I just purchased a 2x teleconverter for my Minolta Maxxum I is for use with my 300m zoom lenses. I cannot get a picture in focus when I am looking through the lense no matter how far away I am away from the subject. I have tried both manual and auto focus. What am I doing wrong?

-- jackie straub (jackie.straub@fieldcontainer.com), May 30, 2001

Answers

2x converter, plus xx-300mm f5.6 consumer grade zoom lense = 600mm f11. An f11 lense will not autofocus on any camera. An f11 / 600mm lens must be impossibly difficult to focus manually.

Strap your rig onto a tripod, and try to focus manually. Take some test shots while your at it. You may find that this approach may not be practical for the type of application that you bought the 2x for, and in that case, return it and get your money back.

I would not be surprised if the resulting test shots are less than satisfactory.

-- Ken Katz (socks@bestweb.net), May 30, 2001.

The Minolta AF APO teleconverters will only function with certain dedicated Minolta APO prime lenses. They will not function on any zoom lens. Assuming you are not talking about one of those TCs.... teleconverters are made primarily to be used on good prime lenses. A superior 1.4X teleconverter will produce pretty good results when used with a very good zoom, for example the high quality 80-200mm f2.8 type zooms. Suprisingly good results can even be achieved in some cases when coupling a superior 2X teleconverter with a superior zoom, if excellent technique is utilized and the image is not intended for great enlargement. A mediocre 2X teleconverter coupled with a mediocre 300mm zoom should produce rather mediocre results, I'm afraid and the viewfinder image would be about f11 and very dark. It would be difficult at best to focus and you would certainly not have autofocus capability.

-- George Rhodes (betsy@colormewell.com), May 30, 2001.