Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Seth"
<seth@m...> wrote:
>  Keep in mind that lenses don't focus all colors on the same plane.

Isn't that exactly what the term "chromatic abberations" (as used in
my post) means?

  It was
> great for color film since the film also has separate layers.
> 
> True the digital glass is tweaked for digital, but a point and shoot
doesn't
> get all the technology and quality of high-end glass.   It's all about
> price, features and megapixels.
> 
> "Yuz pays ur money and yuz takes ur chances"
> 

So what's your point--except the obvious? My point was simply to try
to answer the previous question by describing my experience--that
chromatic abberations can appear much more severe in a converted B&W
than in the original color image; and that judicious use of the
blue-channel info can minimize the problem in B&W. Naturally by using
better optics that avoid chromatic abberations you can, well, avoid
chromatic abberations/purple fringing.

Phil.

> 
> ==-----Original Message-----
> ==From: Phil Rose [mailto:pjrose@f...] 
> ==
> ==Funny you should ask. I recently worked on a RAW image of a winter
> ==(snow) scene taken with my 5 mp Canon S50. After converting 
> ==from RAW and then doing a B&W conversion, I began to notice 
> ==some strange
> ==lines-- "ghosts"-- in the image: these pale lines ran 
> ==alongside (parallel to) various high-contrast edges 
> ==throughout the image (wherever there was snow against dark 
> ==background. 
> ==