Digital BW, The Print

Martin writes:

> My 16-bit grayscale, 4000 dpi scans of 4x5 negs run 600+ MB. Some 16-bit
RGB
> scans top 1.8GB. So 8x10 would hit 2.4GB and 7.2GB! Actually even 600MB is
> too much to work with comfortably. I did some test printing and printed
the
> same file at 13x19 from the original 4000 dpi scan and then again from the
> same file down sampled to 2400 dpi. I could not see any difference in a
> print this size at all so I now just down sample right away. Even so by
the
> time I have an 8-bit grayscale PS file with layers the size creeps back up
> to 300 to 400 MB.
>
> If I was scanning from 8x10 I suspect I would have to scan at 2000 dpi to
> keep file sizes down to something I could even open. Further downsampling
> would probably be necessary to have a managable working file. At 1600 dpi
> you probably are at the limit current computers and PS can comfortably
> swallow. I think that you would still be amazed at the difference in
quality
> of a 1600 dpi scan from a drum scanner vs. the flatbed. The cost is
probably
> along the lines of the Zone VI enlarger. <G>

My 16-bit 4x5 grayscale scans on the Epson 1680 flatbed usually top out at
about 100MB. My 450Mhz G4 Mac seems to handle this size without a hiccup. I
usually scan my 8x10 B&W negs at 800 ppi figuring that with this size neg I
don't need anything more than that for my typical print size; generally
about 11x14, or so, on 13x19 paper. However, for best quality I should
probably be scanning at max optical density (1600) of my scanner. No doubt
that any drum scan would produce better quality than my flatbed, but the
Epson 1680 seems to do pretty well for LF work. I'm actually toying with the
idea of getting some Kami fluid, or equivalent, and trying a quasi wet-mount
directly on the glass. I've read some things about the 'net of people using
mineral oil, etc., and reporting higher resolution scans with better shadow
detail. All good things! But, then there's the cleanup. <G>

> When you do, give us some feedback on the experience. I would be very
> interested.

Will do.

> I agree! Thing weighs a ton but when I bought my system in the early 90's
it
> was an incredible bargain in that format. If it wasn't for the cost I
would
> trade for the Mamiya at this point. The 67 just offers speed and the
> possibilty of hand held shots. It works out better when I am traveling
with
> people who don't have the patience to wait while you do a view camera
shot.

Got mine in the early 90's, too. At the time, I ordered only the body,
metering prism (actually I wanted the standard prism because I always use a
spot meter - habit from all those years with LF, but they only had the prism
with the meter), and a 105/2.4 lens. Upon receipt, I tested the Pentax
optics fairly extensively against Zeiss on a Hasselblad. Though the Zeiss
glass was marginally better, the Pentax optic was no slouch! Certainly no
difference that would be discernable by even the most critical eye at my
standard print sizes. Maybe, if I was printing to billboard size? Sounds
like we got our 67s for the same reason...it's a little nerve wracking to
have the family standing around tapping their feet while you(I) set up a LF
camera and take a shot! <G> That's why, for LF work, I work alone. To this
day, I still enjoy the slow, methodical nature of working with those large
cameras.

Regards,
Alan Huntley