Digital BW, The Print

Bob Frost wrote

> From the Epson info that I have read, the 2450 has a 6-line alternated
> sensor with 61,000 sensor elements. So the sensor elements are presumably
> spaced at 1/1200 inch with alternate lines staggered to fill in the missing
> elements by interpolation. You can't escape interpolation it seems, even at
> optical or native resolutions!

...and Alan Zinn wrote

> In the case of the E2450 I have not seen an improvement above 1800 -  I don't
> know if that is "native" or not. For what it's worth I have a review of it
> on my web page.

Which all goes to show that, when I tried to explain 'native resolution' I
assumed too much.

I don't quite agree with what Bob says, though it's a small quibble. In scanners
with multiple lines of staggered sensors I think the quality might be degraded
by each sensor sampling too large an area of the original, rather than by
interpolation.

Whatever the theory, Alan's practical observation of 'no improvement above 1800'
is the interesting one -- that is, that results are better than you'd get with a
single 1200 spi sensor, but not as good as a 'real' 2400 spi one.

Still, in comparison with its elders and betters, the Epson 2450 sounds like
terrific value for money. I don't regret renouncing the darkroom, but maybe I
shouldn't have got rid of my 4x5 camera....

Peter Marquis-Kyle