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  1. #1
    Join Date
    Feb 2006
    Des Plaines, IL

    Talking Just to drive the "optical purists" amongst us nutz ...

    Just to drive the optical purists nutz ...

    I took the AF 200mm f/2.8 APO G HS lens and mounted to the Kenko 300 3x T/C ... mounted it on the a850 and then place it in the APS-C capture mode ... effectively making it ...

    well, let's do the math, boys and girls:

    200mm x 3x (T/C) x 1.5 (APS-C crop factor) = 900mm! Oh yeah!

    let's do the obligatory "light loss" calculation, too:

    f/2.8 x -3f/stops = f/2.8 ... f/4 ... f/5.6 ... f/8

    Hey, it still autofocuses! Hoohah!

    Obviously, it is not where near as sharp as ... hey, wait a minute, no one has a 900mm lens for the SONY mount. Cripes, you might get it with a 2x T/C and a 300mm f/2.8 APO G SSM in APS-C mode. Let's check the cost of that ... oh yeah ... $6150, for the 300mm f/2.8 lens alone! Hmmm, guess we will all just run out and pop for one of those, huh?

    Anyway ... for that long distance shot, you just cannot get closer to. Like Uncle Clyde coming down the slopes, in Vancouver, during the Olympics (2010).

    The image is pretty cool.

    200mm f/8

    Attachment 50559

    900mm f/8

    Attachment 50560

    I mean it is obviously not incredible zoom ... but the weight is incredibly light for it. The lens weight is 28 oz and the T/C is practically nothing @ 7 oz.

    The thing is, with optically zooming the image ... you still have all those pixels to blow the bad boy up either further! And there he is ... Uncle Clyde, shooshing down the slopes.
    Last edited by DonSchap; 11-19-2009 at 12:06 AM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

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