Anthony Farr wrote: > Another thought. Why would converting the linear CCD output to non-linear > A/D output have "not as much (good) information"? I could understand this > if the CCD was outputting digital information and arbitrarily reassigning > the values caused stairstepping type errors, but the CCD is analogue. What > it's outputting is voltages. Can't the conversion be profiled? > > Regards, > Anthony Farr > > Sure... but a log/log representation would start to have big rounding effects at each higher "stop"; in other words, it would be stair stepping right past data as it moved up the curve.
If the CCD recorded an apparent doubling in "brightness" as a doubling in voltage your scheme would work great (like film). But it doesn't. A doubling in "brightness" represents a four-fold increase in charge. (whereas your film, our eyes, etc. see this as 2x) I don't like the word brightness. It makes this discussion difficult. I really dont think Pentax has solved this problem. Even if they do have some sort of built-in gamma a/d conversion- what does it matter if it's in hardware or software once you're in the digital domain? This was all figured out years ago w/ video. References: http://www.normankoren.com/digital_tonality.html http://en.wikipedia.org/wiki/Gamma_correction -R -R >> -----Original Message----- >> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of >> > Ryan > >> Brooks >> Sent: Friday, 18 August 2006 1:22 PM >> To: Pentax-Discuss Mail List >> Subject: Re: Tonal gradation in shadows - The $67 Question? >> >> Except that the sensor is linear- if it's a CCD anyway. It's a photo >> (okay, electron) counter. If you digitize the output in a non-linear >> space, you're not getting as much (good) information as if it was a >> linear digitization. >> >> -- >> PDML Pentax-Discuss Mail List >> [email protected] >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> > > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
