I'm sure there is a reasonable explanation for this but it escapes me. The other day I was hiking around Mont Blanc. Although the weather was mostly uncooperative, I did get up at 4 am during a break in the clouds and took a few nightscapes. This one is not very sharp, and upon closer inspection it looks almost like a double image. Here is the full frame:
And here is a 100% crop. If you look at the star trails you can see two parallel lines for each one, brighter above, slightly dimmer below.
First of all, please don't judge this on my lack of fine tuning noise reduction. I am new to this camera and have yet to find my comfort zone above base ISO. Here are the stats:
RSS TV24 w/ just the swivel base; no ball head
Leica APO 50 summicron Asph
2 sec time delay
10 sec exposure
- 1 ev exposure
This cannot be camera shake because both star trails are continuous for each star. I think the camera would have to be oscillating quite fast between two identical positions for the entire 10 second exposure to produce this by shaking, no? I double-checked EXIF in Rawdigger - image stabilization was off. To confuse the issue more, here is another photo a few minutes later with the Loxia 35 f/2:
And again a 100% crop.
No double image. So whatever it is it was associated with that camera/lens combination. But I cannot get it to repeat the problem! I've taken several images this morning to verify the APO 50 is indeed still as sharp as you would expect with no "double images".
It might be possible that I did not have the lens shade extracted. The moon was overhead but nowhere near the edge of the frame.