ASTRO: Aurora and Question

The aurora from outside Calgary last night. Ruined by the rings in the
middle of the photo as have shown up the last few times I have been able to
shoot the Northern Lights. Can anyone tell me what causes them. These
rings show up nowhere else day or night.
jim
Using T2i and kit 18-55 II lens

On 9/10/2011 12:53 PM, jim wilson wrote:
The aurora from outside Calgary last night. Ruined by the rings in the
middle of the photo as have shown up the last few times I have been able
to shoot the Northern Lights. Can anyone tell me what causes them. These
rings show up nowhere else day or night.
jim
Using T2i and kit 18-55 II lens

Nicely done with the light of a near full moon. Forecast is for more
the next couple nights.

I've seen this due to moisture condensing in the camera. Not sure if
that's your problem or not. Might remove the lens and let it dry for
some time in a dry environment. If your nights have cooled 25C as mine
are now this could be the problem. I also had an oil film from source
unknown do this. Both back in my film days.

Rick

--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

On 2011-09-10, jim wilson wrote:

The aurora from outside Calgary last night. Ruined by the rings in the
middle of the photo as have shown up the last few times I have been able to
shoot the Northern Lights. Can anyone tell me what causes them. These
rings show up nowhere else day or night.
jim
Using T2i and kit 18-55 II lens

Beautiful picture.

The rings look exactly like the Newton's Rings I can see in the objective
of my 4" achromat under the correct illumination, when viewed from the
front. You get them where there are two closely spaced lens surfaces.
Is there a filter on the lens, close to the front lens element?
Otherwise, my guess is that they're from a pair of closely spaced,
air-spaced elements inside the lens.

Bud

wrote in message
m...
On 2011-09-10, jim wilson wrote:

The aurora from outside Calgary last night. Ruined by the rings in the
middle of the photo as have shown up the last few times I have been able
to
shoot the Northern Lights. Can anyone tell me what causes them. These
rings show up nowhere else day or night.
jim
Using T2i and kit 18-55 II lens

Beautiful picture.

The rings look exactly like the Newton's Rings I can see in the objective
of my 4" achromat under the correct illumination, when viewed from the
front. You get them where there are two closely spaced lens surfaces.
Is there a filter on the lens, close to the front lens element?
Otherwise, my guess is that they're from a pair of closely spaced,
air-spaced elements inside the lens.

Bud

Yes there was the usual filter and I was going to remove it but I...forgot.
I'll kick myself if that is the answer. Forecast is for more auroras
tonight so hopefully I will solve the problem and get some better shots.
jim