[Leica] More signs of the Digital Age

[jonathan at openhealth.org (Jonathan Borden)]

Frank Filippone wrote:

>OK Frank, I can accept 300 dpi as the scan resolution as some sort of
>industry standard-speak.
>
>So 300dpi times 30 inches is a scan of 10,000 pixels in one direction....
>
Yes, except that if we are dealing with 35mm film, then at some point 
you are just oversampling the individual film grains (or dye clouds as 
the case may be). That and the fact that most people don't view a 30 
inch x whatever print up close, so you can get away with 200 dpi or even 
150 dpi when as the print gets large.

> Or
>should I take the 300 dpi and multiply by the roughly 2 inches of the film
>dimension to come up with a scan of 600 pixels in 1 direction?
>  
>
No. 300 dpi is for the print.

>I think I understand that the made up pixels for the printer's head are not
>counted as yet.... right?
>  
>
That is a different issue. Just like film, the print consists of lots of 
little dots. You start out with a number of inks - between 3 and 8 - and 
the color and intensity of a given "pixel" is composed of multiple dots 
of different colors and perhaps different sizes as produced by the 
printer driver and print head.

>Yes, I was trained as an engineer, and especially in the days of slide
>rules.  So why is this digital stuff so hard?  Obfuscation?
>  
>
No you are trying to understand the description of a black box, when in 
order to really understand what is going on you need to understand the 
details of how each "black box" in the system works. At the end of the 
day digital is just (lots of) math.

Jonathan