Posts Made By: Sam Pitts

I know how it is to be away from imaging. Here in Oregon I can go 6-9 months without good weather to image.

Great wide field shot of M27 showing lots of faint detail around M27. Lots of exposure time really has its benefits.

Sam

Nice image, C8 with reducer did well. Nice colors and details, just think what it would have taken to get such fine results with film. Some good imaging can be had with such equipment without breaking the Bank.

Sam

I used to use two 6v golf cart batteries to give 12v approx. 225+ amp hr. I now use a Honda 2000u generator (clean sign-wave), 1/3 the weight and runs all night on a tank of gas(1.1 gallon). I can run 2 AP1200, 2 CCD, 2 laptops, dew-heaters and more with no problems. I can even fire-up a microwave for a midnight snack. I find it better then lifting and moving 2-80 lb batteries and worrying about acid spells and running out of power.

sam

I assume you are using the Canon EF-S 10-22mm f/3.5-4.5 USM. I see distortion on the left side as well and this is common with wide angle lens. Zoom lenses are not as good as fixed for astronomy, but do produce good results. I usually have to stop down 1-3 stops with wide-angle lens to resolve the problem. The wider the angle the more you have to stop down. Using a 50mm f/1.2 I stop it down to f/2.8. 35mm f/2.0 to f/4, and 20mm f/2.8 to f4-5.6. 20d with 20-35mm f/2.8 needs to be stopped down to 5.6 (2 stops). You may have to stop the 10-22mm down even further since it has a variable f-ratio. There will also be distortion in stacking since every image will have different refractive values near the edges compare to the center of the image from the atmosphere. The stars near the horizon will be different from frame to frame between exposures. This distortion can be corrected in Photoshop to some degree. (See R. Scott Ireland’s Book)

Normally the distortion is not noticeable in normal photography, but we push the limits shooting stars (pin points). I have seen this distortion to a much lesser degree using a Cannon 300mm f/2.8 (one of the best lenses made) imaging stars.

Distortion closer to the horizon really surfaces when you try to do mosaics.

Sam

Samsastro.com

Nice shot great detail with 40d,wish they made the Tec200 still. How many subframes and duration?
Thanks for sharing a great image

Sam
www.samsastro.com

Nice shot, good detail. Wish I could get out (Rainy NW %^#!!)

Thanks for sharing

Sam

I would be interested, it is nice to be able to overlay on an image and locate and ID stars and faint galaxies.

sam

samsastro.com

Nice, even a hint of Barnards Loop. You might want to try making copies and adjuting them to get what you want and then add them as layers to bring out the data you are after; just a thought.

I like the stars glow and color!

Nice shot.

Sam

Look like it is solid. Let us know how well it works, I am dying to try my AT10RC, but nothing but rain, rain and more rain!!

How do you like the performance of your AT8RC? I've seen some images from others and the stars look pretty good and they say the AT feild flattner will work on the ATRC scopes.

Thanks

Sam

Nice shot, great color, depth and detail. I remember when film shots of an hour or two were really long (hypered-film). Then came CCD and images were just 5-10 min.and went so deep with detail. Now CCD images are 3-12 hours and are way better than what was published in magazines and books from the big scope on film. Who would have thought you could get such a great image with a 5.1" telescope 15-25 years ago. Great times for astrophotography.

Thanks for sharing, it would look great on any wall!!


I only wish the rain would stop.


Sam