About the Blog

This blog contains recent projects, activities, and musings about astrophotography and space, to view my main webpage with prints for sale, final images, and Annie's Astro Actions, please visit: www.eprisephoto.com


Monday, April 19, 2010

NGC 3718 ... the comparison of dark versus urban skies

My latest project was to test the limits of imaging a) in the city and b) without an autoguider on my wedge-mounted scope. I chose NGC 3718 as I dont see many pictures of it and I think it looks cool and it has not only the main galaxy but alot of faint wispies that I figured (rightly) that I wouldnt be able to pick up in the city. I planned this so I had a week or two here in San Antonio to work on it and get data before my vacation to Big Bend where I would be able to get DARK DARK skies to get data for it there.

I found out that I can get 10 minute subs with no autoguider with my piggybacked EON (piggybacked on a CPC800) with slight tweaking over a week, though I kept most of my subs to 250sec as I still need to do a decent PEC training.

I also determined that no matter how many hours you get in the city it cant compare to a few hours in the ink black skies of Big Bend! Here is the comparison .... 

the first is 7 hours worth of Luminance data taken from San Antonio, mostly all 250sec subs, with a few 500sec subs in there. 

The second is the original 7 hours of data and then 2.5 more hours from Big Bend added to it. 

My the difference a few hours with absolutely no light pollution can make!!!! SO many more stars and now I was able to pull out the faint wispies I wanted to!

Now, just to get color to add to it next month when I head out to West Texas again for a star party to get more imaging time in dark skies ....

Here is the info for the shots:
Scope: Orion EON 80ED piggybacked on a CPC800
Camera: Atik 314L+
Autoguider: NONE
Filter: Astronomik Luminance
Exposure time: Image 1: 7 hrs, Image 2: 9.5 hrs
Sub length: 250 sec, (a few thrown in at 500 sec) 

Really makes the case for getting rid of light pollution and bringing back our dark skies!!!!

Monitor Calibration

Monitor Calibration
The grayscale above presents 24 shades of gray from pure white to solid black. If you cannot see all 24, your monitor needs calibration to view the astrophotos correctly: I recommend the site linked in the image