Friday night was clear and the temperatures were pleasant, so I stayed up to play with my camera under the stars. However, rather than open the observatory and tie everything to the telescope I decided to try imaging with the regular camera lens on a simple tripod. The idea was to take pictures every ten seconds and build a movie from that. The camera timer/remote control can only take up to 99 frames, so the maximum time for each imaging session was only 15.5 minutes, and the resulting movie at the end of a session is just a few seconds long. Next time I’ll use a laptop to trigger the shutter so that I will be able to image in longer continuous runs.
I grabbed the frame sequences without particular difficulty, but combining them into a movie at full resolution turned out to be more of a problem. Most of the software I googled would not take jpeg input, but instead expected to receive images directly from a video camera. About the best of the lot was AnimaideXT which was able to read in the jpegs but like the others it expected to produce output as video, and reduced the size of the images. That’s acceptable in, say, a time-lapse image of the observatory (rather fun to see the shadows whipping around) but not of a series of astronomical images.
I’m still working on the images, but one thing was interesting – I combined the frames using Nebulosity to sum up 35 images of the area around delta Cygni, imaged through the 17-85 mm lens at 85mm f/7 or so and ISO 1600 for 3 seconds. I was curious as to how faint I could get, and was surprised (but pleased) to get down to magnitude 10.
This is a small section from the region around HIP94336 (the brightest star at magnitude 5.84) , and stars at least as low as 10.6 can be discerned (the original image may show slightly more stars – it’s a judgment call).
For comparison, here is the same area from Starry Night 4.5 adjusted for the same orientation (the image was scale adjusted to match the SN map as closely as possible).
From a series of 3-second exposures on a regular photographic mount, I’m impressed.
More on the time-lapse later….