Timeline for How to cope with high contrast?
Current License: CC BY-SA 2.5
10 events
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| Jan 27, 2011 at 1:12 | comment | added | thomasrutter | The 12- or 14-bit values of RAW don't give you the benefit you may think they do, because JPEG's 8-bit values have already been gamma corrected, while RAW's values require gamma correction. Gamma correction means the darkest parts are afforded more depth, to closely match the way we see. Nick's statement about the first 10 in JPEG equalling the first 640 in RAW is therefore wrong. In reality the first 10 values in JPEG probably only represent not many more than that in RAW. RAW needs its higher bit depth just to be able to match JPEG after correction. | |
| Jan 25, 2011 at 23:26 | comment | added | Nick Bedford | A 14-bit RAW image contains 64 times the amount of detail than a JPEG. That is crucial when working with darker photos where you wish to make that detail visible. In a JPEG if the pixel value is less than 10 (out of 255), that could actually represent anywhere from 0 to 640 in a RAW pixel value. This detail allows a shadowy pixel to be brought up in exposure without significant compromise to it's aesthetics. That being said, JPEG is tone curved and RAW is linear so it's a rough guide. | |
| Jan 25, 2011 at 22:37 | comment | added | ysap | @rm999 - since RAW is usually 12-14 bit format, as opposed to 8 but JPEG, then technically there are dozens more levels of details between any adjacent JPEG levels. It is true that the more useful sub-levels are within the shadows, but then, using local contrast techniques or local tone mapping, you benefit from sub-levels at the whole intensity range. | |
| Jan 25, 2011 at 22:26 | comment | added | rm999 | I believe RAW captures a greater dynamic range because the underexposed regions are more salvageable (because they contain more information). Someone please correct me on this if I'm wrong. | |
| Jan 25, 2011 at 22:23 | comment | added | Nick Bedford | Yes, but you never get to do anything with that JPEG. Let's not start a RAW vs JPEG war. | |
| Jan 25, 2011 at 22:19 | comment | added | Max Sang | Raw files will be easier to manipulate, but the dynamic range of the sensor is fixed for a given ISO, so a correctly exposed and (in-camera-)processed jpeg will be as good/bad as the original raw. | |
| Jan 25, 2011 at 21:48 | comment | added | ysap | @Leonidas - In order to squeeze every bit of dynamic range in this stressful situation, I think the RAW over JPEG is certainly preferable. | |
| Jan 25, 2011 at 21:44 | comment | added | Leonidas | Don't bet on the RAW for (so much higher) dynamic range, but the rest of your arguments are valid. | |
| Jan 25, 2011 at 21:42 | history | edited | ysap | CC BY-SA 2.5 |
added 178 characters in body
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| Jan 25, 2011 at 21:37 | history | answered | ysap | CC BY-SA 2.5 |