09-14-2020 12:33 PM
I'm surprised that no one has asked this, yet. What metering mode are you using for the two sample shots?
09-14-2020 12:43 PM
OP stated settings are the same.
....and the metering mode is?
09-14-2020 01:16 PM
"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.
09-15-2020 11:48 AM
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.
09-15-2020 12:39 PM - edited 09-15-2020 12:41 PM
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.