RE: filmscanners: Negatives vs. slides in new scanners

[Alessandro Pardi <alessandro.pardi@inferentia.it>]

Rob,
the scene I chose for my test was a *bit* contrasty, still the slide was
well exposed, and details in the shadows were perfectly visible even by
holding up the slide against a window. What I meant to test wasn't the
latitude of negatives vs. slides, which needs no test, but the capability of
the scanner to read from a slide, which has a higher density than a negative
(that is, there is a bigger difference between the lightest and the darkest
values *on the film*: this was another point agreed upon in the photo.net
thread I mentioned).
I didn't use Vuescan, but I played with Nikonscan analog gain and each
Photoshop trick in my bag, still the difference between the two scans was so
big to convince me that it was an unfair match, given that the negative
already has the advantage of a wider latitude.
If anybody is interested, I can post (maybe off-list) the two jpgs of the
scans (the image was of a street partly lit by the late afternoon sun and
partly shadowy, and the slide scan has washed out colors in the sunny parts
and way darker shadows).

-----Original Message-----
From: Rob Geraghty [mailto:harper@wordweb.com]
Sent: venerdì 27 aprile 2001 00.23
To: filmscanners@halftone.co.uk
Subject: RE: filmscanners: Negatives vs. slides in new scanners


Alessandro wrote:
> After reading a long thread on photo.net, which finally stated
> that, due to Dmax values, low-end scanners work best with
> negatives and hi-end with slides, I made my own little test
> with my LS-30 by shooting the same (a bit contrasty) scene
> with Kodak Supra 100 and Fuji Provia F 100, and can confirm
> that the scan from the negative is FAR better

With a contrasty scene there will always be more detail in a neg
than a slide.  There is always (AFAIK) more exposure latitude in
neg film than slide film.

However, I am surprised that you consider Supra 100 "far better"
than Provia 100F.  My conclusion is exactly the reverse using
the same scanner for *well exposed* images.  Basing your
conclusion on a high contrast image isn't IMO reasonable,
but it depends on what you're expecting to achieve.

> Back to the question: is the (theoretical) 4.0 Dmax enough to
> have scans from slides at least as good as those from negatives?

I'd be interested to hear the responses from others with more
expensive scanners but as far as I can make out, the answer
is no - simply because the information isn't on the film.

<snip>