Is there a 1.2 alpha lens?

Started Mar 3, 2013 | Discussions thread
kurja
Contributing MemberPosts: 764
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Re: Why?
In reply to Shield3, Mar 4, 2013

Shield3 wrote:

Sure it vignettes, but easily corrected in Lightroom. "Noticeable light loss" - yet the lens (F/1.4) is allowing 4 TIMES as much light IN as an F/2.8 lens. Sigh.

Vignetting is only a part of the problem. F1.4 is 4 times "faster" than F2.8 in terms of F stops, but how about T-stops? Is it actually allowing 4 times as much light? Likewise, the amount of light transmitted by the lens does not equal the amount of light recorded by the sensor - a smaller aperture allows a larger portion of it to be recorded, than a large aperture.
I'm not saying that F1.2 or 0.whatever  would be useless or anything though. Just that it's not quite as straightforward as you seem to think.

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