I am doing a lot of black and white postprocessing lately, inspired by some of my photos, by other photos I saw and by the two books about black and white photography and post processing I read. They are writing a lot about toning black and white photographs in those books, especially with selen and sepia colors. This lead me to experiment a little bit with GIMP to try to get similar effects.
There are some toning examples and tutorials about how to tone photographs with one additional color (apart from black), and there is a GIMP script written by Alexios named “Duotone” doing this.

I took a similar approach and tried to tone black and white photographs with both, selen and sepia color, at once. The idea is to tone the darker areas with one and the brighter areas with another color keeping the completely white areas white and the black areas black. Using this technique carefully you can increase visibly the contrast of black and white photos without making them look colored. In some cases the observer won’t even notice that there is any color in the image while not looking explicitly for color. Additionally it will give a bit of old (or “darkroom”) feeling to the images.

Here my steps explained shortly for GIMP, should be easy in other applications supporting layers, masks and layer modes, too.

• Create a layer and fill it with the color you want to use for toning the brighter areas and set it to “Color” mode. Add a layer mask with the grayscale of the original photo to it.
• Create another layer, fill it with the dark toning color and set it to “Color” mode, too. Then add a layer mask to this layer using the negative of the mask used before.
• Reduce the opacity of both layers to something between 5 and 30. If you use saturated fill colors you won’t need more normally. Use it carefully.

You can modify the curves afterwards. The duotone script works with a toning curve with its hightest point in the middle and going down to 0 at the very left and the very right side. Instead of masking the darker toning color with the negative of the image, you could use the normal image there too and then apply curves like the curve used in the duotone script, but moved a little bit to the left (or to the right for the brighter toning color).

By the way, the sharpening layer used in this file is set to “Value” mode. This way you sharpen the image without touching the original layer nor the toning layers. You can download the sample GIMP xcf image file I created. And the border is created with Alexio’s Full Frame Script.

Based on the duotone script mentioned above I created a script for the GIMP which does exactly those steps. As default color values I used the more saturated colors of a selenium/sepia tone and a bluish, like cyanotype. After running this script you’ll need to adjust the opacity of the toning layers.

• tri-tone.scm

You can install it the same way as Alexios is documenting for his script.

Rolf, who is hosting the Meet The Gimp Video Podcast will perhaps include this technique in one of his shows.

Update: I corrected what I said about selenium. Selenium will give a brown-reddish tone, not a cold one. See http://en.wikipedia. … graphic_print_toning and the documentation about Ilford Multigrade Paper. Here you can find a lot of possible toning colors. Thanks, Frank, for the hint.
Although I am a bit irritated as I find a lot of bluish photos tagged with “selenium”…

Update 2: Rolf wrote about this post. From the comments there I got another link to a site of toning examples: http://www.gimpguru. … orials/SampleToning/. Great.

I took part in a little photo competition (without prices, just for fun) with the topic “structures” at a local photo club. Alltogether we had about 40 photographs to review, all of them mounted in passe-partouts. Great and really beautiful photos, you could have put all of them in a public exposition. It was hard to select only a few of them.

I presented three, two black and white photos shot with my D90 which I considered quite good, photographically.

None of them were selected. The snow photo did not get any points, the other one at least some. The third photo was selected as 8th. This was interesting for me as I only include this photo because the structures of the ice are interesting, but photographically I did not consider it worth to mention.

This was shot with my old Nikon F50 a few years ago with a Tamron 28-200 and a close up lens in the pyrenees. There where shadow in the valley so the aperture was as open as possible. The leaf is outside the sharp plane and the sharpness is dropping off visibly towards the corners. The negative was scanned with a Crystalscan negative scanner (with ICE technology) and sharpened dramatically afterwards. There is visible color noise, especially in the darker and unsharp areas, but the quality is ok to print it on A4 or even a bigger as the observation distance will be at least 0.5m.

Recently I read two books about black and white photography. One of them especially about post processing. Both of them are originally English books translated to German, Post-Production: Black and White and Working in Black & White.

There is not much text. Don’t expect to learn much about black and white photography theory here. But the photos and the descriptions are inspiring. The print is very high quality and the layout is great so it is a pleasure to read them.

The one about black and white post production is quite poor if you are doing digital photography. The traditional photography lab techniques with certain films, papers and chemicals for toning are explained quite well but the digital information is often vague and sometimes just wrong:

• Steve McLeod is saying that JPGs are loosing quality (because of artifacts) as more as you save and load them. That’s not true. Loading doesn’t cause any modification to the JPG and saving does only cause some quality loss if you increase the compression.
• Talking about scanning negatives, he mentions the ICE technology to remove dust with infrared. This book is about black and white photography, but he does not mention that ICE does not work scanning traditional black and white negative film!

I liked the second one (Working in Black & White). The photographs and the explanations are inspiring and although there is not so much theory to squeeze out, I recommend it.

Update: As Frank pointed out correctly: Of course, if you touch a JPG in any way and you save it again, you will produce more artifacts, even if you save it in the same quality. Every time the JPG compression algorithm has to be run, it will produce artifacts.