Archived posting to the Leica Users Group, 2007/07/19
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Henning that is concise and informative. Thanks. I think that there were several overlapping issues being discussed. I was expressing my thoughts regarding capturing all channels rather than a grey scale image (I scan), the utility of a UV filter for reducing the effect of distance haze and the flexibility of what can be done in Photoshop if no original information is thrown away. I understand what you have explained regarding strong filter effects, good colour balance from 2000?K scenes and polarizer effects requiring a filter. That makes perfect sense. Cheers Hoppy -----Original Message----- Subject: Re: [Leica] Query re B&W photography in digital I re-read what I posted, and it's obvious I wasn't clear. So: You can't achieve most filter effects in post processing. That is it. You can approach many subtle effects, and effects that have similar results to filtering exactly the same colours as the Bayer pattern filters, but no more than that. No sharp cutoff filters can be emulated to any useful degree; no strong filters of whatever colour. You have to filter before the light hits the sensor, or film. That is why there is this whole mess with the IR/UV cutoff filters on the M8; there is no way to really handle this in post processing. Once the wrong information hits a certain sensor element, it can't be distinguished from the other information. Remember, sensor elements are only buckets that collect photons; all the information that the sensor element reports is the number of photons, not the wavelength that it came in on. If you want strong filter effects, good colour balance from 2000?K scenes, polarizer effects - use a filter. You can't get the effects through post processing. -- * Henning J. Wulff /|\ Wulff Photography & Design /###\ mailto:henningw@archiphoto.com |[ ]| http://www.archiphoto.com _______________________________________________ Leica Users Group. See http://leica-users.org/mailman/listinfo/lug for more information