01-03-2011, 04:13 PM
[quote name='mst' timestamp='1294061346' post='5317']
Since the aperture of the lens has been successfully calibrated by Tamron Europe, all affected lab tests were redone and graphs updated.
The verdict remains unchanged, however. And this is surprisingly also true for the way too good resolution fully stopped down.
http://www.opticallimits.com/nikon--nikk...0_20_nikon
-- Markus
[/quote]
Not all lenses show exactly the same amount of softening due to diffraction at the same f-stops, I think that has to do with the position of the aperture (not sure). So in theory, it might just be that this Tamron design is just exceptionally good in this area.
However, we have to leave that idea when we look at how the same lens performs on another camera:
Nikon (D200):
![[Image: mtf.png]](http://www.opticallimits.com/images/8Reviews/lenses/tamron_60_20_nikon/mtf.png)
Canon (EOS 50D):
![[Image: mtf.png]](http://www.opticallimits.com/images/8Reviews/lenses/tamron_60_2_50d/mtf.png)
We can see here that it is NOT the optical design... so it must be that the aperture is not correct. Have you checked exposure durations?
Since the aperture of the lens has been successfully calibrated by Tamron Europe, all affected lab tests were redone and graphs updated.
The verdict remains unchanged, however. And this is surprisingly also true for the way too good resolution fully stopped down.
http://www.opticallimits.com/nikon--nikk...0_20_nikon
-- Markus
[/quote]
Not all lenses show exactly the same amount of softening due to diffraction at the same f-stops, I think that has to do with the position of the aperture (not sure). So in theory, it might just be that this Tamron design is just exceptionally good in this area.
However, we have to leave that idea when we look at how the same lens performs on another camera:
Nikon (D200):
Canon (EOS 50D):
We can see here that it is NOT the optical design... so it must be that the aperture is not correct. Have you checked exposure durations?