On Mon, 04 Jul 2005 20:27:37 GMT, Gregory
wrote:

These one-shot colour DSLRs are pretty popular, and
are obviously taking a *lot* of business away from
dedicated astro camera manufacturers such as SBIG
and Starlight-Xpress.

I doubt they are having much impact on these companies. Maybe on their
one-shot color cameras, but those are just for newbies anyway, and don't
represent a large part of their business (not for SBIG, anyway). In
fact, I wouldn't be surprised if DSLRs are helping astrocamera
manufacturers, since they represent a cheap way into the hobby, but
don't provide much room for growth (so some users graduate to more
serious cameras).


Why should a newbie such as myself pay $6000 for a
dedicated 6-MegaPixel astro CCD, or $1300 for a
low-end 0.4-MegaPixel astro CCD, when $1400 can buy a
less sensitive, less specific, but perfectly adequate
large-format dual-purpose CMOS camera such as Hutech-
converted Digital Rebel?

It depends what you are after. One of the biggest mistakes beginning
imagers make is thinking they need lots of pixels. The actual number of
pixels you need is determined by how large a field you want to image. If
you are interested in imaging typical DSOs through a moderate focal
length instrument (like an SCT) there is little need for megapixels.
Also, you shouldn't underrate the value of cooling. A dedicated
astrocamera has _much_ better noise characteristics than even the lowest
noise DSLRs (Canons), and more than anything else it is noise that
determines image quality. Finally, color sensors do not generally
produce good results compared with individual B&W exposures made through
color filters. In short, if "adequate" is what you are shooting for, a
DSLR may serve you well. If your goal is to keep pushing your skills and
produce high quality astroimages, however, you will rapidly outgrow the
DSLR.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com