Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Austin
Franklin" 
<darkroom@i...> wrote:
> > Ah - I understand now.  At the test's printed size, the image
> > resolution would have
> > been
> > 2400 ppi.  Making a print from this resolution shows no moire
> > effect.  Of course, the
> > image is only ~3x3.6"...  I also tried printing a small area of
the
> > image with no resizing at a particularly bad resolution: 540ppi.
> > This print shows the
> > moire as well, although it is somewhat obscured by the softness
> > of the image at this
> > magnification.
> 
> Hi Brian,
> 
> I don't think we're in sync yet.  What size prints are you making
with your
> resampled images?  What I am suggesting is you make that same size
print as
> that, from the original scan, not resampling...  And if you are
making 3" x
> 3.6" prints, well, don't do that!  Make 8x10, and compare using
that.  Even
> 13" x 19" for that matter.  What is the source negative size BTW?
> 
> Also, are we talking color or B&W?

Austin,

Sorry if I wasn't clear in my earlier post:  this was a 6x7 TMX neg
scanned on an Epson 
3200.  The reason I initially started this test was that I noticed
some interference in 
diagonal lines in a full-resolution print ~8x10in. @ 880ppi (as you
suggested above).  By 
downsampling the image to 720ppi, the patterns were eliminated.  So,
I decided to try 
other image resolutions, to see how the printer resolution and file
resolution interacted.  
For the series of resolution tests, I used a smaller print
magnification, to illustrate the 
effect with even sharper (less magnified) detail/lines in the image. 
The print size I tested 
was ~3x3.6, which with full resolution from the scan, would have a
pixel resolution of 
2200ppi.

I think the important thing to take away from this experiment is that
it's useful to test 
ones own film/scanner/file size/print size/print driver/printer/paper
combination for 
the optimum combination.  In my case, I noticed interference (moire)
when printing file 
resolutions which are not multiples of the printers hardware
resolution.  (although the 
moire effect becomes less noticeable with higher image resolutions,
say >800ppi)

Brian