Originally posted by normhead Exactly, the art of producing a decent image would be very difficult to codify. And codifying would reduce photography from an art form to series of same looking images. There are some things you never want to give up control of, and decisions about how to interpret the light you are seeing with camera is the most obvious. You do it by knowing your tool, and experience. Which is why this argument is futile. Every shortcut has it's issues ETTR is not different. That being said there will be scenes where ETTR is appropriate. It's the opportunities you miss when it's not that will be the problem.
If I had to make up an acronym for what I do it would be "Expose for the Available Light". With modern high DR cameras, expose to the left will be as appropriate in as many situations as expose too the right will be. And soemtimes "keep the highest part of the curve in the centre (or to the left or right of centre)" is the appropriate approach. I fail to see how ETTR dude came to the conclusion that adopting 1 of of those possibilities is the correct one. Possibly a function of your average colour film having half the DR of a K-1 has something to do with it. No shadow detail could be rescued from unexposed areas of film, there was nothing there.
Bottom line, if you're learning photography there are no acceptable cheats. You have to chimp, look at your histogram, then decide how to adjust accordingly. I haven't come up with any rules to help with that. IMHO, each case stands on it's own.
Exactly!
ETTR is about using exposure settings that maximize the dynamic range and minimize the noise source in the RAW data. What's clever and important about ETTR is that it explicitly optimizes exposure for data collection purposes rather than insisting that middle gray in the scene should be middle gray in the RAW or JPG file. Thus, a proper ETTR RAW file for an image of a black cat on a black couch might look like a gray cat on a gray couch in the SOOC JPG but it would enable creation of the smoothest possible final image and the recovery of the inkiest blacks in the shadows between the cat and couch.
That said, ETTR can't be applied mechanically in a lot of situations because the DR of the scene vastly exceeds the DR of the camera. The sun, in particular, is upwards of 16-17 EV brighter than the any of the sun-lit middle gray objects in the scene and those sun-lit middle gray objects might be a great many EV brighter than important objects in the shadows (e.g., picnickers under a tree). That's where the photographer's judgment comes in to determine what can be blown-out, whether the image needs to be reframed to avoid acceptable blow-outs, whether a fill-flash or reflector can illuminate the shadows, or whether the image is not worth taking because of unfavorable lighting conditions.
I also think ETTR can also create trouble if the scene has small but important highlights (e.g., colored holiday lights, the colored disk of a rising sun, etc.) that cover so few pixels that the histogram looks like it could tolerate more pushing to the right when, in reality, the colored lights are blown-white.
Shortcuts and rules can only be a starting point for getting a good image. A big part of photography is learning which shortcuts or rules can or can't be used in a given scene with a given photographic goal.