I have a question for users experienced with fast primes. Today, I tried to test AF with my 700D (T5i) and my two lenses:
- EF-S 18-55mm 3.5-5.6 IS STM
- EF 50mm 1.8 STM
I noticed an issue with the 50mm. When I open up the aperture to the max, the AF jumps a bit on every other photo.
But...
Today while I was cleaning my Canon 50mm 1.8 STM lens, I noticed by using the DOF preview button that when it was on f22, there were some visible streaks or oily marks on the aperture blades. I don't know if this is normal, or if this is the way this lens was designed, or if I did something...