I have been a long time admirer of toned Black & White photographs. I recently read a book on this subject to see it I could use any staining techniques on digital prints (I see some tea and coffee staining experiment sin my near future). This book introduced me to the fact that some toners work from the highlights to the darks and some work from the darks to the highlights, so I thought to myself that this was a principle which I might be able to replicate in GIMP. I call it Quick N’ Dirty, as it is not an accurate representation of real wold toners, but it does produce an interesting image, in my humble opinion.
The original photo is of Cullahill castle in County laois, Ireland. It has had a quick “Auto Levels” adjustment but is otherwise unchanged. Persoanlly I didn’t much care for the colours which seemed oversaturated to my eye.
1. From the “Colors”menu select “Desaturate”. As you can see I have used the “Average” option here, but feel free to experiment.
2. From the “Colors” menu I next select “Curves”. On the “Value” setting I noted that the Histogram suggested slight underexposure, as such I dragged the top of the left slightly.
3. In order to simulate a green toner acting from the darks toward the hightlights I once again opened the “Curves” dialog. This time I selected the “Green Channel”. I mouseclicked in the centre of the curve (Straight line at this point) to add a n anchor point, I then dragged the bottom half of the curve upward to add green to the darker tones.
4. In order to simulate a blue toner acting from the highlight to the darks I again opened the “Curves” dialog and this time I select the “Blue Channel”. I again added an anchor point in the centre, but this time I want to drag the top half of the curve upward to add blue to the highlights (the sky in this case). Note that the curve is not as smooth as the one I used for green, this is because I noticed that the darker area in thetop left corner of the phot was not being affected, so I skewed the curve a little to counteract this.
5. I was going to call it a day at this point, when I asked myself “how would a more purple sky look?”. So back to the “Curves” dialog again, select the “Red Channel”, add a central anchor point and drag the upper portion of the curve upward to add a little red to the highlights. That’s about it, Sharpen and save it off. This effect may not be everyone’s cup of tea but I like the resulting image and it was fun to do.