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Title: Canon 25mm Extension Tube. Post by: Leong on August 17, 2008, 09:26:38 PM Mr.Bob,
Could you advice me on which proper lens / lenses to use with the above mentioned subject. i have got the Canon 40D with me and the extension tube. Many thanks... Title: Re: Canon 25mm Extension Tube. Post by: Bob Atkins on August 21, 2008, 11:36:30 AM You can put the Canon 25mm extension tube on any lens. The original version will accept an EF mount lens, but not EF-S lenses. The newer (current) Mark II version will accept EF-S lenses too.
An extension tube reduces the minimum focus distance of a lens, and the effect is greatest with the shortest focal length lenses. Though it contains no optics, using an extension tube can affect image quality and field flatness when used for closeup work with shoter focal length lenses (say 35 mm or shorter). When used with longer focal lengths (say over 100mm), there's very little effect on image quality. See http://www.bobatkins.com/photography/eosfaq/closeup2.htm |