Image Acquisition 

Once we have our gear set up for a night's imaging session we need to decide on our target(s). 

I use various sources of information to help me choose which target(s) I am interested in:

• Personal experience and knowledge

• Images taken by other astrophotographers. If you need inspiration then one of the best sources is the plethora of online images taken by fellow astrophotographers. Join an online community and share your work, most people are more than happy to share their experience and advice.

• Published astronomy catalogues such as Messier, Lund's Dark nebulae, NGC, Sharpless.

Once you have a target in mind you need to check if it is available to view in the night sky at your location and time:

• Software apps. There are many apps which you can load on to your mobile phone that give the view of the night sky at your location and time of day. Some apps will suggest possible targets based on your location. The 2 apps I use most are Astrobin and Telescopius, both these sites also allow you to upload your images.

Planetarium software:

• Planetarium software allows us to view our target position in the night sky, and also allows us to frame the target in accordance with the telescope / camera combination we are using. Target framing allows us to rotate the view on screen to best suit the target. Rotating the view however, is dependant on you being able to rotate your camera on your imaging setup. The planetarium software I use is Stellarium. 

We have now chosen our target(s) and checked that they are observable at our location and time, including checking for any elements such as trees and buildings that may block our view.

Its now time to think about how we are going to acquire the images of the target; in other words which imaging setup we are going to use to photograph our target. This will be mostly governed by the field of view we want to capture. From wide field imaging of general areas of the night sky such as the Milky Way, to small deep sky targets such as galaxies, and anything in between such as areas of nebulosity. Generally speaking, for Milky Way shots I would use the DSLR setup, for galaxies and smaller areas of nebulosity the I would use the main imaging rig, and the wide field rig for areas in between.

Image acquisition using the DSLR setup is relatively straightforward. We basically place the camera on a tripod and point the camera at the area of sky we are interested in, focus on a bright star, set the ISO and exposure time. If we are not using a star tracker then exposure times will generally be around 20s, any longer than this we will see star trailing in the images.

Seestar S30. This smart scope gives me built in point and shoot capability, all controlled via an App on my mobile phone. 

The wide field set up and main imaging setup require a more involved image acquisition process. For these I use image acquisition software specifically designed for astrophotography. Again there are various imaging software available; the one I use is 'Nightime Imaging 'N' Astronomy' otherwise known as N.I.N.A. 

Hopefully, now our imaging session has been successful, and we are ready to proceed with image processing.