Monday, 27 August 2012

Manual Colour Correction

You may recall that I've been troubled by the lighting when taking photographs of my paintings. Well, after a few words of advice from another artist and a bit of fiddling with the non-automatic colour correction functions in my bitmap editor (I use Corel Photobook, but she uses the freeware GIMP), I think I may have cracked it.

I used Botallack: Chimney as an example before, so here it is again:

Left to right:
  1. Uncorrected photograph
  2. Auto-white balanced photograph
  3. Manually corrected photograph. I can't tell you exactly how much I changed each parameter (it would vary for each image, anyhow), but I did do the following:
  • made it lighter
  • added a bit of yellow
  • increased the contrast 
  • increased the brightness
Here's the full image:

I think that it reflects the true image better. Of course, it depends on the calibration of my screen, but it is better than the dullness of the original and the slight garishness of the auto-white-balanced version.

I manually corrected a few other images, too (I mostly just made them a bit lighter and added yellow; I didn't change the contrast or brightness on anything except Botallack: Chimney). I haven't changed the original posts, but here they are, side-by-side with their previous versions:

Darwin's Houses. Top: original photograph. Bottom: manual correction

Iron Age Round Houses at Butser. Top: auto-white balance. Bottom: manual correction.

I may do some more fiddling with the worst offenders that are already published, at another time.


  1. I like the auto-white balance best, but then I'm seeing it through my computer screen and I know hubby and I see colours differently, so perhaps it's all subjective? Are they foxgloves in the round house one? Lovely whatever plant they are.

    1. Very subjective Beth! To my eye (and via my computer screen), the auto white balance one is rather harsh. I atually think it works quite well with Botallack: Chimney, but it isn't accurate. As for the round houses painting, I think the AWB is too much. Too pink. Decidedly garish. And definitely not accurate. I'm not sure that the manual correction is entirely right, either, mind.

      As to the flowers, they are willowherb. Very BIG willowherb. I don't think iron age people were too worried about "weeds".

    2. there are big willow herb everywhere here too, they do look pretty even though I pull them up in my own garden. Perhaps I'm just a fan of contrast? If I ever adjust photos I've taken I like them best with as much contrast as possible. Had no luck with Caerphilly castle in the rain though, might as well be in black and white!

  2. This is very interesting. I find all of the color correcting variables to be a bit overwhelming. I stick a little CMYK card (from my graphic design days) next to my drawings when I scan them, so that gives me a bit of a starting point. But there are so many variables: scanner/camera, my monitor, the viewer's monitor...agh! Not to mention printing and how the colors change depending upon the various settings, papers, etc. We spend so much time selecting just the right paint/pencil when we paint/draw, and then the smallest tweak sends things off course!

    1. Your CMYK card idea sounds useful Sarah; something to calibrate the correction against. I may have to find myself something similar.

      But yes, there are lots of variables, and I'm rather of the opinion that any photograph of a painting (with the possible exception of a specialist photographer's work) is inevitably going to be a poor imitation of the original artwork.


Tell me what you think!