Sigma 70-200 Mk2 + 2x teleconverter

[freeman3030]

Hi,
I've just bought a Sigma 70-200mm Mk2 on eBay and after I put my bid on I properly re-read the item specification and I found out that the seller is including a Sigma 2x teleconverter in the sale! Fortunately for me I won because I feel like I've almost got the 2x converter for free as I was prepared to pay the price just for the lens.
Anyway I guess thats neither here nor there (but perhaps I could learn from this to properly read the item description! You don't always have something to gain.)

Anyway, I just looked into the teleconverter (as at the time I hadn't considered the converter) and have a question about it:
Will I still be able to autofocus when using the converter?
I have a Nikon D3100 if that affects anything.

Thanks,
James

 

[HoppyUK]

Assuming the 70-200mm lens is f/2.8, then yes it will AF with the 2x telecon. It will become 140-400mm f/5.6.

 

[freeman3030]

Yes it is the 70-200mm f/2.8 HSM blah blah whatever the rest of the title is!