I've had this problem before, it used to happen and then back to normal, then the same happens again. Never knew the reason why..
I've had a bunch of hairs in my viewfinder after a trip during the 4th of July vacation and yesterday I decided to clean the focusing screen (which took forever, btw!)
Right now, the focusing screen is nice and clean(er) but the focus points are bugging me..
When the lens is in focus, the red light appears in the viewfinder as a (out of focus halo)..
I've read a couple threads on these forums but no definitive solution was given..
Q: What causes the focus points to produce this halo?
Q: Does cleaning the focusing screen void the warranty? (If I can't fix the halo issue myself, I'll send it to Canon)
Thanks in advance everyone!