Re: [APML] New Tricolor

["Robert Gendler" <robgendler@worldnet.att.net>]

Hi Chuck,
Great to see a new image from you.
One question I have is that the bluish tones seem dominate the
top 2/3 of the image and are fairly absent from the bottom 1/3.
Is this the nature of the nebula or is there a blue gradient?
Rob Gendler
Email: robgendler@att.net
Web site: http://www.robgendlerastropics.com/
----- Original Message ----- 
From: "Chuck Vaughn" <aa6g@aa6g.org>
To: <astro-photo@seds.org>
Sent: Wednesday, August 27, 2003 6:15 PM
Subject: [APML] New Tricolor


> List,
> 
> It's been almost 2 years since I was able to take an astrophoto but I 
> now have a temporary setup at my new place and can take photos again. 
> What a joy it is to be able to walk out your back door, start a photo, 
> climb into your own bed for a nap while it is autoguiding away.
> 
> I haven't had time to update my web page so it's just a jpeg download. 
> This is the IC5068 region south of the Pelican. This is not my most 
> spectacular tricolor but it's more of an experiment with a new scope.
> 
> http://www.aa6g.org/Astronomy/Astrophotos/ic5068.jpg   (186KB)
> 
> Here are the details:
> 
> AstroPhysics 155EDF
> Kodak TP2415 hypered
> Custom RGB Filters
> Exposure Times: R:G:B  90:180:180
> 
> These are the first exposures I've taken with the 155EDF since I bought 
> it used 2 years ago. I had done all the work to ready it for 
> photography but never had an opportunity to use it. I didn't know what 
> was going to happen. I'm very pleased with the image quality. The stars 
> are very tiny.
> 
> I decided to run the correct relative exposures unlike what I was doing 
> with the old 130EDT, which was to run three 180 minute exposures and 
> compensate in Photoshop by adjusting the green and blue exposures. 
> Compared to previous tricolors, the red exposure is about 1/3 shorter 
> and the green and blue are about 1/3 longer. When photographing 
> nebulas, I'm considering taking two 90 minute red exposures and 
> averaging them to reduce the overall grain somewhat. This could work 
> out fine, a 90 min red and a 180 min green on one night and a 90 min 
> red and a 180 min blue on another.
> 
> A surprise was that there is no vignetting in the corners of the 35mm 
> frame with this setup. I believed that to be impossible with a 35mm 
> camera body. The only thing that is new is a much larger corrector 
> lens. The OAG and the OM-1 are the same.
> 
> FYI: I didn't have time to hyper new film so these exposures were taken 
> on film hypered on Oct. 5, 2001 and stored in the freezer since then. 
> TP lasts a long time!
> 
> Notes on my new location... I'm 2 miles east of Mountain Ranch at 2500 
> feet almost at the top of a hill. The only easily visible light 
> pollution is coming from Sonora, which was a surprise, but my horizon 
> is about 1 degree in that direction. My west is blocked by a hill up to 
> about 10 degrees and I don't see much coming from the Central Valley. 
> So far, under stable weather, the morning low is only 2-3 degrees F 
> below the temperature at the end of twilight. The scope holds focus 
> very well. Nights are calm to very light breezes, almost more of an air 
> flow than real wind. There's quite a few planes on various routes so 
> I'm bound to catch one sooner or later.
> 
> Finally, I saw my first aurora on Aug. 24 at 0700 UTC. It went up to be 
> about 30 degrees in the northeast, moved around and then disappeared in 
> about 10 minutes. There was no color. It looked like light pollution. 
> :-)
> 
> Chuck <aa6g@aa6g.org>
> 
> _______________________________________________
> Astro-Photo mailing list
> Astro-Photo@seds.org
> http://seds.org/mailman/listinfo/astro-photo

_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo