Craig Busch,
Regarding the relative merits of flatbed/film scanners for 120 size negatives. As others have said, it rather depends on what you intend to do with the scans.
If you only require 6 x 4 for your photo album then the less expensive flatbed scanner is probably adequate.
However if you want to make professional quality prints perhaps for larger size commercial publication then the film scanner will give much more control, at a price to match and with implications for the rest of your equipment.
That said, a friend just sends his . jpg files straight from the camera to a local printer and they appear at about 6 x 7 inches in a magazine and look just fine.
If you just want to archive your negatives. An uncompressed archive file that has the eqivalent resolution of a 120 size negative will produce a file size in the order of half a gigabyte or more. If you use one of the usual file compression methods to reduce file size, data will be lost and it can't then be called an accurate archive.
So do not discard your original negatives. There will always be a better archiving system around the corner
--
The technical considerations, as I understand it, are these: (I don't claim any expertise, just info from manufacturers web sites, eg Konica Minolta, Epson and one that was quite helpful,
<
http://www.theimage.com/photography/index.htm> If I have made mistakes I'm sure I'll soon be corrected. I havn't any practical experience of fim scanners so can't comment on the actual results obtained. I was hoping to get that from those that have.)
With a home computer set up it is probably not possible to realise the potential of the much more expensive film scanner.
The Minolta unit has a 3 line ccd sensor that will give independent control of the three primary colours.
At first sight more control may appear an advantage, but in practice it has implications for the rest of your set up.
Display monitor:
Adjusting the image. A good monitor capable of being properly set up to accurately display RGB colour is needed to be sure the hues displayed are the correct ones.
Printing
The printer has to match the printed colours to the original. The problem is that a monitor displays colour lit from behind so colours appear brighter than printed colours. The printer has a set or gamut of colours called the CYMK gamut, and this differs from the RGB monitor gamut. Converting from the RGB gamut to the CMYK gamut is the printers speciality and necessary for accurate colour reproduction.
Try entering CMYK in google or try these links:
<
http://www.microsoft.com/windowsxp/digitalphotography/gopro/ fixit/colormanagement.asp> <
http://dx.sheridan.com/advisor/cmyk_color.html>
<
http://jura.wi.mit.edu/bio/graphics/photoshop/colman.htm>
The more expensive film scanner gives more control over colour and may enable realisation of more accurate colour prints but let you in for even more expensive equipment if you want to achieve those results yourself.
File size:
Native resolution of a 120 negative.
According to the image.com web site above, using Kodak figures, resolution of film is approximately the equivalent of 5000 pixels per inch. Both flat bed and film scanner can scan at 4800 dpi so resolution shouldn't be too much of an issue.
A square inch of negative has the equiv. of 5000 x 5000 = 25 M pixels. A 120 size negative is 3.25 x 2.25 x 25 M = appx 182 M pixel equivalent. At three bytes per pixel that would give 548 MB per negative.
The Konica-Minolta web site, resolution and scan size table gives: For medium format 6 x 9 (120 size) the maximum input pixels at 4800 dpi is 10692 x 15840 pixels. (Note this achieved by interpolation so even with this film scanner the full resolution will not be achieved)
10692 x 15840 = 169,361280 Pixels or 169 M Pixels.
At three bytes per pixel, again the uncompressed file size will be approx 500 MB per negative.
File size could be reduced by the usual lossy compression methods but then it wouldn't be an accurate archive.
So if you are planning archiving your old negative album, then you will need a lot of hard disk space.
In any event keep your negatives.
Roger