[filmscanners] Re: New price on Flextight Photo in UK

["Arthur Entlich" <artistic-1@shaw.ca>]

Although I agree that hardware sharpening, or even non-disclosed
software sharpening, is problematic in testing for non-sharpened images
in analyzing sharpness, I question the value of looking at a
non-sharpened image in terms of determining which scanner has higher
resolution, unless there is an absolute way to determine that all
sharpening has been removed and you are seeing the "raw" CCD result
after just A/D conversion has occurred.

Since each scanner may use different hardware filtering, which is built
into the processing, and may not be fully removable, perhaps a better
test of a scanner is to simply attempt to produce the BEST scan possible
even if that requires using after scan secondary unsharp masking.  I
mean, at the end of the day (and I do realize the need for an
unsharpened image for submission before final correction or use of the
image is determined) the idea should be to have a result that provides
the sharpest image without adding distracting artifacts from the
sharpening process.

For instance, if a scanner used hardware or firmware sharpening, would
it be possible to accurately "remove" that via software during or after
the scanning process?  Can using "negative" sharpness, accurately remove
the sharpness created via electronics, to bring the image "back" to its
raw (unsharpened) state or is it more like switching a TIF to JPEG and
back to TIFF and expecting to end up with the same image one started with?

So perhaps the best comparison of scans is to have all the images
sharpened to the maximum amount they can handle without objectionable
artifacting, using whatever methods and parameters of sharpening is
required to do that, and compare those results.

Art



Moreno Polloni wrote:

>>>I think you have done a good conclusion here. If you go back in
>>>the mailing
>>>list you found what I have been written about  film flatness problems . I
>>>did last summer a test with my own 3 scanners LS2000. LS4000 and Polaroid
>>>35+ against Imacon Photo.
>>>None of them could match the Imacon scanner in sharpness and Dmax.
>>>
>
>>How do you know that any of the scanners weren't doing some sharpening
>>on their own?  I'm asking if you confirmed that they weren't...  I would
>>specifically suspect the Imacon did some sharpening...I don't know about
>>
> the
>
>>others.
>>
>
> I tested a Flextight II last year, and later found out that even with
> software sharpening set at 0, there's still a significant amount of
> sharpening applied. To turn off software sharpening, a fairly large negative
> value has to be entered, something like -100 or -200.
>
>
>
>


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