I just got a used Lee Foundation Kit and I need to buy adapter rings for my lenses. I'm primarily using my 18-135 for landscape and I'm wondering if on a crop sensor I would need to buy the wide angle version of the adapter ring or if I can get away with the much cheaper standard version?
I didn't see a "filters" section in Gear Talk so I figured I'd ask the ones that likely use this type of gear the most, the landscape section 
Thanks for any help!

