Exposing for Darker Midtones

[Michael Heald]

Hello! I've been scanning my Tmax negatives and invariably I find that I like the images with a darker midtone value than I get with the actual negative. I shoot TMax 100 and 400 developed in a rotary drum with Tmax RS.

Would lowering the exposure adjust the midtones relative to the white and dark points? Or would that shift the entire histogram, but not the relative position of the midtone point relative to the white and dark points?

Is there a technique to darken the midtones in a negative without changing the white and dark points of a negative? Thank you and best regards.

Mike

[robc]

one method is to use select/colour range and play with fuzziness. Click on a mid tone you want to adjust and use the + eyedropper to add more mid tones together with the fuziness control. Then after clicking OK you can use select/feather to smooth the transition if required and then apply a curve or brightness/contrast to the selection. I would recommend generating a new layer from the selection before applying the curve or brightness/contrast changes. That way you can revert to original if required.

The possibilities are endless...

[Kirk Gittings]

That seems like a simple curve fix in your scanning software or in PS. What scanning software do you use? There are about three ways to do this easily in Silverfast without changing the end points.

[Henry Ambrose]

What Kirk wrote.

To make for faster experimenting scan one of your negatives at a relatively small size, perhaps 300 pixels at actual size. Save it, and save a copy to actually work on, then in "curves" pull the straight line around to see the effects. You do this by clicking on the line and holding the button while you drag that selected point on the line.

Most often an "S" curve shape will move the tones around to make them look right - like a regular print. Think about a typical H&D curve for film with a toe and shoulder - your Photoshop adjustments will look something like that but most likely with more of a bend in the middle. So bend that line around like an "S" and you'll get the image to look like what you expect. Be sure to have "preview" clicked on. Also know that you can remove points on the curve by grabbing and sliding them off the end of the graph. After a half hour or so this should start making sense.

You are working on a copy of a small file so you can't break or ruin anything (you have nothing to lose but a few minutes time) so just keep working with it. You can also set your curve in the scanning software but it'll take a lot longer to see the results so don't do that until you've played around with Photoshop and have some feel for what different curve shapes do.

[Leonard Evens]

The short answer to your question is no. The characteristic curve of the film is determined by the film type and the development. In most cases, it is fairly linear in the midtone range. If you reduce the exposure, that will lower the midtone range but it will also darken the shadows and highlights under normal development. If you increase development time, that will bring the values back up, increasing contrast in the image, but you may still miss important shadow detail. Under the Zone System, for conventional printing purposes, you adjust the exposure and development so that the full range of desired values is translated into a negative whose densities allow for easy normal printing. For scanning b/w, this is less crucial because modern scanners can easily accomodate the range of densities found in b/w negatives. But it amounts to the same thing. Exposure will determine the deepest important shadows that show detail in the negative and you can adjust contrast and the highest highlights while scanning or in your photoeditor. So development time is not quite as important as long as it is in a reasonable range.

I think what you want to do is something a bit different. If you are happy with the shadow and highlight detail, what you want to do is to vary the shape of the characteristic curve so that it is not linear in the midrange but is concave downward. Film type plays role in this. For example, Ilford films seem to be quite linear down into the shadow values while some Kodak films have a long toe. But what you want probably goes beyond that. With conventional printing, it can be difficult to do it. Fortunately, it is quite easy to adjust this sort of thing digitally using a curves tool. Some scanning software has such a control. If not, any serious photoeditor, such as the full Photoshop, will. If you don't want to splurge for that, try the Gimp (www.gimp.org). I've used it for years and am happy with the results.

[Brian Ellis]

"Is there a technique to darken the midtones in a negative without changing the white and dark points of a negative?"

No. All you can independently control in making the negative are the two end points. The midranges fall wherever they fall depending on what you do through exposure and development to control the two end points. Of course after the negative is made there are various things that can be done in the darkroom or digitally to affect the midtones independently of the two end points but not in making the original negative.

[Oren Grad]

All you can independently control in making the negative are the two end points. The midranges fall wherever they fall depending on what you do through exposure and development to control the two end points.

I think that's not quite right. With TMX in particular, the curve shape can be varied quite a bit with choice of developer.

[Al D]

I can recall seeing some photos and characteristic curves in Phil Davis' discussion image gradation in BTZS which indicated that Rodinal and T-MAX RS (can't remember the dilutions) produced midtones that were lower in value than, say, D-76.

[Brian Ellis]

"I think that's not quite right. With TMX in particular, the curve shape can be varied quite a bit with choice of developer."

If the curve shape is altered then presumably the shadows and highlights are also altered to some extent at least. Are you saying that by choice of developer one can alter say Zones IV through VI while leaving everything above and below the same from one developer to the next? If so that's surprising to me but then I've been surprised before. I'm sure it's possible to develop for different midtone values but if that's done I would have expected the highlights and shadows to be at least somewhat different as well. I understood the OP to be asking whether the midtones could be varied while leaving everything else the same. If I misunderstood my apologies.

[Kirk Gittings]

Michael, I too prefer darker midtones. See www.gittingsphoto.com. It is something I struggled with in traditional printing, but since you are scanning, there is far more and less permanent changes possible with adjustment layers, which can be altered easily for various media or simply if if your mood changes.