Monday, September 15, 2014

Dumbbell nebula, Ring nebula and exposure tests

The sky was clear on September 13th and I planned to shoot some stars before Moon rises. I thought I had prepared everything, but turned out I hadn't charged cameras battery. Luckily there was enough power to last until Moon lit up the sky. Maybe 15 minutes more had been possible but nevertheless... everything went better than I expected.

First some more tests about exposure times. 80 second was easily possible the last time, now I tried some more.

100 second exposure (left) and 150 second exposure (right)
100 seconds looked good so I took 150 second. When I look at the photo on computer screen I'm not sure about 150s. Most stars look ok, but maybe some show some trailing. I have to run final tests about this on a better ground. This time the mount was a bit unstable. So I'm not sure whether the trail is caused by mount shifting on ground or incorrect alignment.

Result was something between 100 and 150 seconds so I chose 120 as exposure time for shooting the Triangulum Galaxy.

Triangulum Galaxy M33



This failed. Moon was rising and it's glow had lit the eastern sky. Air humidity was also quite high and some fog did form a while later so all that made Triangulum a wrong target for that night. Still I spent 10 x 120 seconds worth of time and battery on what you see above. Also I managed to tilt the camera couple times so only seven photos were usable.

Well... You can see it and maybe even recognize it as M33. Bigger photo (if really necessary) in https://www.flickr.com/photos/96700120@N06/15063242487/

Ring nebula M57

After the Triangulum failure, I realized the sky was more clear of light pollution right in zenith. Lyra and Ring nebula was the first thing that came in mind. Couple of photos there and only one of them was not tilted during exposure. I really have to stay away from the mount during shooting...


This is a single 120 second exposure. Quite nice. Although focal length of 200 mm is quite short for M57. Bigger photo in https://www.flickr.com/photos/96700120@N06/15063241107/

Dumbbell Nebula M27

Battery indicator was blinking red but I thought I'd use all the remaining power to shoot the Dumbbell nebula. It was also in a dark spot of the sky. Now the exposures are only 30 second and I took 10 of them but still this is what I got:


I'm impressed. Last time I tried M27 was with my old 75-300/4-5.6 zoom lens. I got a faint gray smugde. Now the aperture was 2.8 and my faint smudge has some real color! Can't wait to take some longer exposures of this.

Here's one a bit zoomed to show in the preview on Facebook or G+. :)



Bigger photo in https://www.flickr.com/photos/96700120@N06/15048413067/ and one with more stars around it in https://www.flickr.com/photos/96700120@N06/15047931927/. There's also open cluster of NCG6830 on the bottom if this image.