Sigma 120-300 F2.8 EX DG (1 Viewer)

Hi,

I have just purchased a Sigma 120-300 F2.8 EX DG, sometimes when I have the focus mode on Al servo it wont let me depress the shutter? It works fine in the other modes I lost a few shots today because of this problem, have you heard of this problem? The A1Servo mode works fine on the lens with no Convertors, when I attach the x1.4 its ok but struggles, if I attach the x2 (not the same time as my 1.4) it finds it very difficult to use A1 Servo, but AF is spot on and works as it should do! very frustrating!!

Canon 20d with 120-300mm f2.8 x1.4 &x2 convertors

Chinny

I use this lens with a Nikon D70, and have not experienced this problem. I also have a 1.4 converter and a 2x converter and the lens works fine apart from the slight drop in quality. Hope you get it sorted as it is a great lens.

Alex