Astro Photo Question (trying this forum)...

John Retsal wrote:

just Tony wrote:

John Retsal wrote:

just Tony wrote:

Camera is Nikon Z6II with the Z 14-30 f/4 lens.

It’s going to be challenging to set the focus precisely at 14mm. Very little light gets through an entrance pupil of 14/4 = 3.5mm diameter. Use the star Vega, the brightest star nearly straight up at this time of year early at night, and examine your test shots at max magnification. When you see tons of dim stars you have it.

Manual focus mode, manual exposure and VR Off are your friends.

Here are a couple of shots I got the other night. EXIF data included

Oh as for focus, with Z lenses if you disable the setting to remember last focus point, when you first turn the camera on, it's focused at infinity.

At least close anyway. I always check focus if for some reason I needed to switch the camera off - I advise minimizing that. You should also recheck focus as the camera (it's mostly about the lens actually) cools down during the session. It doesn't take much to soften the focus on a star, and it seems slightly off in the second shot.

I did check focus (using rear LCD screen zoomed all the way in) and I couldn't get it any sharper. Also, to avoid any accidental movement, I power off and back on between shots.

Besides focus, I have had some soft star shots due to mist that forms on the front lens element at night at higher altitudes.  Putting a disposable hand warmer on the lens can prevent that from happening.  I am going to try that next time.

That is looks off in the 2nd shot must be an artifact of this website or the device your viewing this on. On my 5K monitor they're both equally sharp.