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I've been going back and forth with this. I've been looking more into working with some HDR to just get a feel for the process. I have a 500D and I'm using exposure bracketing to take 3 shots. 0, -2, and +2 EV. I've been using the HDR tool in Photoshop and wonder if just putting 3 RAW files in is giving me the best results.

I've considered trying to expand my files by going from -3 to +3 by using the RAW files to fill in the gaps and converting them to jpegs.

To summarize, is it better to work with RAW or jpegs when making HDR's. and if using jpegs is better, should I use the RAW's to get as many different exposures as possible?

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  • \$\begingroup\$ Why don't you experiment to validate or invalidate your suspicions, and post your results here? You'll be a better position in the future to answer questions yourself, and we'll benefit from not having to do the experiment ourselves to see the results. \$\endgroup\$ Commented Oct 2, 2017 at 3:25

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Raw files are definitely the best starting point for doing HDR processing (or almost any other editing). JPEGs should (in general) be used purely as a write-only format -- i.e., you produce a JPEG for viewing, possibly printing, etc., but once you've converted something to JPEG, you'd ideally never do any editing on it again. Instead, you should generally start from the original, do the editing, and produce another JPEG.

Sometimes you may have no choice but to start from a JPEG, but it's definitely not what's really preferable.

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  • \$\begingroup\$ Thanks Jerry, great advice. Do 3 RAW files have enough information at +-2EV for photoshop to do its thing? \$\endgroup\$
    – Jeremy B.
    Commented Apr 28, 2011 at 18:31
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    \$\begingroup\$ @Jeremy B. Yes, usually anyway. Your basic aim is to ensure that you have at least one exposure that maintains detail in the darkest shadow areas, one that maintains detail in the brightest areas (short of true specular highlights), and at least one every couple of stops in between. \$\endgroup\$ Commented Apr 28, 2011 at 18:34
  • \$\begingroup\$ Are you worrying about lossy compression? If so, the high-quality compression JPEG compression cameras use don't visually degrade the image. When applied once, not over and over again. \$\endgroup\$ Commented Oct 2, 2017 at 3:26
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The way HDR merging is performed, it is much easier for software to blend RAW files than JPEG images.

This is because RAW files use linear values while JPEG values are transformed by the tone-curve of the RAW->JPEG conversion process. This is different depending which Picture Style or Color Mode and image parameters used during the conversion.

Software generally analyzes the images to inverse the curve before blending values together. This introduces the possibility for inaccuracies.

That being said, the difference when using good software will be minimal. If you work with JPEG images all the time, you may not want to bother changing formats just for HDR.

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Photoshop will merge your bracketed images into a 32-bit HDR image. If you are starting with 8-bit jpgs, it requires more "guess" work than if you use the 16-bit NEF's. Itai might be right that its hard to tell the difference, but I always worry that the one case where it will be a huge difference will happen to me :-).

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