Digital BW, The Print

> A long time ago I called Kodak's digital division and asked a few
> questions, one of them being, how many pixels would it take to equal the
> information on a Kodachrome ISO 25 film. He said 12 million pixels would
> equal Kodachrome. Don't know if this is still true, but he seemed to
> know what he was talking about. That was years ago when a 12 million
> pixel chip was only a dream.
> Jer

Hi Jerry,

That claim doesn't match their Kodachrome 25 data sheet, and there are many
issues that are really misleading WRT that claim.  Do you know the persons
name?

Your camera uses a Bayer pattern "imaging device", which does NOT give you N
mega-pixels (what ever the spec says).  It gives you %50 green, %25 red and
%25 blue.  The camera software interpolates that information into giving you
N mega-pixels out of the camera, but the sensor is NOT an N mega-pixel
sensor.  Color film does not have this issue, it has color information for
every "spot" on the film.

The resolution of Kodachrome 25 (which, BTW, is not near as good as modern
films), according to Kodak supplied data, at a contrast ratio of 1.6:1 is 63
lp/mm, and at 1000:1 is 100.  So, let's say it's 75, since the real number
that represents practical reality is somewhere between that.  That gives an
equivalent resolution of 150 x 24 x 150 x 36 or 19,440,000 TRUE pixels.
Better films are substantially more than that.

Regards,

Austin