Infinity focus issue with NX300 in night shots

Well, manually focusing to infinity with NX300 wouldn't work, because it can actually focus a bit 'beyond' infinity (I think it's needed for contrast AF to work). What you need to do is set the focus assist (magnification) to 8x in the menu, then focus to infinity and rotate focus ring few degrees back to get stars in focus. The magnification should help you and you can find some bright star to focus on. But it's not straightforward 'focus to infinity and shoot' affair. You might need to try it few times, before you get the focus nailed. When you do, just try not to touch the focus ring and you should be good. Or, as already mentioned, you can try to focus on something else (Moon or some other distant object). But you can do without it. I was actually able to get some decent shots of Milky Way with NX200 and 16mm lens (f2,4, 30 seconds exposure, ISO 1600), but it took me a while to figure it out and set up. As I said, lots of trial and error, but can be done.

Thanks WMT will give that a go next time I venture out

One downside of fly by wire lenses is that you can’t mark the best position for any given distance so to some extent judgement is needed. However I have taken a close look at your images and think you have other problems. If you look at 100% you can clearly see a double exposure on each star. So I would look at the rigidity of your set up. I don’t do star photos myself but I do know that the camera has to be rock solid to pull them off.

I would recommend using MF assist with enlargement set at 8x then set up your display so that you can clearly see at least one star.  To accomplish this try Framing mode, if that doesn't work put it back in regular mode and elevate the iso to an unacceptably high level (along with shutter time at 30s and aperture at it's largest).  This will allow you to focus on a single star directly using Manual focus.  Once you have set the focus put your iso back down and put the other settings where ever you want them to be.

I have gotten some very clean night shots with my NX300 I've even started doing some star trail sets (requires interval shutter controller).

Cool thanks for all the answers

Will be sure to be back once I get time to hang out down the garden and try some of the tips out

Okay so had a clear evening tonight and the moon was out and getting much better pictures, but capturing a few light trails from planes reveal a further improvement that I need to make.

i.e. Use a 5 second or so timer to let camera settle down, from the wobble of the shutter press

OR

Invest in a remote shutter switch, which would also let me use bulb mode

The tips about focus really did work well.

See start of plain trail for the effect the shutter press has

Another example of judder

Might pop out again later and see how much better I can get

OK 10 second shutter delay and 30 second exposure, and short star trails, so presume this is down to the earths rotation.