Q&A: What Are These Spots in My Night Photos?
I am a casual photographer and recently bought my first digital camera. I am enjoying my experience with the camera, but I have a problem. Sometimes I get small, semi-transparent white circles in my pictures when I shoot outdoors at night. Can you tell me what is causing them and how to avoid them?
--Shahul Ahamed, India
It sounds like you're seeing the effect of lights reflecting into the lens, Shahul. You won't generally see this in the daytime, because only the sun itself is bright enough in daylight to cause this effect. At night, though, you can easily get this effect by shooting outdoors where there are lots of different light sources. If you have a good camera, its optics should minimize this problem, but inexpensive cameras are more susceptible.
So what can you do? If your camera has screw threads on the front, I suggest adding a UV filter that will reduce glare. And if your camera came with a lens hood, attach it to eliminate glare coming in from the sides--or fashion your own and mount it to the front of the camera. If those suggestions don't help, the only way to avoid glare is by not shooting outdoors in the city at night--at least until you upgrade your camera.