I've got the Sigma 50mm Macro lens for my crop camera, it works well and offers great bang for the buck. I wouldn't mind being able to go beyond 1:1. An acquaintance has a Canon extension tube EF25 II for sale for $75. With the short working length of my 50mm, would I be able to use this tube, or would it result in my having to set the subject on the lens to get it in focus?
Eventually I'd like to go with a 180 Macro lens, but it's not in the finances this year.