Are you smarter than a 55-300? For this Bigmos, the answer is no.

Started Jul 4, 2014 | Discussions thread
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KentG Veteran Member • Posts: 4,316
Re: Are you smarter than a 55-300? For this Bigmos, the answer is no.

Bad examples. The Sony 70-400 (not 80-400) is somewhat soft above 200mm (both recent versions have the same optics). And the Pentax 60-250 while a very sharp lens thru the range is still superior between 80-200 and drops down at 250 a little especially in the corners. There is no 3x+ zoom that goes over 300mm in which the top end is sharper than the middle. Absolutely none. It is physics not design. The proper way to test a lens is to shoot a series of images at the same scale at each focal length, focusing manually. That takes the sensor out of the sharpness equation. Anything other than that you are testing both the lens and the sensor. That does not mean that a lens can't be acceptable sharp at the long end but for long lenses the test standard is intensionally varied by the focal length to allow for the physics.

Kent Gittings

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