Red Admiral on Oxford Ragwort

Red admirals (Vanessa atalanta) are notoriously difficult to photograph because their plumage ranges from pure white to such a deep chocolate brown that it is virtually black.

If you expose for the dark shadows, then not only do the white highlights get blown (especially in bright sunlight) but the bands of red-orange finish up looking more yellow-orange.

The secret is to expose for the mid-tones, maybe even under-exposing by 1/3 or 2/3 stop, to retain some detail in the whites. That is followed by a treatment known as 'tone mapping' which leaves the mid-tones whilst expanding the range of visible tones in both the highlights and the shadows.


Tone mapping is part of the process involved in HDR imaging but is simpler and is applied to only a single image.

I learned the method from an on-line tutorial but here it is in summary.

1) Make a duplicate layer
2) Apply Gaussian blur with a radius of one tenth of the average image dimension (eg 350 for an image 4000 x 3000 pixels)
3) Convert to monochrome (de-saturate)
4) Convert to negative (invert)
5) Set the layer opacity to 75%
6) Set the blend mode to 'Soft Light'

That's it.
Increase the effect by duplicating the layer and fine-tune by adjusting the opacity up or down.