I think you are mistaken about the K10D or any digital camera for that matter being able to match or surpass the dynamic range of all color films. Most of them are rated in the linear range but the color neg films do have a useful knee that still captures highlights without blowing them out and this can be post processed (expanded) to give more useful dynamic range than any digital capture currently available. There are also low contrast films especially designed for widest possible dynamic range for use with extremely contrasty scenes or situations. Lastly, with film you dont get the noise (you get grain instead) on the shadow end you do with digital but if you go to larger film formats, this grain becomes invisible which further increase the useful dynamic range of film vs digital. jco
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Godfrey DiGiorgi Sent: Monday, January 22, 2007 1:21 PM To: Pentax-Discuss Mail List Subject: Re: Film vs. Digital - not a religion On Jan 22, 2007, at 9:18 AM, Bruce Dayton wrote: > If you are shooting digital, many have said to underexpose to save the > highlights. You are correct to expose accurately for both ends of the > spectrum. The issue with digital, I think, is that the shadow areas > tend to show noise more - so it is really best to expose for the > highlights without blowing them out and then darken later, if > necessary. Proper digital exposure should be biased to come as close to saturation as possible due to the nature of the sensors' linear capture and the mathematics associated. Bruce Fraser illustrates this well in "Real World Camera Raw with Photoshop CS2", pages 6-8. So the best methodology is to set exposure for a scene's Zone IX highlights to capture the highest valued detail that you want to retain in the final image. That brings in the greatest amount of data and exploits the sensor's analog dynamic range to maximum, minimizes noise at the blackpoint threshold after gamma encoding and bayer demosaicing. Of course, proper RAW conversion for such an exposure may not be at a RAW converter's default settings ... it often takes customization of the gamma encoding curves to express all the tonal values that were captured in RGB channel space. Current digital sensor maximum dynamic range, after gamma encoding and demosaicing, is right around 10 stops with the K10D, which surpasses most film emulsions handily. Measurements I made with my *ist DS body showed that it could manage 7-9 stops (RAW format capture, dependent upon ISO setting). Some (a very few) B&W emulsions can manage between 11-13 stops of DR at the limit. No color emulsions that I know of can handle more than 8-9 stops, transparency emulsions in particular are hard pressed to handle 5-6. Godfrey -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
