I realised as soon as I had shot this image that it was not really suitable for this exercise. Although in available light, there is window light from the left. As the exercise is about enhancement, I decided to alter the modelling on the face using the selection brush in Capture NX2 to give the impression of more even lighting.
Having reached even lighting I proceeded with the selection of the face to enhance the brightness and contrast. Again I chose the selection brush for this task. Compare the original (left) with the enhanced version.
I used the selection brush again to highlight the eyes. Although difficult to tell at this magnification, the iris is definitely clearer in the right had version.
In this final version I have used the selection brush and the colourise filter to darken the hue of Claire’s eyes. I have shown it enlarged so that the effect can be seen more clearly.
Conclusion: Having worked carefully on this exercise, I am quite happy that the enhancements that I have made are legitimate and can be justified. I think it is fine to enhance the effects of lighting to achieve a specific type of image. After all, I could have carried a reflector with me and made the same changes in camera. Changing the eye colour is not something I would do unless requested. Not that I think it is wrong, it just depends on the purpose of the image.