Zone system and scanning

[Dan Johnels]

I am taking up 4x5 photography again after 20 years. I was practicing the Zone system back then. A lot has changed during these years, motsly due to the digital possibilities of today. I am testing T-max 400, but I would like to get some suggestions how to develop it for scanning, so that I can do some editing in Photoshop. Should I aim for a density of 1.2 even for scanning? My preliminary tests seem to show that T-max 400 is linear up to 3 or so.

Any suggestions are wellcome

[Paul Butzi]

What density range is optimum for scanning? That's a question I'm currently exploring.

So far, the answer appears to depend on which scanner you are using. And, perhaps, on the film and developer you're using.

The good news from your point of view is that one of the films I'm testing with is TMY.

Note that, from a certain point of view, 'optimum' is a minor issue. You'll get good results scanning negatives developed for printing on gelatin silver papers. That might not be optimum but I'd observe that quite a few of us are scanning our old negatives and getting excellent results.

Optimizing is probably more of an issue if you're intent on ekeing every last bit of quality out, e.g. if you're making very large prints.

www.butzi.net (http://www.butzi.net)

[Leonard Evens]

I've been scanning b/w film for several years now. The standard Zone System suggests aiming to produce a print on normal (No 2.) paper. To control the placement of zones you adjust the development of the negative. But an alternate method is to develop all your negatives the same way and control placement of the zones by choice of paper grade (or filter with multigrade paper). I've found that scanning appears to be closer to the latter system than the former system, although of course you can do it either way. Modern scanners have enough dynamic range that you don't usually have to worry about being able to handle high densities in negative film, even if you've overexposed a bit. But you can also just use the standard methods you're used to and aim for that 1.2.

The difficulty is that after scanning you don't get density directly. (You can read it in Vuescan with a little effort.) You get RGB values (which would be the same for b/w) in the range 0 to 255. The aim would be to decide how these numbers correspond visually to the zones. That would determine how the image appeared on the monitor. In addition, you would want to know how the values correspond to tones in a final print.

Before you do anything else, make sure you calibrate your monitor.

Here are some possible values you might start with to correspond to zones: (with monitor set to gamma about 2.2)

X 255, IX 245, VIII 225, VII 195, VI 165, V 130, IV 100, III 75, II 50, I 25, O 0

You probably won't like the results, but you can work from there to get values that make sense to you.

When you scan, you should primarily be interested in making sure the range of values fits nicely between 0 and 255. I find that the highest interesting values should seldom be higher than 235 and the lowest interesting values should seldom be lower than about 50. You control that by setting the white and black points. In addition, most scanning software will allow you to adjust the middle values by setting gamma. Some will allow you to adjust the entire curve relating the densities in the film to the RGB values, but usually it is better doing that in a photoeditor such as Photoshop. So it is probably enough to set the gamma (sometimes called by other names such as brightness) so that the middle values and overall contrast look about right.

Once you get the image in a photoeditor, you can use the curves control to do things that Adams could only dream of.

[Dan Johnels]

Thanks for the replies. I look forward to Paul Butzi's further investigations. I am using an Epson 3200 flatbed scanner to digitize the negatives.