Comet Lulin, March 2009

I took the picture above with my camera mounted on the telescope in place of the eyepiece and the speed cranked up to the maximum of 1600 ASA. Two 30-second exposures were combined in Photoshop Elements, in an attempt to improve the picture quality.

I managed to get four decent pictures that evening, and tried combining them all. In theory this should halve the noise, but the comet was in a visibly different position from one picture to the next. This gave me an idea.

On Wednesday 4 March I took 50 pictures, one after the other, and combined them to make the video shown below. You can see the comet moving, and just about make out the tail. The stars in the background drift also, but that was because the telescope wasn't tracking the sky perfectly.

[EDIT - In 2020 I merged the photographs into seven groups of seven using the stacking software Sequator, as shown below, one on top of the other. Click on "Play" to cycle through them.]

The following evening I tried a new tactic. The "bulb" setting on the camera was used to give a longer time exposure. Several pictures were taken, some of which came out blurred. The one below was the best. The exposure was 93 seconds. The sky looks blue, as the Moon was nearby. In fact, the comet was so faint next to the Moon that it was barely visible with my binoculars and I couldn't see it at all through the telescope finder or the camera viewfinder.