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So finally ... the new Leica DG 100-400mm f/4-6.3 OIS
#38
That is not quite true, Wim. Sensors very clearly get hit by diffraction. Any test shows that, as does the underlying physics predict that. Luminous Landscape used to have a very good and thorough article about the impact of diffraction and the maximum MP one could get for different formats with different aperture sizes, but it seems to have disappeared for non-members.

 

It (diffraction softening) is easily seen in the PZ tests for resolution, and even more clear in the lens tip tests (because lens tip does not sharpen results.

Example from PZ 16mp MFT:

http://www.opticallimits.com/m43/830-oly75f18?start=1

From f4 on, we see the resolution figures gradually drop. This is due to diffraction alone.

 

Another example, on the 12mp E-PL1, from lenstip:

http://www.lenstip.com/477.4-Lens_review...ution.html

[Image: 162810_roz.png]

We clearly see a drop in measured resolution from f4 onwards. Due to diffraction.

 

A quick test shows this clearly in images too, Macro lens wide open, at f8 and f16 at macro distances on EOS 6D:[ATTACHMENT NOT FOUND]

 

For e-line (a green) wavelength (546.1mm), fro f4 the max resolution is 375 lines/mm. For f5.6, down to 268. For f8, 188 (source: Nikon industrial lenses). That is for a single shortish wavelength. Longer wave lengths (which are part of normal visible light) produce much lower resolutions due to diffraction.

 

http://physics.stackexchange.com/questio...iffraction

 

 

  


Messages In This Thread
So finally ... the new Leica DG 100-400mm f/4-6.3 OIS - by Scythels - 01-05-2016, 09:06 PM
So finally ... the new Leica DG 100-400mm f/4-6.3 OIS - by Scythels - 01-05-2016, 09:57 PM
So finally ... the new Leica DG 100-400mm f/4-6.3 OIS - by Scythels - 01-05-2016, 10:48 PM
So finally ... the new Leica DG 100-400mm f/4-6.3 OIS - by Scythels - 01-06-2016, 02:35 PM
So finally ... the new Leica DG 100-400mm f/4-6.3 OIS - by Lassoni - 05-12-2016, 11:46 PM
So finally ... the new Leica DG 100-400mm f/4-6.3 OIS - by Brightcolours - 06-19-2016, 12:14 PM

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