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Reprocessed - NGC 891

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#1 srosenfraz

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Posted 07 January 2013 - 10:08 PM

I'm still waiting for my mount to come back home from its vacation in Arizona (at Ed Thomas' for tuning and maintenance), so its left me with some spare time to do more reprocessing. This time I used my DSLR-LLRGB workflow to retackle my NGC 891 image from December 2011:


Posted Image

More image information available at http://www.astronome...php?c=113&p=477. Be sure to look at the High Resolution Version, as there's a nice collection of faint fuzzies scattered throughout the field.

This image is from a stack of 190 x 180 seconds (9 1/2 hours total exposure) at ISO 1600 captured with a Gary Honis modified (Baader) Canon 450D. OTA was an orange tube Celestron C-8 using a Celestron focal reducer at f/6.3 (1260mm). Guiding was with an 80mm f/11 refractor, SSAG autoguider, and PHd Guiding.

For those who are curious, here is a link to the prior version.

Thanks for looking!

#2 fco_star

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Posted 07 January 2013 - 10:19 PM

Scott, so many details in your picture, is beautiful!

#3 shrevestan

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Posted 07 January 2013 - 10:20 PM

Another winner! Great "3D" feel to it.

#4 David Pavlich

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Posted 07 January 2013 - 11:02 PM

I really like it! One of my favorite objects.

David

#5 Nils_Lars

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Posted 08 January 2013 - 12:23 AM

Some sharp details in this Scott.

#6 mmalik

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Posted 08 January 2013 - 06:15 AM

Much better than the previous rendering Scott. Just some thoughts on the star color (NOT about NGC 891 per se); may be soon I'll start processing my images like yours and others but up till now my take is that that saturated star color (predominantly blue, mixed with red/browns [Note: Naturally red/blue shifted star/galaxy colors is NOT what I am referring to here]) gives a hint of over-processing and/or synthetic feel to the images in my opinion. I know you have explained the bluish theme in the other thread already; my comments are not a critique, just something to ponder over and what I feel is quite prevalent in most of yours and other experienced processors' images. May be it is a good thing; I have yet to learn to see it that way :). Regards

#7 jambroseus

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Posted 08 January 2013 - 01:32 PM

Looks great Scott!

John

#8 Mike Clemens

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Posted 08 January 2013 - 01:40 PM

You are getting great results.

#9 AstroScience

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Posted 08 January 2013 - 01:43 PM

Almost missed that one. The galaxy looks beautiful, Scott, tiny details of dusty edge is amazing!

#10 srosenfraz

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Posted 08 January 2013 - 04:54 PM

Thank you everyone for such nice feedback.

@Mike (Malik) - Thank you for your input and honest critique - Its always helpful to know those aspects of my images where others feel I could improve. You've been cranking out some very high quality images recently, so I wouldn't want to miss such valuable feedback.

#11 WarrenS

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Posted 08 January 2013 - 06:44 PM

Very nice Scott, probably one of the nicest DSLR NGC891's I've seen here.

#12 WhitenerJ

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Posted 08 January 2013 - 09:17 PM

Great shot!!! Nice detail in the galaxy!!

Jason

#13 petemumbower

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Posted 09 January 2013 - 12:46 PM

Amazing what a different round of processing can do with the same set of data. One thing I noticed looking at the high-res is how the stars seem to have blue halo at the 10 o'clock position and a red halo at the 4 o'clock position. Is this just an artifact from the scope optics or reducer?

#14 srosenfraz

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Posted 09 January 2013 - 09:29 PM

Thank you for your kind comments Warren, Jason and Pete. @Pete - there's some chromatic aberration introduced from the focal reducer. I actually used the Lens Correction filter in Photoshop on this image that minimized the CA (it removed most of the CA that radiates away from the center). But, there's some residual channel misalignment. I probably should have cleaned it up a hair more (or not post such high res versions!) - thanks for pointing that out.






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