From: Guide Dept @ Stouffer Graphics (@)
Date: 11/14/02-06:20:54 AM Z
Thanks Joe. You've confirmed much of what I've been assuming for awhile now.
Trying to wade through manufacturers specs to decipher what the hardware can
really do and what the software is actually doing to inflat the specs can be
frustrating.
Kevin
----- Original Message -----
From: Joe <jtait@texas.net>
To: <alt-photo-process-l@skyway.usask.ca>
Sent: Wednesday, November 13, 2002 9:32 PM
Subject: Re: Another scanner related question
> Guide Dept @ Stouffer Graphics wrote:
>
> >How important is it to have a scanner with a capability to achieve a Dmax
of
> >4.2 to 4.8 when working with most films that don't even have a Dmax of
3.2?
> >Is there a real advantage?
> >
> >Thanks,
> >
> >Kevin Morris
> >
> >
> >
> >
> More dMax is a good thing, and a "0" dmin is just as important. Together
> those should indicate the dynamiuc range of the scanner, but there is
> much contention on even that point. A "0" dmin is problably impossible,
> a 4.8 dmax on a scanner costing less than 10k is probably bogus.
> Manufacturer's claims are almost always inflated.
>
> Many, if not most B&W films and their respective densities are within
> the range of most "prosumer" and up CCD film scanners. Obvioulsy depends
> on exposure, develoment, subject, etc. Slide film is where most people
> encounter problems, and even some of the best CCD scanners can have a
> lot of trouble in those dense areas. Some scanners/software use
> multi-sampling, which basically scans the film with multiple exposures
> and averages those areas. This can overcome some of the density
> problems, and improve upon some of the "noisy" shadows that a lot of
> people complain about. It can significantly add to scan times depending
> on how many times a given area is being sampled.
>
> An important point and an often overlooked one is that the effective
> density increases with the strong light source that most CCD film
> scanners use, as in the callier effect, same as in condenser enlargers.
> Even scanners that use diffusers and/or "cold cathode ray" light sources
> can quickly be maxed out.
>
> Your best bet is to demo the unit you are considering buying, or get a
> gaurentee of return if you're not satisfied, fire that puppy up and scan
> the most troublesome shots you have and look at the scan carefully in
> PS, etc.
>
> -Joe
>
>
>
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