Problems with SigmaAPODG 70-300mm

[Roger Beaumont]

Hello... and Help!

I use a Sony@ 700, which is fine. I also use a wide angle plus, a 18-70mm lens - both Sony lenses - which are fine.Then, I bought a second hand Sigma APO DG 70-300mm. Great lens, great shots. But after 2 months, whenever I connected lens to camera, there was this terrible grinding sound and the focus was shot. I had it fixed. Very soon the same problem occured. As it was second hand, I reckoned ok, maybe I was sold a dud. SO, I bought a brand new Sigma APO DG 70-300mm in June this year and the same *&%!!!ing problem has started again!! A grinding sound when lens is attached!
Can anyone pls explain why this is happening? I am on the road all the time and we all know that warranty's are useless once outside the country you bought the kit....any ideas or suggestions about why this lens is a problem - or any other suggestions would be really appreciated. I am now on asignment in Bhutan and one important lense done! Btw, has anyone else had this problem? Best regards, Roger Beaumont

[DonSchap]

Roger ... I have some really bad news for you ... the SIGMA 70-300 is rather notorious for this very problem ... as the focus gears strip out and leave a very clever looking "notch" where there used to be gear teeth, inside the lens. The torque from the SONY focusing motor is too much for the lens.

Try a TAMRON AF 70-300mm f/4-5.6 Di LD (<-click on this link) lens and stop torturing yourself. For roughly $160 ... you will be good to go and no more of this tomfoolery with gear stripping.

Good luck and there's your answer.

[Roger Beaumont]

If this gear stripping is so prevalent in this Sigma lens, why isn't eveyone suing Sigma? !

[fstopMike]

I have the same lens mated to my D40X. I bought it in April and use it a lot. I've not had any problems so far.

[DonSchap]

Originally Posted by fstopMike

I have the same lens mated to my D40X. I bought it in April and use it a lot. I've not had any problems so far.

And I suspect you will not. The problem is with the SONY's high torque focusing motor. You won't get that kind of snap out of a Nikon.

[welshmaverick]

I have the Sony A200 and most people think its only the A700 that strips the gears on this lens, but i can tell you its not. My Sigma lens is only 11 months old and i use it about 4 times a month. It has just been sent to Sigma for repair !!

Mav