I was out this Saturday and took some photos. Now I'm looking at them and some have overexposed stripe on the top of the frame. Examples are attached, unprocessed, except resize (raw has it as well).
I was using 6D and 135mm f2 L (no filter, hood on). the only settings pattern I noticed is that its on images taken at 1/1000s or faster (tiny bit is visible at 1/800s, but it doesn't get bigger at e.g. 1/3200s).
I quickly swapped it for 50mm f1.8, did one shot at 1/640s, it was OK, than one at 1/1600s, the overexposed stripe is there...
Any idea what was wrong, what did I wrong?