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View Full Version : pls verify my understanding of raw and wb...



bbarlow641
11-14-2005, 04:50 PM
..or tell me I'm off base.
My understanding is that a raw file has the values that fell on the sensor, unprocessed. Therefore, the only thing that can affect a raw picture are things "in front" of the sensor, namely focus and exposure. Color correction, shifting, white balance, are all applied by the camera's software to the raw file ("cooking" it.) I should expect to do a good bit of color adjustment work on raw photos.
Focus and exposure are correctable to some minimal degree, but should be as good as you can get.
Right?
Ben

Balrog
11-14-2005, 06:39 PM
Yup, that's pretty much it.

cwphoto
12-11-2005, 10:06 PM
Yeah all right except the bit about focus, can't correct that later.

coldrain
12-12-2005, 02:33 AM
Well, that is not just it though. The camera manufacturer can do a lot of things to the "real" RAW data before it is saved. For instance they apply some filters or sharpening sometimes (or always? hard to tell) (Nikon produces more detailed, or sharper, photos with the D70/D70s/D50 than Pentax with the *istDS with the SAME sensor for instance), some apply corrections for known lenses (the D70s corrects vignetting for some lenses for instance), and Panasonic corrects CA in for instance the FZ20.

So... a lot of processing can be applied to the "RAW" data... What RAW does keep is its higher dynamic range (depending on sensor, 12 to 14 bit per colour, while JPEG stores 8 bit per colour).

But white balance is indeed stored next to the "RAW" data, as is extra sharpening.

Some cameras are better left to shoot JPEG because their RAW software delivers such miserable results that the JPEGS are much better. Pentax, Konica Minolta, Panasonic all have not so wonderful RAW software. So, unless you can find 3rd party software that supports these cameras and delivers better results, sometimes JPEG has the upperhand.

cwphoto
12-12-2005, 02:42 PM
Some cameras are better left to shoot JPEG because their RAW software delivers such miserable results that the JPEGS are much better. Pentax, Konica Minolta, Panasonic all have not so wonderful RAW software. So, unless you can find 3rd party software that supports these cameras and delivers better results, sometimes JPEG has the upperhand.

How can that be? You're saying that a process which takes the camera less than a second to do (eg; convert from RAW to JPEG) gives a better result than any RAW conversion program in post using all the time in the world? I don't think so.

coldrain
12-12-2005, 05:49 PM
How can that be? You're saying that a process which takes the camera less than a second to do (eg; convert from RAW to JPEG) gives a better result than any RAW conversion program in post using all the time in the world? I don't think so.
Use pentax or km software to see for yourself.