D'oh, I'm apparently receiving posts out of order. After sending this "please explain" to Ryan, THEN I find his references in my inbox. No wonder his response seemed a little sharp.
Sorry Ryan, I'll go and get my explanations from those links now. Regards, Anthony Farr > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of > Anthony Farr > Sent: Saturday, 19 August 2006 1:22 AM > To: 'Pentax-Discuss Mail List' > Subject: RE: Tonal gradation in shadows - The $67 Question? > > Not at all. In fact I don't know the working of an a/d converter beyond > that they take a stream of voltage readouts from the sensor and perform some > voodoo ceremony upon it, whereupon the voltage levels at each photosite are > assigned brightness levels of 0 - 255 for 8 bit files, or 0 - 4095 for 12 > bit files. That's the sum of my understanding of the subject. > > If someone who seems to be an expert makes an assertion without an > explanation I can: (a) totally and naively trust their opinion; or (b) ask > for some explanation. Option (a) has let me down in the past, so I choose > (b). > > So my question is; when the a/d converter assigns arbitrary brightness > levels to voltage levels, why can't they be assigned on a logarithmic scale > rather than a linear scale? Can't it have a lookup table to adapt the > numbers, or even just recalculate them on-the-fly? > > Hint - the correct answer is not "because it's not done that way" or > "because it won't work". > > Regards, > Anthony Farr > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of > Ryan > > Brooks > > Sent: Saturday, 19 August 2006 12:32 AM > > To: Pentax-Discuss Mail List > > Subject: Re: Tonal gradation in shadows - The $67 Question? > > > > Anthony Farr wrote: > > > Oh. I see. Why? > > > > > Because, you've obviously figure out something that electrical engineers > > and physicists have missed for 20 years. Congrats! > > > > -Ryan > > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
