Originally posted by reknelb I did a comparason with the k10d shooting a properly exposed picture at 1600 iso and then shooting the same picture under exposed at 400iso. The 400 iso pushed did not look good. 1600 wasnt bad, but then it was even better after using some techniques in photoshop. I will try the same thing with my gx-1l tonight and see how the pushed 400 iso looks.
What software? It does matter..and I believe the k10 is not so good w/ push as the other Pentax line..
Quote from one of my fav authors
(link in my first post here)............................
...so you should not be able to see difference in the shadows between camera set to ISO 1600 and ISO 800, given the exposure (aperture/shutter speed/ligt) was constant between 2 shots. what you will see is the highlights being clipped one stop more in the ISO 1600 shot.
If noise is higher then the modest amount above, it is possible that ISO 400 shot 2 stops "underamplified" (that is what you refer to as "underexposed") will not show any difference from ISO 1600 shot, except for highlights, that now are 2 stops more clipped (at 1600).
now, the results can be even more interesting if in-camera amplification that performs ISO boost adds its own noise, and in substantial amounts. some experiments we run with my friends show no difference in shadows at all between ISO 200 3 stops underexposed and ISO 1600 shots.
Of course, not many raw converters will alow this, ACR is most certainly being *not* one of them. some raw converters will not show you any benefit in highlights, because they clip them the same way the camera does - but then you can use two renders from the same raw and blend them in Photoshop, like HDR.
(favorite part)..........
test your camera and workflow, determine how they tolerance "underamplification", adjust your shooting style and raw conversion methods accordingly.
..........unquote.......
Glad you checked it out. K10 handling of underexposed images is the main reason for me not considering the camera at this time....
You should post your comparisons as well.......
Now if you think about it, if the aperature and shutter speed are identical, then the light flux hitting the sensor is identical. Only difference is, do you amplify it in-camera (there really is no iso per se) or in your RAW editor???