Diffraction??

[Mr.Nikon]

hello everyone I found a Youtube video about diffraction. He believes that diffraction is dependent on the quality of your lens. Diffraction depends only on your used aperture and is not dependent on whether your lens is originally f4 or f2.8. Diffraction at f/11 is the same for an f4 and an f2.8 lens. Is that not correct??. Link below:

View: https://www.youtube.com/watch?v=U9CRXBil56c


Best regards
Mr.Nikon

 

[woof woof]

It's not something I generally worry about but if I was to think about the technical aspects of it I think I'd believe that it depends on the aperture but also in digital photography the resolution of the senor, the size of the pixels and the airy disk... and all that. I suppose the lens will matter as there'll be differences in how the light is focussed and sharpness from one lens to another but I'm only guessing or maybe the effect of a less good lens only looks like diffraction but isn't.

Oh dear. This is why I tend not to worry about it

 

[sk66]

Diffraction at f/11 is the same for an f4 and an f2.8 lens. Is that not correct??

Yes, but the size of the point blur/airy disk is not only dictated by diffraction; it is also contributed to by optical errors.

A perfectly sharp "diffraction limited" lens would be sharpest at it's widest aperture. But most (all?) lenses are not diffraction limited because spherical aberrations are creating more blur than diffraction is at wider apertures. So stopping down is a tradeoff between the two causes of blur, in order to find the aperture with the lowest total blur.

I didn't watch the video.