Sharponess of 1640SU scans

[fred]

Archived from groups: alt.comp.periphs.scanner (More info?)

Hi,
Probably a dumb question but I have been using a 1640SU scanner to scan 6X6
cm negatives with mixed results. The results seemed to lack sharpness or
seem out of focus although improve with lots of unsharp mask. Recently I
tried placing the negative directly on the glass and the results seemed a
lot better. Is this a reasonable thing to do or am I fooling myself.

Thanks for any advice

Tim

 

[Guest]

Archived from groups: alt.comp.periphs.scanner (More info?)

In article <DOidnZp68IDIbXrfRVnyhg@pipex.net>, fred <tsfed@fsnet.co.uk>
writes
>Hi,
>Probably a dumb question but I have been using a 1640SU scanner to scan 6X6
>cm negatives with mixed results. The results seemed to lack sharpness or
>seem out of focus although improve with lots of unsharp mask. Recently I
>tried placing the negative directly on the glass and the results seemed a
>lot better. Is this a reasonable thing to do or am I fooling myself.
>
Might be worth checking the focus of your scanner. Place two matches on
the glass in a 'T' shape, with the end of the vertical match on top of
the horizontal match. Scan that and look at where the optimum focus is.
It may be that your particular model does indeed give optimum focus
right on the glass surface.

Bear in mind that the 1640SU, like all high resolution flatbed scanners,
is designed to have zero contrast at and above its optical resolution
limit. This eliminates aliasing when scanning at the maximum resolution
and yields a natural, analogue-like image, but it means that the detail
cannot be reproduced with pixel sharpness.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a ah heck when he's pissed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)

 

[birdman]

Archived from groups: alt.comp.periphs.scanner (More info?)

The only way to scan these film images is directly on the glass.
You will get better results if you place clear glass, preferably the type
that is treated to avoid Newton rings. over the negative. However I have
been using flatbed scanners to scan large format film images with glass from
a picture frame (make sure the glass is clean and dust free) with excellent
results for several years.