Re: filmscanners: Re: VueScan 6.4.13 Available

["bjs" <bjs1@home.com>]

----- Original Message -----
From: "Roger Smith" <rsmith@unb.ca>
To: <filmscanners@halftone.co.uk>
Sent: Sunday, January 28, 2001 3:50 PM
Subject: filmscanners: Re: VueScan 6.4.13 Available


> At 12:21 PM -0500 1/22/01, EdHamrick@aol.com wrote:
> >What's new in version 6.4.13
> >
> >   * Changed "8x exposure pass" to "Long exposure pass" and
> >     made the Canon FS2710 work with this option.  Fixed
> >     several other problems with this option.
>
> I've only had a chance to try this version on 5 or 6 slides
> with my FS2710, but already I'm impressed with the remarkable
> reduction of noise in the shadow areas. It seems to be more effective
> than the multiple scan option, but I've only tried up to 4 passes.

I just tried it on my FS2710.  I agree it is very promising for the reasons
given above but 2 out of 3 tests images had a problem that rendered them
useless.

The image became extremely red/green posterized in small areas for no
apparent reason.   I suspect this bug would affect all scanners and it is
only in the deep shadows so you may not notice until later.  So I've
attached two small JPGs to demonstrate (I shifted the black level up so it
is easily visible).

I also noticed that multiple pass scanning only does a single long pass
regardless of the number of passes set.   My tests show that most of the
visible noise is still in the long pass so I think Vuescan needs the ability
to independantly set a pass count on the long pass also.  As little as two
passes makes a lot of improvement on the Canon and one starts to get killer
shadow performance !!

And since I'm here...I couldn't get any of this working on negatives with
the FS2710.  It still seems to have fundamental bugs doing the underlying
manual exposure for negatives.  Perhaps someone can verify whether manual
exposure is working for negatives and pass the result on to Ed.  I've once
again spent more time debugging Vuescan than getting any actual work done so
have to call it quits...

In any case, credit goes to Ed for innovation...once the long pass function
gets properly debugged it appears to work better than multipass scanning !!!

Byron

Attachment: CanonFS2710_normalpass.jpg
Description: JPEG image

Attachment: CanonFS2710_longpass.jpg
Description: JPEG image