Sobotka: Why GIMP is inadequate

Posted Jan 12, 2011 12:08 UTC (Wed) by farnz (guest, #17727) [Link]

I'm rescuing bad exposures that wouldn't be usable at all if not retouched from RAW. These are not subtle improvements; I'm still not a good enough photographer to get the exposure almost right first time. If I were working with JPEGs, I'd just have to discard the exposure entirely, no matter that it's the only one where I got the composition right. It's simple things like catching a reflection of the sun in an otherwise dark composition, resulting in the swan (that then chooses to fly off) being too dark, and the duck in the shade being virtually invisible.

Now, you can argue that I should have made better use of the camera, and got an exposure where the sunlight reflecting on the metal object is overexposed, but the rest of the exposure is good, and I'd not disagree. I need to get better at using the tools I have in the field, not just fixing it up later. But the fact remains that I didn't manage that: I got an exposure with 12 bits per channel from the sensor; of those 12 bits, for most of the image, only the lowest 7 to 9 bits per channel are actually interesting data, except in the area that reflected the setting sun, where it's the top bits that are interesting data. By working in 16 bits per channel while I'm fixing my mistakes, I get to recover an otherwise lost exposure; if I were limited to 8 bpc, the major corrections I need to make will also trash the image.