Just want to share this. I bought 10 years ago a used 24mm f2.8 on ebay. Not bad condition but when I tested the lens on my 20D, the lens was very very soft. I've never really used it. Then last year I tested it on my newer t3i and worst, the lens showed some nasty doube edges in the highlights, a real dog. biark.
I've just tested the lens on my 6D and, behold! It's not bad at all. Then to compare I mounted my 15-85mm (at 15mm) on my t3i and the 24mm on my 6D and took an indoor comparative shot; The 24mm is just as sharp as the 15-85mm. Obviously the ISO noise and full frame resolution make the difference here. One surprise though, the 24mm is wider by a fair margin. I would say a good mm.
I've just won myself a very usable lens! Pretty happy about it and I'm going to bring it tomorow on a little trip.
That's all! Happy happy joy joy!



