Re: [APML] New Planetary Nebula Film Images

["John Boudreau" <jeboud@attbi.com>]

> John, its very interesting to compare the blinking planetary with film and
> CCD.  the orange color of the film shot is unique and interesting.

Hi Chris,

Yes, it's certainly interesting how this film and others record colors from
these objects, but in a way it's an exercise in frustration since these film
miss the OIII emission.

I'm planning on going CCD soon, and will start looking more closely at the
available filter options.

John Boudreau
jeboud@attbi.com
http://home.attbi.com/~jeboud/astro.htm

----- Original Message -----
From: "Chris Schur" <cschur@cybertrails.com>
To: <astro-photo@seds.org>
Sent: Sunday, July 21, 2002 11:19 PM
Subject: RE: [APML] New Planetary Nebula Film Images


> John, its very interesting to compare the blinking planetary with film and
> CCD.  the orange color of the film shot is unique and interesting.
>
> Chris
>
> -----Original Message-----
> From: owner-astro-photo@seds.org [mailto:owner-astro-photo@seds.org]On
> Behalf Of John Boudreau
> Sent: Sunday, July 21, 2002 6:01 PM
> To: astro-photo@seds.org
> Subject: [APML] New Planetary Nebula Film Images
>
>
> Finally, I have some recent images!
>
> I shot M57 for 90 minutes back in June, and recently attempted to get some
> additional frames to combine with the June shot. But operator error has
kept
> me from getting any more M57 shots--- I've fallen asleep only to wake up
to
> sunrise with the shutter still open <G>, and recently an exposure that was
> timed
> as 90 minutes under a very good sky inexplicably looks like a 30 minute
> exposure. Maybe the cable release lock failed, but I don't recall that
> happening
> in the 10 years or so I've had this cable. First time for everything , I
> guess.  ;o(
>
> However my single June M57 exposure processed out very well. It beats my
old
> Provia 100F shot of it taken last year. The new M57 image is at:
> http://home.attbi.com/~jeboud/m57.htm
>
> On the same night I experienced what may have been the cable failure on
M57,
> I
> shot a 20 and then a 30 minute exposure of NGC6826, the "Blinking"
> Planetary. The result of the 2 exposures is at:
> http://home.attbi.com/~jeboud/ngc6826.htm
> Keep in mind that this planetary is less than 30 arcsecs, or approximately
> 1/3 the size of M57.
>
> On many of these planetaries their surface brightness is strong enough to
> record well in such short exposures, but with this NGC6826 film result
there
> are large areas of the planetary that didn't record _at_ all_, but easily
> are
> recorded by CCD. Take a look at:
> http://home.attbi.com/~jeboud/ccd_ngc6826.htm
> This is a CCD image that Sean Walker and myself took last year. What may
be
> described as it's "pinched cheeks" are called "fliers" in planetary nebula
> lingo. See: http://www.astro.washington.edu/balick/W_F_P_C_2/
>
> While the fliers easily show up in both the film and CCD images, the
regions
> outboard of them are easily recorded by the CCD. The film image doesn't
show
> a trace of these regions. I hope to get a long film exposure to see if I
> can record them, but these regions may be essentially all OIII. As good as
> 100F is, it certainly doesn't come close to the recording power of CCD at
> the OIII lines.
>
> Many of you are probably familiar with the greens and blues hues of OIII
in
> CCD images of these and other planetaries, especially since it was
discussed
> a few days ago here on APML. While 100F records *some* of these colors in
> the most heavily OIII laden planetaries, the dominate color in these film
> shots is from their H-alpha and NII emissions.
>
>
> Processing on both of these shots was done with Photoshop and MaxIm DL.
> Since the film's R channel is so fine-grained, a copy of the R channel was
> successfully deconvoluted and unsharp masked and then used as a
luminescence
> channel to make an LRGB of M57. The luminescence channel for the NGC6826
> LRGB image was actually made from both the R and G channels. Don't ask me
> why...  I'm just still experimenting. <g>
>
> Actually this work is done on a close crop of the object, as doing all
this
> on the entire image whould be a nightmare with the large files. At least
on
> my computer. The cropped result is then cloned back onto the unsharp
masked
> and minimum-filtered starfield.
>
> Kinda sounds like I'm cheating, doesn't it?
> :) :) :)
>
>
> John Boudreau
> jeboud@attbi.com
> http://home.attbi.com/~jeboud/astro.htm
>
>
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