Canon 50mm 1.2L HELP!!!

[shesees]

I was SUPER excited to upgrade in the 50mm department.  I got the Canon 50mm 1.2 L series just last week.  I ordered it brand new from Adorama.  I put it on my 5D Mark iii and tested it around the yard (with my chickens).  LOVED the quality!  I brought it out in the field with me to shoot an intimate wedding ceremony (20 guests).  It worked fine for the first 1200 or so shots.  Now every 5-6th image looks highly overexposed.  But the settings are exactly the same as the other images!  NO flash being used.  I haven't EVER experienced this with any of my other lenses (I have a lot).  Any advice?

ISO 1600  F2.8  1/320sec

[shesees]

I haven't had this camera miss exposure for over 6 years, with more than 6 lenses... it seems to me the culprit is most likely the difference/recent change, which is the week old lens.

I did a bunch of testing with multiple lenses this morning.  The only time it happens is with the new 50mm.

[ebiggs1]

"I haven't had this camera miss exposure for over 6 years, with more than 6 lenses..."

This proves nothing except you had good luck with your gear ....so far.  It can fail on the very next shot.

"it seems to me the culprit is most likely the difference/recent change, which is the week old lens."

If you asign it to the lens and it is not the lens a new or different lens will not fix the problem. That is the issue here. Returning it is not your first option.

"I did a bunch of testing with multiple lenses this morning.  The only time it happens is with the new 50mm."

OK that is fine but you need to do the test it on a different or several different cameras.

Then if it becomes so that it is the lens at fault you need to call Canon support 1 (800) 652-2666. A lens sent to Canon will come back better than new as it will have a tech do a through fully functional diagnosis on it.  Way more that the average  off the line lens gets.

[Stephen]

Be nice, Ernie! 😀

[ebiggs1]

??????????? Was that not nice?  It is the correct advice. If it is not the lens at fault replacing it will not help!

[Waddizzle]

I'm surprised that no one has asked this, yet.  What metering mode are you using for the two sample shots?

[jrhoffman75]

OP stated settings are the same.

[Waddizzle]

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@jrhoffman75 wrote:
OP stated settings are the same.

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....and the metering mode is?

[jrhoffman75]

You purchased from Adorama. Why not return to them?

[Ray-uk]

You don't have to keep making exposures to find out what the fault is.

Put the camera in manual mode, look into the lens from the front, hold down the DOF preview button, turn the dial slowly so that the lens steps through each aperture setting in turn. If the aperture is sticking you will soon be able to see it as it won't respond to each click of the dial as it should.

[MikeSowsun]

The EXIF data is available for both photos. The EXIF data is identical for both photos, and they were taken at the same time. 

That means it doesn't matter what the metering mode was, or what shooting mode the camera was in.  All it means is the lens is defective and it is most likely sticking aperture blades.