Pentax k1x0D long exposures (astro photography)

It is yet quite hard to find at least several expert reviews on one of
the 2 new Pentax DSLRs, so behavior at high ISO and long exposure i.e.
5-10-15+ minutes is to me so far unknown.
Is it better or worse than the Nikon's D50/D70 or one of the *ist
series camera?
Is it "improvable" by any means?
(I am not discussing the Canon CMOS DSLR's on this issue, everyone
interested knows they are the best for this kind of work)
The Nikon's workaround for not having the dark frame extracted is, tho'
efficient, quite barbaric IMHO.
If I know well, the D80 has the possibility to disable this dark frame
extraction feature. Also, from what I've read in the K100D's manual,
there is also possible to disable Noise Reduction. If I know wrong,
please correct me. How much improvement does that bring, if any?
The low price on these cameras, together with the overall kit lens
optics, construction and handling quality makes my wish gland drool.

"mirceaar" wrote in message
ups.com...
It is yet quite hard to find at least several expert reviews on one of
the 2 new Pentax DSLRs, so behavior at high ISO and long exposure i.e.
5-10-15+ minutes is to me so far unknown.
Is it better or worse than the Nikon's D50/D70 or one of the *ist
series camera?
Is it "improvable" by any means?
(I am not discussing the Canon CMOS DSLR's on this issue, everyone
interested knows they are the best for this kind of work)
The Nikon's workaround for not having the dark frame extracted is, tho'
efficient, quite barbaric IMHO.
If I know well, the D80 has the possibility to disable this dark frame
extraction feature. Also, from what I've read in the K100D's manual,
there is also possible to disable Noise Reduction. If I know wrong,
please correct me. How much improvement does that bring, if any?
The low price on these cameras, together with the overall kit lens
optics, construction and handling quality makes my wish gland drool.


I have only done a few ten minute exposures but on my DS (and it should be
similar) the DFS works quite well. I did some testing in a dark room and had
some flare particularly at the edges that was dealt with apparently quite
nicely by the DFS. Probably fairly similar to the Nikons with DFS.

mirceaar wrote:
It is yet quite hard to find at least several expert reviews on one of
the 2 new Pentax DSLRs, so behavior at high ISO and long exposure i.e.
5-10-15+ minutes is to me so far unknown.

High ISO is useless in any DSLR for astrowork. As for reports
unfortunately I know of no one.

Is it better or worse than the Nikon's D50/D70 or one of the *ist
series camera?

I bet they're better than the *ist (far too noisy) and probably with
more noise than the D50.

Is it "improvable" by any means?
(I am not discussing the Canon CMOS DSLR's on this issue, everyone
interested knows they are the best for this kind of work)

They're not, except maybe the Da.

The Nikon's workaround for not having the dark frame extracted is, tho'
efficient, quite barbaric IMHO.

Is not about the dark frame but rather about median filtering. Besides,
it can be automated.

If I know well, the D80 has the possibility to disable this dark frame
extraction feature. Also, from what I've read in the K100D's manual,
there is also possible to disable Noise Reduction. If I know wrong,
please correct me. How much improvement does that bring, if any?

Difficult to say without knowing exactly what it is supposed to do and
what effectively does, isn't it?

The low price on these cameras, together with the overall kit lens
optics, construction and handling quality makes my wish gland drool.

If you're happy with QE at best 2x of high end film than yeah,
otherwise yawn..

Andrea T.

Note followup.

" wrote in
oups.com:

Of noise and such in digital cameras for astrophotography:

mirceaar wrote:
(I am not discussing the Canon CMOS DSLR's on this issue, everyone
interested knows they are the best for this kind of work)

They're not, except maybe the Da.

Would you care to elaborate on that? I expect to make that decision in
the medium term. I have a certain amount of Nikon glass and no Canon
anything. If a Nikon D-80 lets me get reasonably close to a Digital
Rebel XT I will be a happy camper.

The Nikon's workaround for not having the dark frame extracted is,
tho' efficient, quite barbaric IMHO.

Is not about the dark frame but rather about median filtering.
Besides, it can be automated.

How is it automated? A pointer to some information would be fine.

If I know well, the D80 has the possibility to disable this dark
frame extraction feature.

Question for mirceaar:
May I ask where you got that information? It would be of considerable
interest to me to be able to follow-up on it.

- Shankar