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I'd go with the IDAS filter, as Ulrich suggests.
Sean Walker
Michael Gartland wrote:
Sean...thanks for the response!
Coincedentally funny...my procedures book was already open to Matt's
vig procedure as I was reading your response....I was working it on some
older scans...trying to get more proficient...your procedure did work on
some other scans I was doing, but it doesn't seem to work as well when
there is a lot of variation in the field....I am still learning...my B33
processing is cooking my brain...trying to process the most out of my negs...when
I maximize the most from the Hosehead region, I red out the flame, when
I get the flame contrast right, I lose all the detail in the Horsehead...trying
to achieve the best tradeoff...recipe ain't there yet.. getting inovative....I
just had to order a 40Gig HD to run Win2K just for running Photoshop and
take advantage of my RAM.
Do you still think a good general LP filter is worth it, like the Lumicon
Deep sky Photographic?
Sean Walker wrote:
I think you interpeted my comments exactly. the same
techniques for reducing vignetting can be used to subtract sky glow also.
The drawback here though is that the more LP there is in an image, the
less wanted signal is leftover after processing, and thus a noisier image
results. In my article in the September issue of S&T, the opening image
of B33 was taken in the worst part of the sky- mag 5. as you can see, the
raw scan looks pretty pathetic. Advanced Photoshop users are strongly encouraged
to learn Matt BenDaniels method, as it offers greater control over the
image.
Sean Walker
Michael Gartland wrote:
Sean...can you please explain your view on the "sky
fog myth"? I am losing more and more sky every year due to LP encroachment
and have cut back on my exposure times accordingly...as a result I feel
like I am am clawing for every little bit of signal in processing....are
you saying I should go back to (60min or longer) exposures, take all the
signal and (fog) I can get without (whiting out) the exposure and then
processing out the (unwanted) noise? Am I interprting your comments accordingly,
or am I making too big of a leap?
As an aside, I have avoided using an LP filter, only one I have is a
(1.25") broadband I have used visually. I have tried to avoid the expense
for a (series) of 2" LP filters, am I just delaying the ineveitable? If
so any suggestions on a general use broadband spectrum LP filter I should
start off with?
Thanks for any comments!
m.g.
Sean Walker wrote:
No problem-
Nice new shots, BTW.
I'd refer to the old processing challenge last year for getting the
most out of that Rosette shot, myself. Also I think you should be doing
longer exposures before stacking- ignore that sky fog myth,so the grain
will be even less apparent. just my 2 cents.
Sean Walker
Chris & Jennifer Cook wrote:
I
wasn't aware of using the 400F for deep sky work. Thanks Sean for
pointing John's images out. I was aware he had been using 100F on
planetary nebs. Chris==================
Chris Cook
Astronomical Photography
www.abmedia.com/astro
-----Original
Message-----
From: Tony Hallas <tonyhallas@foothill.net>
To: astro-photo@seds.org
<astro-photo@seds.org>
Date: Saturday, December 08,
2001 12:58 PM
Subject: Re: [APML] Provia
trails
Chris,
Isn't it Provia 400 F that is all the rage right now in Japan for deep
sky work? Has anyone tried this out for deep sky with a telescope?
Tony
--
Have a Nice Day!
m
Email: mgartlan@iconn.net
--
Have a Nice Day!
m
Email: mgartlan@iconn.net
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