01-20-2011, 09:24 AM
[quote name='Brightcolours' timestamp='1295451179' post='5651']
CoC? Are you confusing two things? You can not see a CoC, the CoC is an imaginary entity to try and express how for instance print size and view distance influence perceived depth of field and sharpness.
[/quote]
No I'm not... By CoC I mean the spot consisting of non-perfect focussed points produced by the light cones coming through the lens. The brightness over this spot is homogenous if the lens does not suffer from spherical under- or over-correction. In that respect, I think the CoC has an effect of bokeh characteristics.
I never said that the shape of the aperture iris image has an effect on smoothness of the bokeh. I'm saying that the homogenous light disks result in smooth transitions in bokeh. I that context, I accept the idea that this defines the nature of the bokeh, and additionally the amount of the bokeh (which highly depends on the maximum aperture) together with this can tell a lot regarding the "creamyness" of it. OTOH, the characteristics of the bokeh depends on other things outside the lens barrel: picture format, distance to subject, brightness of subject back/foreground, shapes and patterns of the subject etc... So I think one should be very meticulous when comparing sample images.
In fact, checking the test shots in PZ again, I think that the bokeh of 200mm VR is as creamy as it can be for a that much fast lens (especially when stopped down a bit). I find the Voigtlaender APO Lanthar 90mm f/3.5 to have more creamy bokeh at it's maximum aperture, but the Nikon is still exceptional I think.
Serkan
CoC? Are you confusing two things? You can not see a CoC, the CoC is an imaginary entity to try and express how for instance print size and view distance influence perceived depth of field and sharpness.
[/quote]
No I'm not... By CoC I mean the spot consisting of non-perfect focussed points produced by the light cones coming through the lens. The brightness over this spot is homogenous if the lens does not suffer from spherical under- or over-correction. In that respect, I think the CoC has an effect of bokeh characteristics.
Quote:Also, the shape and homogenous quality of out of focus highlights have no one on one relation to the smoothness of bokeh. In fact, there are lenses that show very homogenous and round highlights, and yet have awful bokeh.
I never said that the shape of the aperture iris image has an effect on smoothness of the bokeh. I'm saying that the homogenous light disks result in smooth transitions in bokeh. I that context, I accept the idea that this defines the nature of the bokeh, and additionally the amount of the bokeh (which highly depends on the maximum aperture) together with this can tell a lot regarding the "creamyness" of it. OTOH, the characteristics of the bokeh depends on other things outside the lens barrel: picture format, distance to subject, brightness of subject back/foreground, shapes and patterns of the subject etc... So I think one should be very meticulous when comparing sample images.
In fact, checking the test shots in PZ again, I think that the bokeh of 200mm VR is as creamy as it can be for a that much fast lens (especially when stopped down a bit). I find the Voigtlaender APO Lanthar 90mm f/3.5 to have more creamy bokeh at it's maximum aperture, but the Nikon is still exceptional I think.
Serkan