This exercise was aimed at getting us to correct a colour cast “AGAIN” so I selected an image that was taken in RAW where the white balance was set to Tungsten in the camera though the image was taken in bright sunlight. The result was a bluish cast across the image.
I could have just set the white balance in the RAW converter to daylight ot Auto and fixed the image. The result of this was a little bit orange, which is a reflection of the really bright sunlight on the day that was probably quite orangey in tone.
I decided that I would adjust this image by hand to my own taste and memory of the day.
The image had a colour temperature of 3200 as shot, so I gradually increased the temperature until it reached 5400 where it still has a faint hint of blue that brings out the sky and the grass nicely, increasing it up past 6500 probably looks more like the auto setting and is probably accurate but athletically I did not like it so I left it at 5400 the result of which is as follows:
In this exercise, the object was to take an image with obvious tone problems, and experiment with the range of sliders, available in the processing software to correct the image and present a more balanced image.
For this exercise I used the Lightroom Develop module to do the work, in normal processing I would use Photoshop for its greater array of masking and tonal tools to produce a better result. However for this exercise Lightroom was ample for the task.
Raw Image Before Treatment
As can be seen from these images, I picked an image that was shot from within a darker room through a window into a bright day-lit scene, the sky is overcast, but very bright, giving a high dynamic range to the picture. As can be seen from the screen capture, the highlights in the sky are clipping, shown by the red highlight. There is no clipping in the blacks, which would have show as a blue highlight.
I processed the image in Lightroom with the following result:
Raw Image After Treatment
Lightroom has some very good capabilities when it comes to adjusting the tonal qualities of an image.In this image I experimented with the varied options and as you can see from the screen shot applied the following adjustments:
I decreased the exposure by 0.11 stops, a very small adjustment that placed the image in the range I wanted, this was my last adjustment one all of the others had take effect to shift the whole image into the centre of the range on the histogram.
The next slider was the contrast which I bumped up by 32, this again was at the end to get the tonal range right after balancing the black and white points.
I dragged the highlights down by 89 points and the whites down by 64 points to recover the blown highlights in the sky, which was very bright.
I also increased the shadows by 30 points and the blacks by 9 points to bring up the contrast and detail in the walls.
The final image is better than the original , however if I wanted to make a proper image from this I would start again in Photoshop and apply a series of layer masks and apply detailed but different changes to each area of the image. It is a shame that there is not a great deal of detailed data in the sky areas in this image so there is not a lot to recover.
With an image like this it is difficult to apply enough change to the very bright or dar areas selectively without creating ugly halos. Photoshop has a number odd blending and feathering tools and options to help minimize this but it really comes down to the skill and patience of the operator in the end.