What is this green thing???? Rho Ophiucus

[batema (Mark)]

Hi,

Have I discovered something or is it a water drop causing this anomaly in my image. Bottom right I have a very green object in all my images of this object. Any ideas?

Mark

[gregbradley]

Looks like some sort of artefact and not real. Perhaps some junk on your camera or filter?

Greg.

[janoskiss (Steve H)]

Please keep your junk out of my oppressed sign of the Zodiac! Unless it's Comet 252P that was lurking in the general vicinity not so long ago. But six weeks seems like too long for it to hang around...

[multiweb (Marc)]

I can't see the green you are talking about. Is that the yellowish stuff next to Antares. I think that's normal. Great widefield Mars and Antares in one.

[RickS (Rick)]

Did you sneeze on the camera, Mark?

[RB (Andrew)]

Mark it could be an internal reflection in your lens.
Were you using a (prime or zoom ?) 200mm.
Perhaps with a UV filter attached?

RB

[h0ughy (David)]

i agree with RB - its antares alter ego

[batema (Mark)]

I am using a Canon 200mm L f2.8 prime with a UV filter attached to the front.

Mark

[RB (Andrew)]

Originally Posted by batema

I am using a Canon 200mm L f2.8 prime with a UV filter attached to the front.

Mark

That's it, just as I though (houghy too).
The UV Filter will do that, causing a (usually green) internal reflection off the back of it.

I always have high quality UV filters on all my lenses but I take them off when doing astro.

RB

[batema (Mark)]

I'll do the same. Thanks.