[filmscanners] Re: scanner dmax discussion

["David J. Littleboy" <davidjl@gol.com>]

"Austin Franklin" <austin@darkroom.com>
>>>>>>>>
> Because if it's linear, as you implied,

I didn't imply anything...my statement was simply how things actually work.
The assumption was, that 8 bits was sufficient for the system defined.
<<<<<<<<

OK. I missed that that was the assumption.

That appears to be the only problem here. Without that, it looked as though
you were making a mistake I used to make. Sorry.

> You wrote:
> >>>>>>>>
> If you have an 8 bit A/D, you'll get values 0-255.  Say your input to the
> A/D is -3V to +3V.  1 will represent 1/256th of 6V, and 255 will represent
> +3V.
>
> Now, you have a 16 bit A/D....SAME CCD.  You get values 0-65535.  Same A/D
> voltage input, let's say.  1 will represent 1/65536th of 6V, and
> 65535 will
> represent +3V...but...note, nothing has changed in the density range, the
> CCD is still detecting the same overall density range.
> <<<<<<<<<<

This appeared to be wrong because I missed the assumption the bit about 8
bits being adequate.

>>>>>>>>>
I believe you missed my point...  The number of bits CAN change the density
range, of course, but only if it isn't noise you are detecting.  The
assumption in my statement, obviously, was that 8 bits was sufficient to
discern down to noise.
<<<<<<<<<

Yes. I went to great effort to put that assumption back in and make the
point you were trying to make. Sigh. The wheel just got reinvented again.

David J. Littleboy
davidjl@gol.com
Tokyo, Japan


----------------------------------------------------------------------------------------
Unsubscribe by mail to listserver@halftone.co.uk, with 'unsubscribe 
filmscanners'
or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or 
body