Digital BW, The Print

> From: scrber [mailto:stephen.bate@...]
>
> After 2-3 years of digital darkrooming and B&W printing I am still
> not happy with my methods to darken blue skies.
> I am familiar with the red filter / polariser filters on film
> capture, but my efforts to successfully replicate this digitally
> have never been particularly fruitful.  I have tried many channel
> mixer, hue/sat methods to convert my digital colour images to B&W
> but all result in some sort of posterisation or noise in the sky.  I
> cannot get a smooth dark sky.  Selective darkening also is very
> difficult if you are really trying to go dark, the halos/  edges are
> almost impossible to avoid.
> Even after running neat image or selective bluring to remove sky
> noise I end up with clear banding in the sky as it gets darker.

It's true that extreme color shifts prior to grayscale conversion can
amplify noise or introduce posterization. The two are to some extent
mutually exclusive, in that noise breaks up posterization--which is why
NeatImage on an 8-bit image can turn noise into posterization. This is a
good reason to use the new PS CS, which supports 16-bit mode for most
operations.

When I shoot with my 10D at ISO100, the noise level seems quite low after
using the Channel Mixer to get a really dark sky. Is it possible that your
original source is just too noisy? Or maybe you have a lower tolerance for
noise than I do.

I put a 1:1 crop from a B&W image in http://www.pbase.com/image/24112078.
This isn't a "finished" picture, in that all I did with it was use Channel
Mixer and Levels, so it has plenty of flaws. But is this sky too noisy for
you? Not dark enough?

--

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