Great explanations all! Thanks! The heard-mentality of a group as we learn in sociology, can be a strange thing indeed. Seeing someone recognize it in both "pop-culture" and the dynamics of a discussion forum abut photography and express it in a single sentence is an interesting and truthful treat. Nice!
I have one more question if I may. Why are we excluding close distance and macro shots?
I think they're mostly excluded because they don't represent the true nature of a lens' blur. Obviously they do represent how the lens performs at MFD, but most lenses produce very diffuse attractive blur at near focus. So one may see a great shot from a lens, buy it and find out that it has very harsh edgy, green ringed bokeh at medium distances and it's something like a portrait lens which is typically shot at medium distances... can be quite frustrating.
That's my understanding of the preference to exclude such shots at least.
thrice wrote:
I might be getting airy disk and circle of confusion confused
Yes you are, an Airy disc is a diffraction related term, which has nothing with bokeh to do. Circle of confusion or simply "blur disc" is what we're talking about.
Interestingly enough, the Airy disc is the CoC in the plane of focus, when we have a diffraction limited system! Which we have if we don't care about the resolution of the sensor.
This time I'm posting something which is not at all admirable, but actually very ugly. First photo is full frame downsized to webthumbnail size, which looks very good (almost any crap lens look good at webthumbnails). However the second picture contains crops from bokeh, which are very ugly due to bokeh CA. I'll have to say that I have never before seen this lens produce this ugly bokeh, typically I enjoy it's bokeh:
zombii wrote:
I've got a Makro Planar 100 too and I've never seen it do anything like that. Mine's a C/Y though. Not pretty.
yep, according to Apple Aperture I have taken over 3000 photos with this lens and I have never seen anything like this, not even close. This lens has bokeh CA problems but not on this scale typically. However also have to be taken into account that there is nothing in 975px wide picture indicating that bokeh is as ugly as it is, and the 100% crops would result VERY large print (if assuming 72dpi => picture would be 78"/198cm wide at this magnification).
Samuli Vahonen wrote:
yep, according to Apple Aperture I have taken over 3000 photos with this lens and I have never seen anything like this, not even close. This lens has bokeh CA problems but not on this scale typically. However also have to be taken into account that there is nothing in 975px wide picture indicating that bokeh is as ugly as it is, and the 100% crops would result VERY large print (if assuming 72dpi => picture would be 78"/198cm wide at this magnification).
I have an excellent copy of the Zuiko 90/2 Macro. In this post here in the CA thread from some time ago I showed what it can do...
Despite that ugly result I don't run into a lot of CA problems in real life shooting.
The defocus CA seen in your Zeiss image is no surprise, I think we have seen similar results earlier. I don't have anything to point at but samples here at FM Forums have made me think of the Zeiss 100/2 as similar to the Zuiko 90/2, maybe a little less CA than the Olympus but not stellar. That doesn't mean a lot of images are destroyed.
