Aiming and framing with a DSLR
In many occasions you probably are using a DSLR for astrophotography on a mount that doesn’t have GoTo, so you have to find and frame your target manually. To see exactly what your camera is seeing you can make use of the liveview feature of your camera nowadays. This makes it a bit more easy, but you still only see the brightest stars in a relative narrow field of view, depending on the focal length of the lens you are using. Comparing it to a star chart can be done when you know where you are pointing at generally, but if you are off target it is very hard to see ‘where’ you are and how to adjust.
When using my Nikon D7000 on the Astrotrac I used to aim and frame by just ‘looking over the lens’ and taking lots of test images and comparing the image to the star chart of the atlas. I found this to be quite hard so I wanted to have a more easy and accurate way of doing this.
Using a green laser with your DSLR
I got the advise from someone to try and use a green laser to get a better understanding of where the camera is exactly pointing at. You can do this basically in two ways; putting the laser alongside your lens or pointing the laser in the viewfinder. Both methods proved to be to inaccurate to be really useful.
So I had to think of another way.
Using a red dot finder with your DSLR
Turned out you can easily mount a Red Dot Finder on the hotshoe of your DSLR! This makes it very easy to see exactly where your camera is pointing at because of the bigger overview you have of ‘where you are’, so you are able to ‘star-hop’ with your DSLR.
The only thing you need is a small adapter to put on your hotshoe. There are several online stores that sell these. I got mine at Teleskop-Express (in Germany) here: Lacerta flash shoe finder adapter
With this adapter you can easily mount your red dot finder on your DSLR. I even use this when shooting with my Quadruplet, it’s just so convenient.