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PostPosted: Sun Sep 21, 2008 1:49 pm 
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Bonjour,

A 1.4x teleconverter has been announced for Pentax SDM lenses.

Image

But, how does a teleconverter work :?: What are the consequences on image quality, aperture, ... :?:

Gordon and/or Bob, Could you please explain us :?:

Thanks :)

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PostPosted: Mon Sep 22, 2008 5:43 pm 
Why explain it when others have done it before.

Here Wikipedia's article.

And here the 2nd reference from that article.

Hopefully they will tell you all you want to know.

Ben
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PostPosted: Mon Sep 22, 2008 6:37 pm 
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Following on from that Wiki article, as I understand it a teleconverter/extender not only magnifies any optical defects of the lens it is coupled to but it will introduce its own defects. If you are lucky you might find a review of your desired combination but if not then bear in mind that f the main lens isn't really sharp on it's own then you may see little benefit adding a teleconverter over and above what you could obtain by "digitally zooming". I should probably add a health warning to the above and state I've never owned a teleconverter/extender so this is just my take based on what I've read elsewhere. :wink:

Bob.

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PostPosted: Mon Sep 22, 2008 7:07 pm 
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Bonsoir Can-I-Am and Bob,

Thank you for the links and the answers.

I've already read the wikipedia article which is fine from a technical point of view (no pun intended :) ).

The magnification of the optical defects of the lens the converter is attached to, is a real issue. I hope the Pentax DA* lenses to be good enough to support a teleconverter without significant loss of image quality.

But wait and see :!:

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