaches to capture the full density range.

For a reasonably-developed negative, usually you shouldn't need scanning heroics. FWIW, although I do almost all of my own B&W developing, on the rare occasions over the years when I've gone with a commercial lab for one reason or another, I've almost always found that the negatives come back developed to a much higher contrast than I prefer. The only way to know where you stand will be to do a test run with your lab and see what you get.

[ic-racer]

Questions like this can be a little difficult to answer because the 'standard' 21-step wedge, of course, only shows 10.5 stops. And even in that case the exposure needs to be perfectly centered to show the 10.5 stops.