Double images of the moon, bad seeing?

[ColinRM]

Hi everyone!

I'm just starting out with astrophotography.  I have a SkyWatcher 12" dobsonian and a Nikon D5300.  I've been playing around with taking pictures.  The camera is mounted in "prime focus" with a 2" T-adapter.

When I've tried photographing the moon, I seem to get these weird double images.    At first, I wondered if it was trailing or something, but the exposures are short, between 1/20 and 1/80 of a second.  The double image also seems to move around when I take a quick burst of four to seven pictures, so I'm thinking it's not something with the telescope's collimation. 

Visually, everything looks great, and I can't notice it.  I've tried some short eyepieces, but everything still looks great in those.

I attached a couple of pictures that show several images that were taken in quick succession, using the burst mode on my camera.

I'm wondering if anyone has any ideas on what I might have wrong.  Is the focus just not quite there?  Is this what bad "seeing" is?  Could it be camera mirror flap?  Maybe my collimation is not quite perfect?

I've had it happen on two different evenings in two different states.  One evening was nice, about 55F and patchy clouds.  The other night was cloudy and very cold.  Maybe 20F.

Thank you for any advice!

[happy-kat]

Hi

What are you using to trigger the camera?

[paul mc c]

looks like vibration....was it windy.

[ColinRM]

I have the camera hooked to a laptop for triggering it. 

I didn't recall it being windy, but I'll make sure to make note of that next time. 

I'd give the telescope at least ten seconds to settle after moving it. Maybe that's still not enough time?

[david_taurus83]

Can you set the mirror to lock up before the shutter activates? Like a couple of seconds before? It does look like vibration.

[Phillips6549]

Are you shooting Raw or Jpeg? If Jpeg have you got HDR turned on, taking multiple images? 

[ColinRM]

1 hour ago, david_taurus83 said:

Can you set the mirror to lock up before the shutter activates? Like a couple of seconds before? It does look like vibration.

The mirror doesn't lock up, I looked into that before. Perhaps I can hold it open mechanically. 

[ColinRM]

1 hour ago, Phillips6549 said:

Are you shooting Raw or Jpeg? If Jpeg have you got HDR turned on, taking multiple images? 

I'm doing just Raw files. I know I turned HDR mode off, but maybe there's something else doing the double exposure.