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About to dive in: Is X-E3 + 35mm f1.4 a good 'single prime' camera choice?

Started Mar 21, 2018 | Discussions thread
tokumeino Veteran Member • Posts: 3,175
Is the Mitakon 1 stop faster ?
1

georgehudetz wrote:

I had a similar experience. When I compared the shutter speeds of the Mitakon wide open vs the Fuji 35/1.4, again wide open, I was surprised how close they were. I never did a detailed comparison, and I have since sold the 1.4 so I can't do a comparison now, but I do recall reading other reports stating something similar to my findings.

I seem to recall it had something to do with how Fuji measures/characterizes maximum aperture.

This review (https://fstoppers.com/review/need-speed-fstoppers-reviews-mitakon-zhongyi-50mm-f095-lens-sony-fe-88817) states that

It is worth noting that while the f/0.95 aperture means lovely out-of-focus areas and hardcore subject isolation, that doesn't mean you're getting the equivalent of T/0.95 in terms of light transmission. In reality, you're getting closer to T/1.4.

BUT there is a very interesting post here : https://www.bhphotovideo.com/c/product/1226781-REG/mitakon_zhongyi_mtk35m95m2fx_speedmaster_35mm_f_0_95_mark.html comment "I stand corrected"

I previously gave this lens a 2 star review due to its price and apparent lack of exposure benefit. While it's true that the lens appears maybe .2-.3 stops brighter than the Fuji 35mm f1.4 (on an X-T2), I have come to realize that's not because of any deficiencies on the part of this lens. It has come to my attention that Fuji (and apparently many manufacturers) artificially increase the sensor gain when shooting at large apertures--even in RAW. This is due to diminishing returns when using large aperture lenses in combination with digital sensors. Something to do with pixel pitch and the angle of light coming through the lens.

In any case, what this means is that the camera does not artificially increase the exposure of images captured by the Mitakon since the lens has no chip in it to tell the camera aperture information. This means that images from the Mitakon show approximately 1-stop less grain than images from large aperture Fuji lenses. If your skeptical it's easy to test: Shoot a test frame at f1.4 with a Fuji lens. Then slightly disengage the lens until the camera registers f0 because it can't communicate with the lens. And take the test image again. You'll see an image ~1-stop darker.

Could someone with the 1.4 lens try what's in bold ? If it is true, then the Mitakon is indeed 1 stop faster. And there would be nothing to be proud about by Fuji.

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