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RF 50mm f1.8 stm review.

Started Dec 29, 2020 | Discussions thread
Karl_Guttag Senior Member • Posts: 1,883
Flange distance and Sensor Illumination Angles

sobrien wrote:

Swerky wrote:

The digital picture have finished the review of the RF 50mm 1.8. Wasn't the larger mount diameter supposed to bring, among other things, less vignette to the image?

The RF mount diameter isn’t larger than the EF one.

The RF flange distance is shorter, though, which I understand means light hitting the sensor at more oblique angles which I believe could contribute to the greater vignetting, though I stand to be corrected on that by someone who understands this stuff better than I do.

Perhaps I'm wrong.
https://www.the-digital-picture.com/Reviews/Lens-Vignetting-Test-Results.aspx?FLI=0&API=0&FLIComp=0&APIComp=0&Lens=1528&Camera=1508&LensComp=989

It is a very interesting question as to how much the illumination angle of the sensor affects the vignetting. A simple sensor illuminated at an oblique angle would be expected to have vignetting effects in the corners, Things like microlenses on the sensor would help but not eliminate the issue.

I'm don't know what The Digital Picture is doing to test the Lens. It looks like they are using some kind of lab equipment and not just taking pictures with the camera for the vignetting image.

It would be interesting if some cameras/sensors exhibit more or less vignetting with the same lens.

 Karl_Guttag's gear list:Karl_Guttag's gear list
Canon EOS R5 Canon RF 15-35mm F2.8L IS USM Canon RF 24-70mm F2.8L IS USM Canon RF 70-200mm F2.8L IS USM Canon RF 24-240mm F4-6.3 +14 more
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