Hey Moon, You want a piece of me!?! C'mon!!!

While using the moon-polluted part of the month to refine some of the technical pieces of this hobby (sickness, addiction, obsession - choose one) I chose to shoot NGC 4565 as the subject for some other testing I was doing. Details on that testing to come later. I took a total of 60 minutes of exposure while the moon was living large just 30º away on Friday night. Except for the gradient of the moonlight, I was really happy with the way that the subs themselves came out. Being that I'm still trying to justify my cost-per-hour in this hobby I thought it might ease the guilt if I processed that set of data too.

I shot 20 exposures at 3 minutes each through the CGEM 1100HD and Hyperstar with my QHY8PRO camera. Data was captured and autoguided with Maxim DL and had the benefit of a Hutech LPS-P2 light pollution filter helping out as well. The original stack of the data looks like this before any post-processing:
NGC4565 Gradient by Mike Wiles, on Flickr

I've been experimenting with doing more of the heavy-lifting type processing in Maxim DL prior to moving over to Photoshop to finish the image.

In Maxim DL:

• A slight crop of the image to remove the ragged edges from dithering.
• Auto Remove Gradient
• Auto Flatten Background
• Color Balance
• Remove Background Color
• Log Stretch
• Gamma Stretch
• Save as .tiff and get on with Photoshop

In Photoshop CS5 I did the usual Curves, Levels, Saturation work and saved to a .jpeg Here is the outcome of that processing in the 2.5 degree by 1.5 degree field of the Hyperstar.
NGC4565 Wide Field by Mike Wiles, on Flickr

And finally, a 100% crop of the central area.
NGC4565 Closeup by Mike Wiles, on Flickr

You can see that the image at full resolution is pretty darn noisy from the less than awesome shooting conditions and processing, but it was still a fun shot to process. Using the wide field shot to mask some of that noise gives me an image I'm pretty happy with. Like my recent M57 shot, I don't think this is something I would go out of my way to shoot with the wide field of the Hyperstar, but it's an interesting shot now that I look at it.

I actually took the shots to take some measurements on whether or not using Periodic Error Correction has a positive influence on autoguided images. I haven't studied the data enough yet to offer my own conclusion. I'll cover that in a future post. Please feel free to throw rocks at my images and tell me about it.

Can you tell that I really need to get to a dark sky with some decent weather conditions? I don't know how some of you do it living in places where you go months without being able to image. My hat is off to you for your patience.

Imaging M57 with Hyperstar

Yep. Not a misprint my friends. You did just see "M57" and "Hyperstar" in the same sentence. No, I haven't been drinking. Work, weather and other factors have conspired to prevent me from getting some good imaging time from really dark skies....so I've resorted to my own light polluted back yard. This one simply started out as a session to work on Hyperstar collimation and dialing in the autoguiding a little better in an effort to get stars that are more sphere shaped. When I finished, I put the Hutech LPS-P2 filter into the Hyperstar and pointed the scope at M57 which was at about 45º above the horizon at the time directly in the Phoenix Nebula...errr light dome of Phoenix, Arizona. This is a composite of 100 minutes total exposure. I am really pleased so far with the Hutech filter. There was a pretty big gradient in the image but it was simple to process out and I didn't have to fight any weird color bias in the process.

There still seems to be some collimation issues, but overall I'm feeling better about the image than some of my previous stuff. What bothers me still is that the upper right corner of the frame seems to be much worse than anywhere else in the image for less than round stars.

Date: 05/14/2011
Location: Goodyear, Arizona
Telescope & Mount: Hyperstar 3 equipped Celestron CGEM 1100HD
Camera - QHY8PRO
Real Focal Length - 545.3mm f/1.95
Image Scale - 2.95"/pixel
Exposure - 100 x 60 seconds
Calibration: Bias, Flats & Bad Pixel Map - No dark frame subtraction
Software: Maxim DL 5 & Photoshop CS5

While this isn't the type of shot that I'm looking to get on a regular basis, I do find some appeal in the way that the tiny nebula sits in the dense star field. This frame is about 2.5º by 1.5º. The second image is a 100% crop of just the center of the image.


M57 courtesy of the CGEM 1100HD and Hyperstar (click to see full size)





Crop of the center portion of the image.  Galaxy IC1296 is visible to the right of the nebula.