I've been seeing these spots from time to time in some of my images, and I was starting to think that I had dirt or something on my sensor. My 7D has the auto-clean cycle that runs every time the camera is turned on and off, plus I've run the manual internal sensor cleaning cycle a couple times. I was all set to either clean the sensor myself, or take it to a shop for cleaning, when I noticed the spots where not there when I used my 100mm lens the other day.
So I ran a little test... I took a photo with my 100mm macro, then with the MP-E 65mm at 1x magnification, then a couple at 5x magnification. Sure enough, the spots only show up (at least that I can tell) when I have the lens at 5x magnification. The spots are always in the exact same locations, so whatever the problem is, I don't think it is going away.
Does anyone have any ideas what these might be? I just want to have a pretty good idea of what is happening before I go about trying to get the seller or Canon to replace the lens...
I just took photos of a piece of paper real quick to illustrate this. Is there something better I should use to illustrate the problem?
mp-e 65mm at 1x:
mp-e 65mm at 5x:
Any and all help is greatly appreciated!