HELP Camera/Lens Problems

[shanmclean87]

Just last night I've begun having some problems in low light conditions where there is a strong source of light also in shot. As you'l see below, it's a relatively dark setting but with the bright bulbs in the top of frame. You may have also noticed that there is a greenish reflection effect appearing in the lower part of the shot. What would be causing this!??? I'm shooting with Canon 70D lens 1.2 50mm. I did a few test shots this evening in my home using the same lens and at a setting of 4.0f
 60 shutter speed and ISO 400 I got the same results. However, when I switched to a different lens and used those exact same settings it did not happen.. so I take it this means there is something wrong with my lens!? 

Any help/advice appreciated. I'm not really sure where to take my camera and lens to get looked at and repaired. I haven't even had this lens for a year, so it should still be under warranty? I have not dropped or hit it at all so I can't imaging what is causing this.

[Waddizzle]

You have not posted in the best forum for help with lens issues.  The true lens gurus rarely visit this forum. It is not clear what lens model you are talking about, either.  Is it the EF 50mm f/1.2L?  Are those incandescent lights, or some other type?

What I see looks like a reflection, or artifact, of the bright lights.  If you're using a lens filter, try shooting without it.

[jrhoffman75]

It's definitely a reflection. It could be from a filter or it could be from the rear of the lens.

From web search:

[ebiggs1]

You have what seems to me to be a odd combo.  A 70D and a ef 50mm f1.2L lens. Correct? The ef 50mm f1.2L is probably the most difficult Canon lens to learn how to use properly.  I really love that lens but I don't recommend it to people not wanting to spend the time to learn how.

The ef 50mm f1.2L requires a protecto filter to complete its weather sealing. This filter must be of the best quality for a lens at this level. Example for a good but inexpensive filter is the B+W Clear MRC 007M Filter at about $50 bucks.  There are even better choices. If yours isn't in this quality level trash it.

I can't see where it is the reflection of the lights but I can't think it would be anything else. I guess the lens is fine when used outdoors on a nice sunny day?  No issues?  And there are no issues when there are no lights? No issues with any of your other lenses?  Have you tried the 50 on a different camera?

[jrhoffman75]

Very clear mirror image reflection. Upper left goes to lower right.

[Waddizzle]

"I can't see where it is the reflection of the lights but I can't think it would be anything else." 

What I find most curious about is that the "green lights" appear to be double reflected.  They are a double mirror image of themselves if you mirror the light image using a reference line down the center of the image both horizontally and vertically. 

I don't see how a single filter, screwed onto the front of the lens, can cause that double mirrored effect.  I think John's right.  It's probably reflecting off something(s) inside of the lens.

Another curiousity is that the lights themselves seem to have green fringing on them.  Not what I would expect from an "L" lens, but who knows with bright light sources.

[ebiggs1]

"I can't see where it is the reflection of the lights but I can't think it would be anything else." 

Mine does not do that or at least I have never seen it do that.   "I can't think it would be anything else.", as I said.

 Only admitting that because I can't think of anything else it would be.  If it is those lights does everything have to be in a certain place to cause it?  Or does it happen on any bright light?

[jrhoffman75]

Based on the tecnical info I found and posted in Message 3 it looks like a combination of conditions. The bulbs are very bright and the reflections are more visible against the very dark jackets. Very wide DR. Reflections are less visible against lighter clothing and probably wouldn't be visible on a more evenly lit/exposed sceen.

[ebiggs1]

" Reflections are less visible against lighter clothing and probably wouldn't be visible ..."

Possibly but that doesn't mean they aren't there.  I have not noticed anything like that in mine and I have had it for a goodly while.  It is not an easy lens to use.  I also have its twin, the ef 85mm f1.2L and it doesn't do it either.

My estimation is these are two of the best lenses made by any company. 

[Waddizzle]

This is an illustration of what I meant by "double mirrored." 

The original lights are represented in red.  The "mirror line" runs horizontally through the center of the image.  Green is the result.

The green output is now mirrored again, but this time vertically.  The blue lines are the output, similar to the original image.