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I just read about Exposing to the Right as a way to compensate for the way the dynamic range bracketing works. This roughly re-maps intensity values so that more "shades" of shadows are captured, but somewhat less "shades" of highlights.

But if a camera uses a LUT to spread the captured information more evenly onto the 8/10/12/etc -bit space, then a similar effect should be achieved - albeit for LUTs, the resulting image, when viewed without being post-processed, has a very specific look, with reduced contrast and range peaking around the mid-tones (unless I'm mistaken).

I guess ETTR would yield a (pre-post-processing) reduced-contrast image with histogram peaking closer to the highlights. But in this sense the two would achieve similar effects, and are employed for similar purposes. It's just the transformation function that is essentially the same (if I understand it right).

However, I'm curious about two things:

  1. What are the advantages and disadvantages of using one over the other?

  2. Is there a way to use both techniques to obtain a greater benefit over using just one approach?  (For example, shooting with an HDR camera that can do a log-based LUT recording and expose the image to the right somehow.)

My intuition says that the disadvantage comes from the non-logarithmic (?) nature of ETTR. The advantage of ETTR is its being a technique that can be easily employed on cameras without HDR/LUT capabilities. Combining the two would not help in any way (assuming an idealised scenario; e.g., one where we're not overexposing to compensate for lack of light).

  • this seems to be a video oriented question. in still photography, your choices are raw (which records data like it is produced by the sensor) or JPEG (with processing/ gamma curve applied). ETTR doesn't really make sense for JPEG. – ths Jul 23 '18 at 17:14
  • Yes, I might be misunderstanding the scenarios here, I'm not claiming I have proper knowledge of what I am talking about. It could be that ETTR is used more in stills, while HDR/LUT in video, although I saw videographers apply overexposing techniques (followed by mapping-based reduced intensities in post), which would hint at HDR/LUT + ETTR. On the other hand, I wonder why I never heard about a LUT-like approach to still photography (in theory just shooting RAW will not compensate the sensor non-linearity) - maybe cameras are doing this behind the scenes? Maybe ETTR is an outdated approach? – BogdanSorlea Jul 23 '18 at 17:52
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    Applying an LUT is a form of post-processing. There's no way to view the raw information in a raw file and see anything like what we expect a properly exposed photo to look like. Please see this answer for an example of what an "unprocessed raw file" looks like converted straight to jpeg. This answer goes into more detail about what information a raw file does and does not contain. – Michael C Jul 24 '18 at 7:55
  • I realised that I am confusing the LUT in this example with the picture profile implemented on the various cameras (e.g. shooting in V-log, s-log2, etc). I got to this confusion because as far as I remember some of these cameras have recording and/or monitoring functionality that allows applying a LUT directly in the camera. I will try to post another question with the right terminology. Or should I edit this one? – BogdanSorlea Aug 1 '18 at 13:34
  • @BogdanSorlea Please don't create a duplicate question. Edit this one. – xiota Aug 3 '18 at 23:32
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I think you're comparing oranges to apples.

ETTR is setting up a shot to make the most of the sensor's data capacity, HDR or LUT is applied after the shot and can only amend whatever data is already there.

You can use ETTR to potentially "squeeze" more data into your shot when shooting in RAW which theoretically produces a better shot.

LUTs can be applied to any shot and might improve various visual aspects of the picture, but they can't improve the detail or dynamic range because you can't add any more data once the picture has been taken.

These are different stages in the photography process so they're not really comparable.

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