Digital BW, The Print

> From: Truman Prevatt [mailto:tprevatt@...]
>
> No matter what your eye tells you, information cannot be created.  Given
> a fairly complex image, the interpolation looks okay, but take it to the
> bench for testing and it will show at that point. Give it a particularly
> difficult image and it will have some artifacts (it is a not only a
> smoothing operation it is non-linear and non-linear operations will
> product artifacts).

But the eye is all that matters. Your statement makes me wonder whether
you're using your camera for art or for lab measurements.

I know what constitutes a "difficult" image, because my old Minolta D7
didn't have such a good interpolator. It would show color noise on fine
lines, like individual hairs. The 10D's internal interpolator, and the one
in the latest Adobe Camera Raw, are much better than that. They can indeed
render detail down to the pixel level, so they're not simply smoothing, but
I have yet to see anything out of them that the eye would recognize as a
wrong pixel. Now, if you took a picture of some sand, roughly matching the
grain size to the pixel size, I'm sure it wouldn't render the color of each
grain as precisely as the Foveon chip, but who cares, as long as it looks
like sand? Where it matters is where the eye would see the difference.

> As far as resolution comparision check
> http://www.dpreview.com/reviews/sigmasd9/page23.asp where the reviewer
> pegs the SD9 better than the six meg sensors out there.  Its resolution
> is better according to the table in the above review to the 6's out
> there. I've seen ads for the SD9 that claims an "effective" 10 meg
> resolution. One was in the last B&H catalog I received.

Yes, that's BECAUSE there's no anti-alias filter over it.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...