RE: filmscanners: Scanner resolution (was: BWP seeks scanner)

[rafeb <rafeb@channel1.com>]

At 09:11 AM 6/19/01 -0400, Austin Franklin wrote:
>
>> > One of us is hallucinating, or one of us is blind.  I sure
>> > don't see the "astonishing" difference you're talking about,
>> > even when these two images are inspected under high magnification
>> > in Photoshop.
>
>You won't see anything from "high magnification" in PS, you're looking at a
>72PPI JPEG...  I don't believe that differences the tonality, which is what
>the original comment was regarding, will change with high magnification.

The higher magnification allowed me to finally see the 
subtle differences in tonality, that's all.  With the 
high resolution of my monitor (1600 x 1200, on a 17" 
tube) the images looked pretty much the same in my 
web browser.


>> The Leafscan image looks clear and _glossy_, while the Nikon image looks
>> _flat_.
>
>I see a pretty large difference in the two on my calibrated high end 21"
>monitor. The Nikon scan looks very flat, and the color bars for the Leaf
>look correct, while the Nikons are way off.  The difference is very obvious,
>but, that difference isn't necessarily in the scanner, I would believe it
>probably has more to do with the operator than the scanner.


I agree.  Both scans are flawed.

The Leaf image has lots of pixels at codes 0, 1, etc.  Its histogram 
is butted right up against the low end.  So it has lost a good deal 
of shadow detail, as others have noted.  But overall, its contrast 
is good.  Which is what happens when you set an aggressive black 
point -- you sacrifice detail in one part of the tonal scale in 
order to benefit the rest of the image.

The Nikon image has almost no pixels below code 8.  It wastes those 
codes, and overall contrast suffers.  But it retains the shadow 
detail nicely.

The Nikon image is fixable, the Leaf image is not.

It's not rocket science.  I fully agree that operator settings 
account for 100% of the observed differences here.  It is really 
a rather poor test case.

I think it *is* worth discussing, because it might clear up some 
sloppy thinking about what might make one scanner better or worse 
than another.


rafe b.