Re: [APML] Going to the Luminance side?

[lkt <tan@cox.net>]

Jason,

 This depends. Saying that CCD has more or less resolution than fine
grain film is does not mean much. You have to take into consideration
focal length, imager size, and pixel/grain size. 

 A simple example, 4x5inch Tech Pan sheet film has more resolution than
6x7cm Tech Pan simply because it is larger. To accomplish this, use a
shorter FL scope for 4x5 TP to achieve roughly the same field as 6x7cm
TP. I am assuming that your resolution is only limited by grain size and
not by optics or seeing. In this example, both cases use the exact same
type of film, namely Tech Pan, but the resolution is vastly different. 

 The use of high resolution scanner is also a non issue. There exist
scanners which are of sufficient resolution to extract all the
information out of film. Just because the scanner is 8000 dpi, it does
not mean that your film has 8000 dpi of meaningful information in it.
Case in point, a 4000 dpi scan is overkill for 3200 ASA color film but
might not be sufficient for Tech Pan processed in Technidol.

Loke



Jason Ware wrote:

> You lost me here. Why? resolution would be half in the second
> example. Nyquist holds for CCD or film. (or are you saying
> resolution is lost in the scanning process?).
> 
> Also, remember that 4000dpi scanners are reasonable now. I
> agree that CCD has more dynamic range than film, but I don't
> think a CCD has more resolution than very fine grain film
> scanned at 4000dpi (or higher in the case of a drum scan).
> 
> --
>  -Jason Ware
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