Sigma 500mm on Canon 50D

Falconer2406 · #1 (**permalink**) 23-10-2011, 08:50 AM

Hi all recently purchased a second hand Sigma 500mm f4.5 and am having serious problems with it on my 50D body. The lens /body combination flatly refuses to autofocus no matter what i try. I contacted the seller who told me i needed to switch to manual focus give the focusing ring a twist and then switch back to autofocus and this will connect the two together and in fairness it did initially seem to get it working.
However i switched camera off and now when i switch on again nothing i do can get it to work. The seller has shrugged his shoulders and walked away stating that he has taken 100,000 photos in three years with the lens on a 1ds without a problem

I have several other Sigma lenses and also a 350D body and all combinations work flawlessly so i therefore rule out a body issue.
Has anyone any ideas at all, is there a setting on the 50D i need to use that i'm unaware of?
Any help or advice would be greatly appreciated.
Keith

GTH · #2 (**permalink**) 23-10-2011, 10:49 AM

In my opinion there should not be a problem, so leans itself to being the lens that has a fault. I have the Sigma 300 2.8 and have never experienced such a problem. Have you thought of contacting Sigma at Welwyn Garden City to check it out ? I heard from a friend who had "sharpness issues" that they were very helpful.

Sorry i can`t be of more help. Best of luck,

Geoff

redstart1 · #3 (**permalink**) 23-10-2011, 06:02 PM

Hi, im using a sigma 150-500 lens on my canon500d and have no problems with focus, have you tried your lens on your 350d to see if it works, if not it is the lens that is at fault.

Geoff F · #4 (**permalink**) 23-10-2011, 08:03 PM

Just a thought, Keith, but have you checked for dirty contacts on the lens or camera? Just rub a piece of clean white paper over them.

Otherwise, I would be worried.

If the lens has taken 100,000 shots then it has certainly had plenty of use.

And having worked OK in the past doesn't really mean anything. I have had lenses which have worked well for many years - until I dropped them!

johnf3f · #5 (**permalink**) 24-10-2011, 10:35 PM

Quote:

Originally Posted by Falconer2406

Hi all recently purchased a second hand Sigma 500mm f4.5 and am having serious problems with it on my 50D body. The lens /body combination flatly refuses to autofocus no matter what i try. I contacted the seller who told me i needed to switch to manual focus give the focusing ring a twist and then switch back to autofocus and this will connect the two together and in fairness it did initially seem to get it working.
However i switched camera off and now when i switch on again nothing i do can get it to work. The seller has shrugged his shoulders and walked away stating that he has taken 100,000 photos in three years with the lens on a 1ds without a problem

I have several other Sigma lenses and also a 350D body and all combinations work flawlessly so i therefore rule out a body issue.
Has anyone any ideas at all, is there a setting on the 50D i need to use that i'm unaware of?
Any help or advice would be greatly appreciated.
Keith

Which 1DS was he using? Mk1/2/3 - they all have different AF systems.
Sigma "Reverse Engineer" their auto focus and there can be compatibility problems with their older lenses on newer cameras, especially Canon. I don't know whether this is because Sigma will not pay royalties to Canon or if Canon will not release the software to them. I suggest you contact the seller again ( and perhaps trading standards?) also contact Sigma - they may be able to help by "Re-Chipping" the lens to bring it up to date.
Good luck and, for the future, try before you buy.

cosmicma · #6 (**permalink**) 26-10-2011, 03:06 PM

when you say by turning the focusing ring you can/could persuade it back into life it sounds to me as if the focusing motor within the lens is faulty
i don't think it's a chip issue as they tend to throw up an error with the camera ( error 99 usually ) or only work wide open like the old sigma 105 f2.8 macro lens

i think all suggestions on what you can do about it have already been said but if you get no joy with the seller then it's off to sigma repair i'm afraid

Falconer2406 · #7 (**permalink**) 31-10-2011, 10:12 PM

Just to close this off, the problem turned out to be a faulty HSM a quick £200later and all is well.
Thanks to those whom replied and offered help and advice.
Keith

The_Moaner · #8 (**permalink**) 31-10-2011, 10:52 PM

You should of Demanded your cash back or reported him for selling faulty goods knowing it was faulty.

GTH · #9 (**permalink**) 01-11-2011, 12:09 PM

I`m glad you sorted the problem, and hope you`re satisfied with the shots you get. Sounds like that was one deceitful seller.

Geoff

Jonsfotos · #10 (**permalink**) 01-11-2011, 04:19 PM

The seller has shrugged his shoulders and walked away stating that he has taken 100,000 photos in three years with the lens on a 1ds without a problem

To me it appears the seller was having problems with it recently and decided it was time to offload it. I may be cynical but that is what it looks like to me. Anyway Keith, I am glad you have had it fixed and I hope you get some great shots with it.
all the best,
Jon