Some time ago I got a new telescope – a Celestron 130EQ-MD Newtonian rather than a Celestron NexStar 127 SLT Cassegrain-Maksutov formula. In short, it is more sensitive to light but sacrifices magnification. It’s perfect for deep-space observation like nebulae and galaxies, while the Maksutov is better for observing planets which are much brighter and smaller in the sky. Unfortunately, I found that my Canon DSLR was not able to focus to infinity on the Newtonian so I haven’t been able to take any pictures with it – only observe by eye. That changed when I modified the eyepiece holder to be able to screw further into the optical tube of the telescope, moving the camera closer to the secondary mirror. I also purchased an all-in-one 1.25″ eyepiece to Canon EOS adapter, rather than going down the usual route of using a T-ring and adapter. This also saved a few millimetres. Having demonstrated that I could now focus the telescope and camera to infinity, I collimated it using an inexpensive laser collimator, and got ready to take it to my favourite dark site in Somerset. It wasn’t all that dark as it was a 98% full moon. I wasn’t expecting to take great photos of deep-sky objects but I wanted to have a go with the telescope anyway and familiarise myself with it – the results of the photography were not so important. I started off with a customary photo of the moon which shows that the telescope is doing pretty well at resolving detail, despite having a shorter focal length than the Maksutov.
Then onto the real deal for the evening. Many of the brighter Messier objects were either too near the horizon, or below it altogether, or near the moon. Of the ones that were easily visible on a not-very-dark night, I chose the Andromeda Galaxy, Messier 31.
This is a stack of about 40 pictures. It isn’t a great photo because I was limited to taking exposures no longer than three seconds each, as my motorised alt-azimuth mount has a really annoying stepping motor that causes motion blur every time it steps. I do also have a continuously driven German equatorial mount and next time I shall use that, and hopefully be able to exposure for much longer in each shot. But still, it is a promising first attempt at photography with a Newtonian telescope and I’ll be back out in Somerset the next time there’s a clear night.
Before heading home, I also took a few frames of Caldwell 14, which is a double star cluster. The focus isn’t quite right but otherwise it seems to have come out quite nicely. Again, longer exposures are ideally needed.
Jonathan Gazeley 