I have been in some interesting debates lately on the concept of “Exposing to the right.” The idea is that digital images operate much different from film. Fully half of the information in a digital image is in the top 25% of the histogram. For that reason it makes sense to expose your images as close to the right hand side where the maximum amount of information can be captured. This is counter-intuitive for those of us who shot a lot of film and are used to the old adage to “expose for the shadows, develop for the highlights.” However, the numbers are inescapable and careful photographers everywhere are heading the new advice.
More recently I have learned another benefit to adopting this strategy. Let me show you what I am talking about. This is an image I recently shot at a botanical garden. It’s a bit underexposed, though the bulk of the histogram is in the middle. I know I can fix this up a bit by bringing the exposure up and setting the black point to to spread the tonality. Check out the way it looks after adjustments:
Now I’m liking this. It’s not the most complex composition I have done, but the color harmonies are really interesting and the white on the top of the flower is light and velvety soft. (I could go on, but I’ll spare you the details.) However, here is the part I’m getting to; a problem is beginning to show it’s ugly head. Since I am pulling the image up the histogram, from the area where there is very little information to an area where there is loads of info. So what is created in the absence of meaningful detail? You guessed it: noise! Look closely at this image, especially in the shadows where noise is usually a problem.
Ouch, that hurts. I want to work on sharpening this image especially where white flower meets dark background but efforts to increase sharpness are likely to make the noise even more noticeable. Oh, don’t worry, I have a whole bag of tricks for dealing with this situation, but the aggravating thing is that if I had exposed this correctly in the first place I would not be having to deal with this. You can argue against the “Expose to the right” strategy if you like, but I hate dealing with noise.