Some bad reflections.

http://img.photobucket.com/albums/v3...e/_MG_7153.jpg

What is the cause of that blur? Could it be my filter? I'm using a cheap $40 UV filter till i have $ for a quality one.

*I overexposed for the effect of the unshown moon part. Just curious.

It doesnt show in my shot of the moon without an overexposure.

http://img.photobucket.com/albums/v3...e/_MG_7156.jpg

Thanks for reading and helping me out!

This looks like it might be a reflection off your IR sensor bouncing off your inside lens element onto the CCD again. If it doesn't show up under normal exposure then it's not too much of a problem.

I'm not 100% sure on this, but its my educated guess.

Tim

it moves when I turn my camera from side to side, if i position the moon center, it shows center, if bottom left, it shows bottom right, and such.

I was thinking that as a second possibility, but the way that the reflections went, I think your idea is more possible.

Cheap filters are notorious for this. Plus, bright light, dark background... That's asking for trouble. Take off the UV filter and try again. It's useless anyway!

Yep, it's the UV filter. Light bounces off the front element and shows up on the back side of the filter. Strange that it doesn't show up at all in the other shot though.

A good one probably won't make that much of a difference. I don't use them unless I'm pretty sure I'm going to get stuff (like rain) on the lens. A lens hood will give you protection plus it can also help in a case like this.

I'll give it another shot without the filter tonight if I can find the moon. Its going below the horizon so early around this time of year, really a bother when you have a brand new 400mm, haha.. :-)

*and with a $1100 lens, I dont want to scratch the front element at all... You guys say a higher grade filter wont matter much more than a cheap one? Hrm..

Quote:

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Originally Posted by SpeedingSphere

You guys say a higher grade filter wont matter much more than a cheap one? Hrm..

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Not in this case - maybe a slight improvement but that wouldn't help. You have a really bright subject that's not symmetrical and in the middle of the frame. You wouldn't see the reflection this way, but really, how many interesting photographs can you make that would be like this? :) In some more "normal" situations a multi-coated filter (Hoya HMC is good), that coating would take care of the problem.

Ok, thanks for clearing that up for me. I was just fooling with the shot and tried to get the 'dark side of the moon' and came up with a strange reflection.

The moon should be up in 2 hours or so, so I'll take another shot then.

Thanks for the replies!

I was using a cheap filter at le Mans last year and had the same problem with car headlights.
I've stopped using UV filters, even the Hoya SMC Pro filter produced some reflection.

What filter do you recommend I use over the front to protect, and have no glare? Clear filters? Will they provide reflections? Thanks again!

Given harsh enough light conditiosn (like this moon) almost any filter will reflect, even a super multi coated "professional" filter, particularly if you over-expose the highlights..
I have always used the top quality Hoya filters, but will remove them for night time.