Monday, 21 May 2012

Managing Colour

The main purpose of this exercise is to correct colour casts.I have looked through my images to find a couple of pictures with what I consider to be a colour cast that needs correcting.

I shoot RAW normally so my corrections will be made in my RAW converter. This will be Lightroom 4. When I am out shooting I quite often used to leave my camera set to auto white balance. Since starting this course I now more often set the white balance at shooting time or include a grey card in the picture.

Picture 1. Below is a picture I took on a recent shoot with Catharine, cropped but without any adjustment.. The colours are noticeably cool which is particularly evident in Catharine's fore-arms and the shadow side of her face. It is also quite a dark exposure. There is a small patch of grey on the trees in the back ground which we may be able to use to help us balance this shot..

P1. 1/500 @ F1.8, ISO 100, 85mm Auto White Balance.
To work on this image I first used the white balance eye dropper to select the Gray patch on the tree towards the back. This improved things but still left the image looking 'wrong'. I then used the temperature slider by hand to adjust the white balance until I was happy with it (Picture 2). Then I upped the exposure to brighten the picture a little. The results can be seen below.

P2. The adjusted image.

Picture 3. I had trouble finding another picture with a noticeable colour cast until I came across this in my collection. The is quite an old RAW image I took when I was messing around with depth of field and close-up photography and has a massive colour cast! I can't quite remember what the circumstances were under which the image was shot although I do have the camera settings. I believe the cardamom pods were laid out on a piece of white card in front of a large window but there is obviously some colour 'pollution' coming from somewhere!

P3. 1/10 @ F5.6, ISO 100, Auto White Balance.
The area sampled for white balance.
As we can see above there is a definite pink tinge to the whole image. To work on this picture I first imported it into Light-room and took it straight into the develop module. I used the colour picker on a small area of shadow on the white card as is shown in the cutaway to the left. Balancing to this are of shadow gave a tonally correct image which was however still a little flat and dull.
To liven the photo up a bit I upped the exposure. I followed this with a touch of contrast and brought the blacks up, keeping an eye on the clipping warnings. I am sure everybody does this the same way but I bring the black (or white) up until it just starts to clip and then back it off a little.

Finally I added some mid range boost and ended up with picture 4 below.

P4. The final image.
These edits are of a technical nature that align the photographs with what we expect to see, rather than how I may wish to portray an image. It is never-the-less important to be able to control this. If you are unable to get an image to look technically correct you probably wouldn't be able to get an image to look how you wanted it to!

This exercise has been of particular interest as I have just acquired this RAW editing software. These experiments have provided me with plenty of reasons to explore it.