Which zoom Lens

Discussion of lenses, brand or independent, uses and merits
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ruthless
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Re: Which zoom Lens

Unread post by ruthless »

OK I am a little confused, the 70-300 g SSM will produce the same size image at 3000 as the beercan at 210?

I have the a700, so would the 70-300ssm be better for me than the 70-400 ssm? I am all about sdaving some cash, if you had a $1000 US budget what current new lens (300 or longer) would you choose for shooting widlife.
Cory "ruthless" Routh
David Kilpatrick
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Re: Which zoom Lens

Unread post by David Kilpatrick »

At 1.1m - not at infinity. It is down to the way they focus. The 70-210mm focuses using front group extension. With this design, the effect is to lengthen apparent focal length, so that it achieves 0.25X life size at 1.1m - a true focal length of 1.1/5, or 220mm. The 70-300mm SSM uses internal rear group focusing, and focuses to 1.2m, achieving exactly the same 0.25X, despite being at '300mm'. The real focal length is actually around 240mm after the internal group doing the focusing has moved.

But, at infinity, the 300mm of course produced 1.5X greater magnification than the 210mm. Between minimum focus and 'portrait distance' the trade-off is probably visible with the 70-300mm SSM, but beyond that, the extra focal length is not compromised.

David
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bakubo
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Re: Which zoom Lens

Unread post by bakubo »

ruthless wrote:I have the a700, so would the 70-300ssm be better for me than the 70-400 ssm? I am all about sdaving some cash, if you had a $1000 US budget what current new lens (300 or longer) would you choose for shooting widlife.
I haven't used it, but you might look into the Tamron 200-500mm also. No SSM, of course, but it sells at Amazon.com for a bit over $900.

http://forums.dpreview.com/forums/read. ... e=31517198
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ruthless
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Re: Which zoom Lens

Unread post by ruthless »

I actually rented that Tammy from apha mount rentals. It was apretty nice camera and at that time i was still unfamilular wiht my a700. migh be worth another look.

Henry, Ill be in your neighbobhood the last two weeks of August. Visiting my sister-in-law at sunset beach. Might have to hit you up for some good photog ops, and fishing spots. :mrgreen:
Cory "ruthless" Routh
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