I didn't read the full reposting, so I wasn't aware it gave the info on
cleaning front surface mirror, and I didn't want to reply on my memory
as to the process, since one slip-up and the mirror is toast.
Personally, I would not over-clean a front surface mirror just because
it takes next to nothing to damage it (the fiber used in tissue can
scratch them if a bit of pressure is used), so it seems to me to avoid
the cleaning unless it is really required.
Regarding using sharpening on the scan, I'm sure you're telling it like
you see it, but I own a SS4000+, and have had it since new, and it has
always required sharpening, and so it should. Simply put, the physics
of scanning with a CCD chip require it to recapture the original
sharpness of the film image. That has nothing to do with the
cleanliness of the optics, but does have to do with the nature of
optical sampling to a CCD chip. Every CCD scanner requires unsharp
masking if the scanner has been properly designed.
In fact, unlike some scanners, the SS4000/SS4000+ have been carefully
designed to use a correctly defocused image for the CCD resolution to
avoid capturing high frequency artifacts. The unsharp masking process
then recovers some of this high frequency information lost during the
sampling process.
Choosing not to use any sharpening is certainly a personal decision, but
in so doing you are giving up some of the higher frequency information
that is within the scan and was in the original image.
I do agree with the issues you brought up regarding Kodachrome and scanning.
Art
HPA wrote:
> FWIW, I wrote the repair info posted in Jan 03 by Thomas Maugham, he was
> reprinting my earlier post. About the front surface mirror cleaning, all of
> the info is included in this post. What you need to know is to use
> denatured alcohol, use a tissue to swipe it across the mirror with no
> pressure, and do not let it touch plastic parts because it will dissolve the
> plastic. The source of this information is Bill Crispian, presently the
> oldest Leica factory trained repairman in the world (and my next-door
> neighbor). I have been doing this every month or so for a couple of years,
> my scanner works great, I don't need to sharpen my scans because the mirrors
> and lens have no fog or dust on them. Scanners accumulate haze on the
> surfaces, even when they are brand new they have some on the mirrors.
>
> Last weekend, i posted about scanning Kodachrome, however the post did not
> go through, so I am re-posting now:
>
> For Kodachrome scanning, I would like to recommend (with some reservations)
> the old Polaroid SS4000. I have used this for several years. I read the
> numerous discussions of this group and others about the Polaroid vs Nikon
> when these came out, and since 95% of my scanning is for Kodachrome I picked
> the Polaroid.
>
> POINTS IN FAVOR OF POLAROID FOR KODACHROME:
>
> DEPTH OF FOCUS: The Polaroid uses a brighter light and smaller aperture
> lens, so depth of focus is greater. Of course the DOF of any scanner may be
> insufficient for warped slides, but still the Polaroid is better. There is
> general agreement on this point by most people who have posted on the
> subject. If your slides are badly warped, you will need to use a glass
> carrier with any scanner.
>
> DIFFUSION OF LIGHT SOURCE: The Polaroid uses diffuse light, which minimizes
> dust and scratch marks on the base side of the film. The Nikon uses
> collimated light and this accentuates dust on the base side. Of course the
> Nikon has the automatic dust removal, however that does not work with
> Kodachrome because the film is opaque to IR light.
>
> EASE OF MODIFYING FILM HOLDERS: The polaroid is easy to use glass in. I
> make high quality scans, mostly from fifty year old kodachrome slides.
> Often these are very warped. I remove the film from the mount and tape one
> edge in the holder. Over that I place an anti-newton glass removed from a
> German slide mount. My scans have tack-sharp grain from corner to corner.
> Many of the slides are great to begin with, having been shot with Leicas on
> tripods, and the resulting scans can be enlarged quite a bit.
>
> COLOR ACCURACY: The Nikon uses light emitting leds, which are reputed to be
> narrower band light sources, and the result is less favorable to Kodachrome
> compared to E6 film colors. I cannot personally vouch for this, but it is
> often mentioned.
>
> I am putting up a tutorial about scanning kodachrome, and two pages are done
> so far. The first is how to date Kodachrome slides, and determine which
> ones were varnished in processing:
>
> The next page is how to remove the film from the mount here:
>
> The next two pages will be done soon, they show ultrasonic cleaning of the
> film, and mounting in a Polaroid holder with glass for scanning.
>
> One thing to keep in mind is the condition of the scanner. There are many
> mirrors and lenses inside to get dirty. Any scanner that has been left on
> the counter for a number of months will likely have quite a bit of fog and
> dust. This means you may have to sharpen your scans. I clean all mirrors
> every month. I have never needed to sharpen a scan in order to get a good
> 13x19 enlargement (unless the original slide is soft, that happens from time
> to time). Use denatured alcohol on the front surface mirrors. And cover
> the two openings with duct tape whenever you are not scanning.
>
> Good luck
> Tom Robinson
>
>
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