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Minolta 50mm AF 1.4 - too dark at fully open?

Started Sep 9, 2017 | Discussions thread
lightdreamer New Member • Posts: 5
Re: Minolta 50mm AF 1.4 - too dark at fully open?

sybersitizen wrote:

Hans Weber wrote:

At wide apertures the lightrays are vignetted by the sensor itself due the flat angle they reach the pixels.

That's not the problem here. If it was the problem, it would not improve as the lens is stopped down.

Sorry but you are wrong here.

There are several reasons that lead to darker frames wide open.

https://en.wikipedia.org/wiki/Vignetting

First of all the manufacturers can call a lens f1.4 if it is not exactly 1.4 but for example 5% to 10% less. It is the same as for focal length were many (especially zoom-) lenses do not reach the real proclaimed values.

Second there is a natural cos4 rule that reduces light, but that leads to typical vignetting.

Third (look under the url) called "pixel vignetting" that is especially pronounced at f1.4 and wider, because the rays use a much wider Diameter to pass the lens.

BG

lightdreamer

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