Over the past few months, I’ve been getting increasingly into astronomy. Initially I wanted to start with just a telescope, as I spend a lot of time during the day working on computers so I didn’t really want to spend more time as part of my new hobby.
Recently, however, I’ve started to get interested in astrophotography. My current set-up is pretty straightforward; I have an STF Mirage 7” telescope, mounted on an EQ-5 mount with the Skywatcher dual-axis drive system. When I’m taking photos, this is coupled to a Canon EOS 400D DSLR camera; currently I have adapters for eyepiece projection and prime focus photography (I realise that this is backwards; normally people start with piggy-back set-ups because they’re easier and you can get some good photos that way, but I don’t have a suitable bracket for that yet).
As my scope has a focal length of 1800mm, I was pleasantly surprised to discover that, at prime focus, the EOS camera gives almost the same field of view as my 25mm eyepiece (it’s a bit smaller, so I can’t quite fit the full moon into the frame in the camera whereas it does fit into the field of the 25mm Plössl eyepiece).
Anyway, I was quite pleased with my second attempt at photographing the Great Nebula in Orion:
This was generated from a stack of 50 or so photographs of around 10 seconds each at ISO 800. Some tweaking was necessary to get the image to look like this; my camera is a stock EOS 400D, rather than an astro-modified one, so it doesn’t capture the nebulosity as well as it might. That said, I’m very pleased with this picture.
I also had a go at capturing Saturn using eyepiece projection, but sadly I couldn’t seem to achieve good focus with the Barlow lens in the system. The CMOS sensor in the camera is definitely in the focal plane for some setting of the telescope’s focuser, because I can defocus on both sides (i.e. I can turn the focus knob until it looks focused in the viewfinder, and I can then continue to turn it in the same direction until it defocuses again). Of course, with a Barlow and the T mount adapter for the camera, it’s getting a bit silly with everything hanging off the end of the telescope, but I should still be able to take reasonable pictures of Saturn I think as it’s quite bright and therefore doesn’t need long exposures.