Very cool, Quest. Another 'advanced' technique... look at the channels and choose the two with the most contrast. in this image's case it was the green and the blue (red had the least). Now, choose Image>Calculations and set it up as shown in the attached. This will create a new channel w/ the emphasized difference, then you can use this as the mask as Quest did. This will get much finer details if you continue using levels or contrast to increase the contrast in your mask alphas and multiply them together. It takes practice and experimentation, but you can mask hairs w/ this technique and isolate complicated details.