Only at night

[marist89]

So I've been playing around with my Nikon D90 at night. This strange blue dot showed up in my photos, but I didn't see it through the viewfinder. It showed up on most of the pictures, but didn't move so I'm pretty sure it's not a plane. Any ideas? Maybe dirty lens that reflected light? Oh, all my images appear clean with natural sunlight.

f2.8 @ 4 second exposure.

[OldClicker]

I would guess that it's lens flare from the bright area (moon???). - TF

[marist89]

Yes, I think you are right. I didn't realize the moon was that bright. I took some pictures of stars and didn't see the same. Next time I have a bright moon I'm going to try to close the aperture down and see if that helps.

[mjs1973]

Do you have a UV "protection" filter on your lens?

[marist89]

Do you have a UV "protection" filter on your lens?

First one, no. Second one, yes, I forgot to take it off.

[mjs1973]

The reason I asked is because filters can cause ghosting, and flair, especially at night with a bright light source.

[marist89]

Right, thanks!