What extenders fit htese lenses?

[hot-fuzz]

Im after a 1.4 extender for my Canon 400D but cant seem to work out which one i need.

I reckon i gotta get 2 extenders, one for each make, but anyway, here are the lenses :

Canon EF-S 60mm f/2.8 Macro USM Lens

and

Sigma 70-300mm f/4-5.6 APO DG Macro Lens

Ta for the help.

[jonnypb]

The Kenko 1.4x Teleplus Pro 300 DG should work. someone will correct me if i'm wrong

[richard plumb]

strangely the canon extenders don't work. They work on the 100mm macro but not the 60 (I checked as I have one)

As for the sigma, you might get a 1.4x teleconverter to work, but then you'll be at f8 at the long end, and your camera may not autofocus anymore.

[hot-fuzz]

Ta guys. IOm just looking to buy one to have a go and try something new.

Cheers for the help, will look into the Kenko one, seems quite cheap on Ebay (as long as its not a knock off), though its fairly cheap on OneStop.