>>2655552Landscape, you can work with. It ain't gonna be super-great, but you can get something. Deep-sky objects? Not a chance, without buying more equipment.
the most important things:
Be in a dark place. That means 100+ miles away from any major city.
Camera on a tripod. You cannot hand-hold this.
Open wide. For you that's gonna be 18mm and f/3.5. Your lens ain't the greatest at the wide end, wide open, but its what you have.
Crank up the ISO. As high as you can go without it being a noisestorm. Prolly in the 1600-6400 range for you.
choose a shutter speed by the 500 rule. 500/35mm-equiv focal length = max time before stars form trails. For you thats about 15 seconds.
Focus at infinity and disable AF. AF is useless for this.
Use a remote shutter release, or the self-timer if you don't have one.
Something in the foreground? Take a shot focused and exposed for the foreground, and another focused and exposed for the stars, shoop them together.
If you decide you like this and want to get more into it you will need:
Star-tracking. Available as both simple equatorial trackers (iOptron star tracer, Vixen Polarie) that mount on a regular tripod (have a good, stable tripod with a nice head, btw) and as expensive dedicated telescope mounts. This lets you take long exposures without star trails.
Better optics. For landscape, you want a fast wide-angle. The Samyang 24/1.4 and 14/2.8 are good places to start. For deep-sky, you want either a telescope on a good mount, or a long telephoto on a good mount. The mount and its tracking accuracy are MUCH more important than the lens or body for deep-sky.
Time. Be prepared to take dozens of multi-minute exposures and then combine them in software, if you want stunning pics of galaxies and nebulae. Along with dark frames, flat frames, bias frames, and such. You will be spending a lot of time and computing power post-processing.
