On 8 Jan 2002 at 10:54, Shel Belinkoff wrote: > OK, this is very helpful stuff, and put forth in a way that I can > understand it. Thanks! Combined with all the other input and articles, > I believe I'm finally getting a grasp on this.
I'm coming into this late (I have to sleep sometime you know), but in essence as people have said Dmax and Dmin are the maximum and min density that the scanner is capable of achieving, Dmin can not be smaller that 0 but Dmax can be larger than 4 and in cases it is. The dynamic range in any system is the difference between the noise floor of the system and the point at which it saturates, in audio the absolute dynamic range is the ration of the electronic self noise level of the system to the maximum peak levels before brick-wall clipping of the signal occurs. In an optical system it is the ration of Dmin to Dmax. An interesting example is the Imacon Flextight scanner, it has a function where it can dynamically increase the intensity of the illumination source to raise it's Dmax from 4 to 4.2 (for scanning particularly dense films), of course this in turn raises the Dmin by 0.2 so in essence even though Dmax is now 4.2 the dynamic range stays the same. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications.html - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
