Whilst I edit my photo's in Lightroom/Photoshop I always seem to keep a very stern eye on the clipping point warnings in the histogram. Even when the warning highlighting (the blue mask in Lightroom for the black point clipping) is so small in the image that the only reason I know it is there is from the histogram, I always push the black's up until the warning disappears. What I'd like to know, is if this is perfectly acceptable behaviour (bearing in mind that this can mess with the overall contrast of the image, and I like to keep most editing to a minimum), or if I'm being excessively critical and that it is OK to have some pure black in my images. My monitor is a calibrated with a spyder4 express which reports back at showing 100% sRGB colour space. Just in case it helps with anyone's answer :-) Thank you for reading and I hope to get some helpful answers/critique!
The questions are:
Are you losing detail in the black region that affects the quality of your photo? E.g. if you have some dark texture there, clipping at black would kind of make the photo more sterile, although it is much harder to notice that in black areas.
Also, black areas usually suffer from noise, and a heavy clipping at black will remove that. Note: if your image has ISO, etc. noise (or grain) overall, a perfect black area will be unrealistic.
Are you going to postprocess the image? Are you going to curve it further, adjust brightnes/contrast/etc.? If so, you should be aware of how much detail you lose in the black area.
In general, the color and contrast reproduction capability of your final medium should determine how much clipping is acceptable for you.
I usually put an Adjustment layer in Photoshop above my image that makes the visible composite 10-15% (or even more) brighter and add more contrast as well (without clipping), and edit the black areas like that. This way no scratches, picture errors go unnoticed. When I am done, and the image is pleasing for the eye, I remove the adjustment layer, and consider the black areas done. Same can be done on the white adjustments, just with a darkening and more contrast adjustment layer (watch out, as the extra contrast can create clipping if you do it excessively). When I am done with touch-ups, I create a sample final version with all postprocess effects and check if the final image is clipping too much. If so, I correct the brightness on the touched-up version. (The earlier to the original image you do adjustments, the more dynamic range and color information is kept.)
Black clipping has by no means to be a defect. For example an image that just shows the silhouette of a motive uses black clipping as a graphical effect.
However, usually one tries to avoid black clipping because of the fear of losing details in the shadows. This quickly becomes a habit one stops to think about although deep blacks can also be beneficial for certain motives. I suppose it also kind of depends on the visual style you want to achieve in your images. In analogue times especially images where the film had been pushed very much during development showed deep blacks and high contrast, resulting in a very distinctive visual style.