Archived posting to the Leica Users Group, 2009/01/15
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]I think you've misunderstood one of the most important differences between digital and film photography, and a fundamental property of digital anything. The bottom line is, if you routinely underexpose you will lose a lot of tonal information, and will introduce more noise the more you underexpose. The most important thing you can do (to give yourself the most options in post-processing) is to capture as much information on the sensor as possible, with the least amount of highlight clipping. This often (but not always) entails over-exposing. The secret sauce needs the right ingredients in the right quantities. I do not routinely under- or over-expose, instead I tend to shoot at the meter-indicated exposure. That way I tend to get a decent result if there's going to be no time to get another frame of the subject. But if there's time I check the first exposure against the histogram and adjust my exposure accordingly to expose to the right (or to the left if there seems to be too much highlight clipping). I think it's a good habit to get into, and it pays dividends when it comes to the final image quality. Bob > > Geoff, a major factor that you have not discussed is that > digital sensors > are not linear device - that is, a sensor may have better response in > certain range (e.g. midtone) than others. The conversion from > this "native" > characteristics of the sensor to the "RAW" output, is one of > the secret > sauces of the camera maker. > > On Thu, Jan 15, 2009 at 12:59 PM, Geoff Hopkinson > <hoppyman@bigpond.net.au>wrote: > > > Steve I think that there are several issues confused there. > The original > > linear information captured must be conform to the > fundamental principle. > > Half of total are used the represent the first (brightest) stop, one > > quarter > > the next, one eighth the next, one sixteenth the next etc. > Up to a reported > > 81/2 stops of maximum dynamic range for the DNG. > >