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Compras Nikon Bluetooth

Sigma's 70-300mm f4-f5.6 APO macro super lens has a compact apochromatic telezoom lens that incorporates two special low-dispersion glass elements in the front lens group with one special low-dispersion glass element in the rear lens group. The arrangement of the optics serves to minimize the chromatic aberration that can occur.

This telemacro zoom lens can achieve a magnification ratio of 1:2 (one-half life size) for macro and telephotography images at its 300mm focal length. As an accessory, you can add a 58mm achromatic close-up lens (not included), and get even closer focusing and reproduction ratios of 1:1 (life size) and still maintain excellent optical quality. The optical materials are made from lead-free and arsenic-free ecological glass. This model is dedicated to Nikon AF SLR cameras.

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1 Easy come, easy go.
I returned this lens the same day I received it. I found the macro function to be combersome, less than crisp, and with a miniscule depth of field. With no lock for the lens barrel, the lens extension continually slid forward with the slightest negative angle. And, once extended, the lens was awkwardly balanced and difficult to steady on my Novoflex head.

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2 Excellent Zoom with Great Macro Capability
It was between the very resonably priced 70-300 Nikkor and this one from Sigma. I chose this one, mainly on the basis of the macro capability, and glad I did. I've gotten some super honeybee shots, and frame-filling portraits. Resolution couldn't be better, fully equal to the Nikkor or any fixed focal length lens in this range (as far as I can judge.) Light and relatively short, it's convenient to carry. Pair this with a good short zoom, and you're set.

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I took a course in speed reading and was able to read War and Peace in

twenty minutes.



It's about Russia.

		-- Woody Allen





	An architect's first work is apt to be spare and clean.  He knows

he doesn't know what he's doing, so he does it carefully and with great

restraint.

	As he designs the first work, frill after frill and embellishment

after embellishment occur to him.  These get stored away to be used "next

time." Sooner or later the first system is finished, and the architect,

with firm confidence and a demonstrated mastery of that class of systems,

is ready to build a second system.

	This second is the most dangerous system a man ever designs.

When he does his third and later ones, his prior experiences will

confirm each other as to the general characteristics of such systems,

and their differences will identify those parts of his experience that

are particular and not generalizable.

	The general tendency is to over-design the second system, using

all the ideas and frills that were cautiously sidetracked on the first

one.  The result, as Ovid says, is a "big pile."

		-- Frederick Brooks, "The Mythical Man Month"