Re: filmscanners: Medium format in a 35mm scanner?

[Jeffrey Goggin <audidudi@mindspring.com>]

>>> This is probably (another) dumb question.  I shoot 95% 35mm, but
>>> occasionally shoot 6x7cm.  I am about to buy a 35mm scanner (I have been
>>> sending film out for scans for the last year or so - Photo CD for most,
>>> drum for the most important work), but wondered if anyone has been able
>>> to reposition medium-format film into the film or transparency holder
>>> and take four scans from the film (which would then be stitched together
>>> in Photoshop).
>> 
>> This would be impossible in most dedicated film scanners.  The cheapest
>> option I can think of would be a scanner such as the Epson Photo range
which
>> can scan larger film formats.

I successfully did this with my Microtek 35t+ and seriously considered
buying a Sprintscan 35 plus and modifying it as well since it's basically
the same scanner.  If you look closely at the carrier plate assembly,
you'll see it is made in two pieces, both plastic, that are screwed
together.  I replaced the front piece with a custom-machined one made from
steel and milled slots in place of the screw holes so that I could slide it
from side-to-side.  The slide is mounted on the outside of the steel plate
(between it and the bulb) and is firmly held in place using a piece of
magnetic sign material in which I carefully cut an opening (hence the
reason why I used steel for the plate and not aluminum, which isn't
ferrous).  Because I made the opening in the steel plate large enough to
fit a 6x9 slide, the magnetic material does double-duty as a mask and I cut
separate pieces to work with 6x6, 6x7 and 6x9 slides.

Because the slide's now positioned about 3/16" forward of where it was
originally, I had to adjust the CCD position forward by a similar amount.
Fortunately, the mounting holes were slotted and the slots just long enough
so that I was able to refocus the CCD by just loosening the screws and no
disassembly was required.  I did take some time for me to get the CCD
repositioned properly, of course, but otherwise, this step was easier than
I thought it would be.

The last step is to either modify the original cover to clear the new
carrier assembly or make a replacement cover, which is the route I choose
(I actually used a cardboard box with the inside painted flat black).

Because the 35t+ is capable of scanning a square area -- claimed to be 36mm
x 36mm but actually 38mm x 38mm with my sample -- you only need to make
four scans to cover 6x6 and 6x7 slides and six passes to cover 6x9.  You do
have to remount the slide upside down after the first two (or three) passes
since I decided to keep things simple initially and didn't design the
replacement carrier so that it could be adjusted vertically as well (I
would have eventually done this but I ended up buying a different scanner
instead...) and it's important to align it as carefully as you can when
doing this since it makes the stitching process easier.

Overall, this approach worked well but was very time-consuming.
Unfortunately, the 35t+ design is now outdated and while I did consider
replacing it with a Sprintscan 35 plus and modifying it similarly, I
couldn't find one inexpensive enough to make it worthwhile.  Instead, I
recently bought a Minolta Scan Multi and so far, I'm very happy with it.
That said, I'm in the process of modifying the medium-format carrier so
that it doesn't use glass and thin plastic masks but the same magnetic
material mentioned above; I'm also in the process of modifying the 35mm
film strip carrier to let me scan 6x6 and 6x7 slides at 2820ppi in four
passes and stitch them together the way I used to do with the 35t+
(unfortunately, 6x9s won't fit without using an entirely different
approach).  If Minolta's Universal Film Holder were less expensive, I
might've been tempted to buy one of those instead but at $300+, it was out
of the question...

Anyway, if you're determined to modify a 35mm film scanner to accept
medium-format slides, it can be done but I'm not sure you wouldn't be
better off with one of the latest flatbed scanners for the same or less
money...



  

Jeff Goggin
Scottsdale, AZ