OT - Photoshop question

I use Photoshop CS2 (and sometimes the Gimp) to edit my astro pics.
In both cases one have the possibility to edit the RAW file (Nikon-NEF in my
case) before importing them into PS as a psd files.

I have learned the basic tricks to improve the pictures in PS, but I have
never seen anyone mention this 'preprocessing' stage. (temperature,
exposure, shadows, detail, curves etc..)

Any thoughts and general guide lines on how to handle this?
Purpose of course to get best possible result.
I have googled without luck, so pointers would be appreciated.

And since I'm off topic already, 'Photoshop for Astrophotographers' and 'A
Guide to Astrophotography with DSLR Cameras', both by Jerry Lodriguss.
Any thoughts on these?

Thanks

Iordani wrote:
I use Photoshop CS2 (and sometimes the Gimp) to edit my astro pics.
In both cases one have the possibility to edit the RAW file (Nikon-NEF in my
case) before importing them into PS as a psd files.

I have learned the basic tricks to improve the pictures in PS, but I have
never seen anyone mention this 'preprocessing' stage. (temperature,
exposure, shadows, detail, curves etc..)

Any thoughts and general guide lines on how to handle this?
Purpose of course to get best possible result.
I have googled without luck, so pointers would be appreciated.

Try Iris http://www.astrosurf.com/buil/us/iris/iris.htm for
per-processing (dark subtraction, flat fielding and general cosmetic
work).


And since I'm off topic already, 'Photoshop for Astrophotographers' and 'A
Guide to Astrophotography with DSLR Cameras', both by Jerry Lodriguss.
Any thoughts on these?

The first one is a valuable resource. I can't say much about the second
one as I haven't got it. From the excerpts I've read I can do without.

Andrea T.

On 18 Sep 2006 12:46:58 -0700, wrote:

And since I'm off topic already, 'Photoshop for Astrophotographers' and 'A
Guide to Astrophotography with DSLR Cameras', both by Jerry Lodriguss.
Any thoughts on these?

The first one is a valuable resource. I can't say much about the second
one as I haven't got it. From the excerpts I've read I can do without.

The second one is actually very good indeed, packed with lots of
information, examples, tutorials and links to other sites.
--
Pete
http://www.digitalsky.org.uk

Iordani wrote:

I have learned the basic tricks to improve the pictures in PS, but I have
never seen anyone mention this 'preprocessing' stage. (temperature,
exposure, shadows, detail, curves etc..)

Although not strictly for astrophotographers, I've learned a lot from
Bruce Fraser's book "Real World Camera Raw with Adobe Photoshop CS2".

Dave Adcock.

Pete Lawrence wrote:
On 18 Sep 2006 12:46:58 -0700, wrote:

And since I'm off topic already, 'Photoshop for Astrophotographers' and 'A
Guide to Astrophotography with DSLR Cameras', both by Jerry Lodriguss.
Any thoughts on these?

The first one is a valuable resource. I can't say much about the second
one as I haven't got it. From the excerpts I've read I can do without.

The second one is actually very good indeed, packed with lots of
information, examples, tutorials and links to other sites.
--

A lot of the stuff on the second one (basically most of the processing
tips) are very similar in the first one so there is some overlap. There
are quite few points which I found where either wrong or misleading.

Andrea T.

On 19 Sep 2006 05:47:17 -0700, wrote:


Pete Lawrence wrote:
On 18 Sep 2006 12:46:58 -0700, wrote:

And since I'm off topic already, 'Photoshop for Astrophotographers' and 'A
Guide to Astrophotography with DSLR Cameras', both by Jerry Lodriguss.
Any thoughts on these?

The first one is a valuable resource. I can't say much about the second
one as I haven't got it. From the excerpts I've read I can do without.

The second one is actually very good indeed, packed with lots of
information, examples, tutorials and links to other sites.
--

A lot of the stuff on the second one (basically most of the processing
tips) are very similar in the first one so there is some overlap. There
are quite few points which I found where either wrong or misleading.

Such as?
--
Pete
http://www.digitalsky.org.uk

wrote:


Pete Lawrence wrote:
On 18 Sep 2006 12:46:58 -0700, wrote:

And since I'm off topic already, 'Photoshop for Astrophotographers'
and 'A
Guide to Astrophotography with DSLR Cameras', both by Jerry
Lodriguss. Any thoughts on these?

The first one is a valuable resource. I can't say much about the second
one as I haven't got it. From the excerpts I've read I can do without.

The second one is actually very good indeed, packed with lots of
information, examples, tutorials and links to other sites.
--

A lot of the stuff on the second one (basically most of the processing
tips) are very similar in the first one so there is some overlap. There
are quite few points which I found where either wrong or misleading.

Thanks all for your opinions. I did order both and the one suggested by
Dave too.

Pete Lawrence wrote:
On 19 Sep 2006 05:47:17 -0700, wrote:


Pete Lawrence wrote:
On 18 Sep 2006 12:46:58 -0700, wrote:

And since I'm off topic already, 'Photoshop for Astrophotographers' and 'A
Guide to Astrophotography with DSLR Cameras', both by Jerry Lodriguss.
Any thoughts on these?

The first one is a valuable resource. I can't say much about the second
one as I haven't got it. From the excerpts I've read I can do without.

The second one is actually very good indeed, packed with lots of
information, examples, tutorials and links to other sites.
--

A lot of the stuff on the second one (basically most of the processing
tips) are very similar in the first one so there is some overlap. There
are quite few points which I found where either wrong or misleading.

Such as?

Such as writing that CMOS as seen in DSLR have QE up to 50% when in all
likelyhood we are talking 8-10% here. Or such as recommending 800 or
1600 ISO for deep-sky work. Or as saying that you need the mirror
lock-up if you want to shoot the planets/moon/sun. From what I've read
it seems to be heavily centered on Canons and the Da in particular.

Andrea T.

On 19 Sep 2006 13:59:10 -0700, wrote:


Pete Lawrence wrote:
On 19 Sep 2006 05:47:17 -0700, wrote:


Pete Lawrence wrote:
On 18 Sep 2006 12:46:58 -0700, wrote:

And since I'm off topic already, 'Photoshop for Astrophotographers' and 'A
Guide to Astrophotography with DSLR Cameras', both by Jerry Lodriguss.
Any thoughts on these?

The first one is a valuable resource. I can't say much about the second
one as I haven't got it. From the excerpts I've read I can do without.

The second one is actually very good indeed, packed with lots of
information, examples, tutorials and links to other sites.
--

A lot of the stuff on the second one (basically most of the processing
tips) are very similar in the first one so there is some overlap. There
are quite few points which I found where either wrong or misleading.

Such as?

Such as writing that CMOS as seen in DSLR have QE up to 50% when in all
likelyhood we are talking 8-10% here. Or such as recommending 800 or
1600 ISO for deep-sky work. Or as saying that you need the mirror
lock-up if you want to shoot the planets/moon/sun. From what I've read
it seems to be heavily centered on Canons and the Da in particular.

To be fair to Jerry, the reference to QE was based on the empirical
findings of Roger Clark and others which show a paeak QE in the green
part of the spectrum at around 50%.

800-1600 ISO is used because most DLSR imagers don't autoguide. Again,
to be fair to Jerry, he does explain that lower ISO values will give
better results if you can use them.

The Canons are the best DLSRs for atrophotography for numerous
reasons. The 20Da is the best non-modified model in the range for the
purpose so it's not surprising that these would be heavily mentioned.
To be honest, books that claim to be generalised treatments of a
subject which then blinker themselves to delivering material on just a
narrow range of equipment drive me nuts. Although a lot of the
examples shown in this particluar book are Canon based, I felt that
the effort was being made to expand the treatment to other makes and
models as well.
--
Pete
http://www.digitalsky.org.uk

In message , Pete Lawrence
writes
On 19 Sep 2006 13:59:10 -0700, wrote:

Such as writing that CMOS as seen in DSLR have QE up to 50% when in all
likelyhood we are talking 8-10% here. Or such as recommending 800 or
1600 ISO for deep-sky work. Or as saying that you need the mirror
lock-up if you want to shoot the planets/moon/sun. From what I've read
it seems to be heavily centered on Canons and the Da in particular.

To be fair to Jerry, the reference to QE was based on the empirical
findings of Roger Clark and others which show a paeak QE in the green
part of the spectrum at around 50%.

800-1600 ISO is used because most DLSR imagers don't autoguide. Again,
to be fair to Jerry, he does explain that lower ISO values will give
better results if you can use them.

The Canons are the best DLSRs for atrophotography for numerous
reasons. The 20Da is the best non-modified model in the range for the
purpose so it's not surprising that these would be heavily mentioned.

Um, shouldn't that be _modified_?
According to http://www.bobatkins.com/photography/digital/eos20da.html
it's apparently done specifically for astrophotography, with the
blocking filter modified and mirror lock-up added.
And according to
http://telescopes.com/products/canon-canon-eos-20da-digital-slr-38611.html
it costs $2495 - read pounds, at least - has a live preview and _has
been discontinued_ :-(