filmscanners: Re:Multi-scanning; Was: My replacement 8000 is banding

[G3 <G3@his.com>]

Ed:
        Have you yet gotten one of the new Canon 4000 ppi scanners to 
include in VueScan?  In one of your earlier posts, you questioned 
whether the unit uses 2 scans or one to do the IR dust removal; have 
you gotten any information on this?  Also, is the Canon cable of 
single pass multi-scans?
        Some recent reviews have been complimentary of the Canon, 
rating it about equal to the Nikon and Polaroid 4000 units.  We're 
all very interested in getting good information on how these nice 
units compare.
                Bob

At 11:26 AM -0400 7/21/01, EdHamrick@aol.com wrote:
>In a message dated 7/21/2001 5:14:06 AM EST, artistic@ampsc.com writes:
>
>>  Actually, Nikon LS2000 and LS30 and I suspect all the newer 35mm
>>   models, at least, move the scanning "unit" (CCD, lens and lighting
>>   source and any mirrors), and not the film.
>
>Yes, every CoolScan Nikon scanner I've seen, including the
>newer ones, work this way (I haven't seen the LS-8000 yet though).
>
>>   This does probably allow for more accurate scans in multi-pass
>>   situations.
>
>I don't think there's anything intrinsicly more accurate about doing
>scans this way instead of the way the Polaroid SS4000 does it
>(moving the film carrier).  However, the key differentiator appears
>to be the way the hardware/firmware in many scanners work.
>Some scanners (like the Nikon scanners) appear to find the
>zero position once upon startup, and keep track of the stepper
>motor position to do accurate repositioning.
>
>Flatbed scanners also use stepper motors, and in theory
>could reposition accurately.  However, many scanners
>(including the SS4000 and most flatbeds) appear to use
>either a microswitch or an optical sensor to detect the
>zero position of the scanner.
>
>Using a microswitch or an optical sensor to detect the
>zero position is less accurate than the resolution of
>most scanners, which makes multi-pass multi-scanning
>impractical with these scanners.
>
>>   Probably the best manner for multi passes, is when the scanner allows
>>   for each "line" to be multi-scanned without moving anything
>
>The thing that totally amazes me is that scanner manufacturers
>like Acer (AGFA resells also) and Microtek (Polaroid resells also)
>haven't figured out that they can extend the product life of their
>scanners and make them more competitive by adding single-pass
>multi-scanning.  I'll bet it wouldn't take more than a few hours to
>add this to the firmware of most scanner manufacturers.
>
>There are a few other simple things that can be added to the
>firmware of scanners without much work.  One prediction:
>a major scanner manufacturer is going to release several
>features like this in the next year that will drive several of their
>competitors out of the scanner business.
>
>The low-end scanner business is quite competitive - witness
>AGFA's recent abandonment of the low-end scanner market
>(the Acer scanners they've been reselling).
>
>Regards,
>Ed Hamrick


--