Questions regarding Extension Tubes

[Jelster]

I have, for some time, fancied doing a bit of macro, but didn't want to make a major investment until I've dipped my toe in the water, so to speak. With that, extension tubes come to mind but I have a couple of questions.

1) I know it's good practice to manually focus while in macro, but do the 3rd party makes of tubes provide the AF function ?

2) If I was to get the Canon EF25 MkII tube, would I be able to put an EF-S lens on my 6D (I'm thinking of my 17-55 EF-S f2.8)

3) Is there a 3rd party make that I should be looking at ?

My idea is to use the tube(s) with either my 50mm or 85mm f1.8 lenses, possibly my 24-105, and as above, the 17-55.

Thanks for any advice.
Steve

 

[arclight]

Kenko is a good 3rd party make. They have the necessary electrical connections to permit the lens to auto focus etc.

I'll duck the Canon question. I am on the dark side

 

[Nikon_Nick]

Dark side here also, but you could also look at a reversing ring and use your '50' backwards