So, I just impusle-bought some super (super super) cheap extension tubes on ebay. After I clicked "commit to buy" I read the fine print: No electrical contacts, will no meter on lenses without aperture ring......whoops!!

So, what are my options? Through them in the bin (then I'll be out a whole $6-). Or can I play with them on my lenses? Just have to guess with the exposure?? Or will that wreck my lenses?

Thanks for the help!

(if it helps I have a D300s, 18-200mm, 35/1.8, 135/2)