Hi there - for once in my life i decided to buy a Tamron 28-75 2.8. The thing is i sold my canon 24-70 2.8 to be able to affort a 70-200 2.8 USm thinking i would never miss the middelrange zoom again . A month later i did just that. Reading many many reviews i bought the 28.75 lastweek. Once i had it i did some test shots on my 5D and i couldnt get the Autofocus to focus on eyes when using multible focuspoints on either Aifocus, servo or one shot. Insteat it focused on nose, eyebrows - the things that sticks out (hope you understand) . when focused manually i could get supersharp images. I suspected that it had a frontfocus problems when using 5D multible focuspoints. However when i set only the centerfocus point focusing on the eyes it really made good sharp images also on 2.8. So i found this focusing chart a made some tests using only the centerfocus point , blew it up to 100% and everything , i think looks nice. Ive posetd some test images wanting you to see what you think. all shot on 75 mm : 1) 8.0. 2) 5.6. 3)4.0 4) 2.8. all with flash and 5D set to oneshot.. Should i keep it or should i get a replacement. (Really the thing is i dont understand why i dosent work on multible focuspoints as ive allways used on my other lenses. Or maybe im not using my AF correctly. Thanks for havig a look .