It was the circular portion of the description of the 85/1.2 II's aperture that was contributing it to it giving pleasing background blur (bokeh). That's what I've been trying to tell you.
"No, you're completely wrong. Circular apertures are precisely what give you "creamy OOF subjects" - to over simplify matters, a photo is composed of billions of points of light - circular apertures make these points circular, hence more creamy, hence more pleasing OOF areas. As apertures close down, the points become "rougher" giving a less pleasing image."
there's so much more to it than that. Have a read via google on the impact of correction for spherical aberration. The lenses with the best creamy bokeh typically have huge amounts of aberration and CA - mostly antiques. Modern lenses either aim for overcorrection (sharp, high microcontrast, but awful nisen bokeh) or neutral correction (slight CA, neutral bokeh), or mega-expensive asymmetric ground lenses that are undercorrected at large apertures and well-corrected at small apertures. None of this has anything to do with aperture shape.
The 85L has one of those expensive asymmetric elements, that's the main reason it has such excellent bokeh wide open. The aperture shape is just a little added bonus. This is easy to prove - when shot wide open, the aperture blades are fully retracted and have no impact on image quality. Yet every lens has a particular look to the bokeh wide open, so obviously there's a lot more to it than the aperture shape. Curved blades are just particularly easy to point out in marketing literature as an improvement over the last model, without have to write a giant essay on optics. Also, who ever complained that the 85L MkI with its straight blades has bad bokeh? Anyone? Bueller?
I get really sick of this uninformed debate sometimes. blind leading the blind.
Good bokeh certainly comes from a combination of factors, needless to say. But pleasing bokeh is the primary motivation having curved aperture blades, and they're designed to contribute that effect at wide apertures - that's all I was saying.
mh2000 wrote:
While not my personal favorite, the Super-Tak is a very well respected lens... the sample image shows how narrow the DOF can be and also shows some pleasing bokeh IMO... granted, it looks like a really forgiving background etc... and we'll have to see how it handles highlights and chunky textures etc... but I think it provides at least a hint that it will be a pleasing lens. It also shows why f1.2 isn't that important to me... DOF that narrow gets to look like tacky effect real fast.
I guess what stands out for me is the transition from whats in focus to what isn't. In other words, it doesn't appear to be as dramatic as what we see from the 85mm f/1.2, hence why it reminds me of my Tak. Who knows.. this image might be a really bad representation of this and I'll end up getting flamed for it.
I do agree though.. f/1.2 isn't that big a deal. And in truth, I think most of the time these fast lenses, with their blurring effect, are over used a lot of the time.
Yes, Sam, it is the primary motivation for curved aperture blades, but it mainly just seems to effect the shape distant highlights and not so much the nature of blurred objects. Most German lenses have both curved aperture blades and "other features" as well, whose purpose can only be to improve bokeh further.... why doesn't Canon do this? It can't cost that much to add a little notch or something to an existing design.
I figured with modern technology and a molded element this lense would be in the 800-1000 dollar range. Being that it's only 1/2-1/3 stop difference I just couldn't imagine it would be three times the price of the 1.4. I can only hope that it is more consistent in focusing that the 1.4. If I wait, it proves a better lense than the 1.4 and the price drops into this range I'll pick one up. Until then I'll wait to see what it really does.
I have one report from a person I trust regarding this lens, and he was not impressed. As he put it "It's sharpness falls off the edges at 1.2". Also has fairly severe vignetting issues wide open.
The possibly poor sharpness is borne out by the published MTF curves. Not any better than the 50/1.4, which isn't that good.
Re: bokeh. One of the main factors in producing 'good' bokeh is a certain amount of undercorrected spherical aberration. Once you work on 'fixing' this aberration, you either can go over to overcorrected spherical aberration under some conditions, in which case you will get ni-sen or 'bad' double line type bokeh, or, if you've really done a superb job in correcting this, as in some of the recent Leica-M lenses, you will have OK bokeh, but nothing like the superbly smooth rendition of such classics as the 4th generation 35/2 Summicron-M.
Round apertures only affect highlights, but if you have a fair number of highlights, that can make or break a picture. Just think of catadiotric lenses.
Henning wrote: I have one report from a person I trust regarding this lens, and he was not impressed. As he put it "It's sharpness falls off the edges at 1.2". Also has fairly severe vignetting issues wide open.
Henning
Well, Henning, that certainly does not sound good.
May I ask you if that person actually took pictures with the lens himself or he inspected someone else's images ?
Edited by handheld on Aug 26, 2006 at 01:17 AM GMT
Edited by handheld on Aug 26, 2006 at 01:17 AM GMT
Yeah, the EF 50 f/1.0L USM...
As far as the 50 f/1.2 is concerned, I think it will be a while before we find out what happens with it wide open. I really think (and hope) Canon should know better than to give us a 50 f/1.0 performance replay now.
hehe... nice LOTR analogies... good question about the 200L though... perhaps there should be another trinity for long range telephotos.... from what I have heard and seen (but unfortunately have not had the opportunity to try).. the 200L, 300 2.8 L IS, and
sivrajbm wrote:
I figured with modern technology and a molded element this lense would be in the 800-1000 dollar range. Being that it's only 1/2-1/3 stop difference I just couldn't imagine it would be three times the price of the 1.4. I can only hope that it is more consistent in focusing that the 1.4. If I wait, it proves a better lense than the 1.4 and the price drops into this range I'll pick one up. Until then I'll wait to see what it really does.
It's $1600.
That's over five times the price of the 50f1.4
The 135 f2 is only $900
Do you know what kind of excellent computer I can get for $1600 ?
A lot more complicated parts then whats in this CAD designed lens.
? It can't cost that much to add a little notch or something to an existing design.
