Citation Envoyé par PhB
Hello, juste une question naive et double :
a) ? quoi correspond '250D' ou '500D' (rapport de grossissement ou qqch de ce genre?)
b) que donne une telle bonnette sur un 18-200 Sigma ?
Je n'ai jamais utilis? ce truc et je d?couvre m?me ? quoi ?a sert !
Voici la r?ponse !

These close-up attachments can be used with most EF lense to provide a shorter minimum focusing distance with no loss of light. The 250D/500D series incorporates double-element achromatic design for maximum optical performance while the 500 series features single-element construction for maximum economy. The 250D is optimized for lenses between 50-135mm, while the 500D works best with telephoto lense from 70-300mm. Manual focusing is recommended.