On Thu, Mar 29, 2012 at 2:19 PM, Larry Colen <[email protected]> wrote: > > On Mar 29, 2012, at 2:33 AM, Bruce Walker wrote: >> >> There are two important factors to this noise being lower than you expected. > > Bruce, I'm going to have to steal these hints for my notes on low light > photography.: > >> >> The first is I've learned how to get the lowest noise out of any >> digital camera: always go for correct exposure; never increase >> brightness or exposure of any darker areas or tones of an image in >> post-processing. You have some latitude with bright and light-toned >> areas, but try not to lighten them either. Sacrifice shutter speed, >> aperture, anything; just don't underexpose hoping to correct it later. > > > In many cameras there seems to be a certain point where they no longer > increase the sensitivity in circuitry, but rather in math after the ADC. In > those cameras you don't gain anything by increasing the ISO to increase > shutter speed. > >> >> The second is that the K20D's sensor has more aesthetically pleasing >> noise than all preceding sensors that Pentax uses. So basically: live >> with its noise because you won't mind it. Reduce it with ACR or Lr NR >> a little, but don't overdo NR or you lose too much detail. > > Interesting, I found the noise characteristic of my K20 horrible. At least > in color. Lots of blue speckles. In black and white it just looked like > grainy film, but the color looked horrible.
We've chatted about this before, and I opined that perhaps your K20D was out of spec. It's also possible that my K20D is magical. :-) I doubt it though, although I think Walt believes it. ;-) But here's a thought: did you try hammering the Color NR slider in ACR or Lr? I mean crank it to 100. Colour information can be safely softened with almost no visible effect in the shot. You can also compensate for that by separately sharpening the luminance information. If you must, in order to rescue a pretty hopeless case, convert the image to Lab space (Photoshop only) and fairly aggressively sharpen the L channel. Convert back and you'll have a perceptibly sharper, though slightly noiser, image -- without extra colour noise. -- -bmw -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
