Originally posted by audiobomber I saw one claim of 10 stops for slides, but even that doesn't match the K-7. I hear people talk about how they can push so many stops with a K-x or K-5. I don't understand this method of photography where you have to process for basic exposure. They have a meter in the camera, Ev compensation, settings for spot, matrix and CW, an instantly available histogram; what's the justification for needing to push exposure 3-4 stops in p-p?
Let's clarify a few things... People sometimes DO this for bragging rights, but the REASON they can do is very salient. Dynamic range and high iso performance are directly related. You depend on dynamic range for detail in shadow areas. Because of the way digital sensors work, as you get lower in the shadows, you have fewer bits available for displaying detail, until the last stop only has one bit (two values) to display. If the K20D has 10 stops (I've seen this claim, but I think it's more like 8.5-9) of DR, you have actually got considerably less room than that for contrast control, because the last two stops look like ass, and break down in color noise and luminance noise.
So for contrast control, you've got about 7 stops on the K20D/K-7. With the K-5, you've got ~14 (where the last two look like ass due to luminance noise and color noise). Every stop further, you get better quality detail (because more bits are allocated to it). So if I pretend my K-5 is my K20d, and expose them for the ~8 stops and bump the contrast control ("fill light" in lightroom) slider, the K-5 image looks MUCH better. Not just a little bit. MUCH better.
So while there ARE people who will brag about the DR or High ISO performance of their cameras, the functions have a purpose, and, outside of studio situations, result in generally 'better' images ( unless you like black or noisy shadows, or blown highlights - which i'm willing to admit some people do ).
Oh, and slide films ranged between 6 and 10 stops, if I remember correctly.