Since Pentax (and most other manufacturers) want to ensure the best image, sometimes they'll say certain lens and accessory combinations are "not recommended", as the results won't be up to their standards, although the pieces may fit together. For instance, they won't recommend stacking close-up filters to get high magnification.
Most teleconverters are optimized to work with long lenses, and don't work as well with short lenses, although you may be satisfied with the results. And yes, sometimes they physically don't fit certain lenses. Pat White - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
