Why Fuss Over Lens Bokeh?

BC wrote:

Might have to revise my guess.


It would be nice if you left prev. post context in place.

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Hi Mark:
Thanks for the hint. I use google almost always for looking at usenet,
and it seems to keep getting worse in terms of functionality. None of
these problems used to happen to me.

Brian
www.caldwellphotographic.com

Paul Furman wrote:

If you could shoot the same scene at the same f-stop with the 1.8 & the
1.2 that would be very helpful!

Okay, that was interesting. I don't normally do lens tests.

Both lenses at their max apertu

http://www.exit109.com/~jeremy/50-1....-schmuckle.jpg
http://www.exit109.com/~jeremy/50-1....-schmuckle.jpg

Both lenses at f/2:

http://www.exit109.com/~jeremy/50-1.2-f2-schmuckle.jpg
http://www.exit109.com/~jeremy/50-1.8-f2-schmuckle.jpg

No real attempt to make them look like nice pictures.

My conclusion: wide open, the 50/1.2 is a contender, though not very sharp;
some sharpening would be necessary and the lower contrast could be dealt
with as well. The schmuckle, while not great, is not anything I'd have a
problem with, and looks a bit better. At f/2, the 1.8 wins handily. That
out of focus greenish light in the low center of the picture is pretty
nasty with the 1.2 at f/2, for example, taking on the aperture shape.

I honestly think this was the first time I stopped down the 50/1.2 as far
as f/2.

I'm missing the 24mm-70mm range (except the 28-200) so would like a good
bokemeister for that. I might consider an 85 to 135mm too if it really
offers something special.

The Nikon 85/1.4, 105/2, and 135/2 are all schmucklemeisters. Those last
two, with the defocus control, take some experimentation to get the hang
of; I have the 105, and it's a really, really nice lens, but I had to play
with it a bit and I found that on mine, the "neutral" point for the defocus
control is actually 2F rather than the midpoint. Evidently, it's common,
and some people find their particular copies have a different neutral
setting.

--
Jeremy |

"My conclusion: wide open, the 50/1.2 is a contender, though not very
sharp;
some sharpening would be necessary and the lower contrast could be
dealt
with as well. The schmuckle, while not great, is not anything I'd have
a
problem with, and looks a bit better. At f/2, the 1.8 wins handily.
That
out of focus greenish light in the low center of the picture is pretty
nasty with the 1.2 at f/2, for example, taking on the aperture shape. "

The out of focus greenish light also takes on the aperture shape in the
50/1.8 shot at f/2, its just that the aperture shapes for the two
lenses at f/2 are different.

The dim amber-colored highlight to the right of the bright green one is
also interesting. In the 50/1.8 at 1.8 it shows a diffuse bright
center and a bright outer ring. At f/2 the outer ring is less
pronounced. Had you tried a shot at f/2.8 the outer ring would have
dimmed considerably more, or disappeared altogether, leaving you with
very nice bokeh except for aperture shape effects.

Also, it seems to me that the 50/1.2 at f/2 has better background bokeh
than the 50/1.8 at f/2. The amber highlight in the 50/1.2 @ f/2 shot
has almost no bright ring effect at all, just an aperture shape
problem. The portion of brick wall at the extreme left is less smooth
in the 50/1.8 @ f/2 shot, as is the vertical bars in the left-most
doorway.

Brian
www.caldwellphotographic.com

BC wrote:

Also, it seems to me that the 50/1.2 at f/2 has better background bokeh
than the 50/1.8 at f/2. The amber highlight in the 50/1.2 @ f/2 shot
has almost no bright ring effect at all, just an aperture shape
problem. The portion of brick wall at the extreme left is less smooth
in the 50/1.8 @ f/2 shot, as is the vertical bars in the left-most
doorway.

Interesting points. The shape of the highlights had me ignoring the
other stuff. Now that I look with what you've pointed out in mind,
the rest of the look does seem better. Now, who says aperture shape
doesn't play a role?

--
Jeremy |

BC wrote:

The dim amber-colored highlight to the right of the bright green one is
also interesting. In the 50/1.8 at 1.8 it shows a diffuse bright
center and a bright outer ring. At f/2 the outer ring is less
pronounced. Had you tried a shot at f/2.8 the outer ring would have
dimmed considerably more, or disappeared altogether, leaving you with
very nice bokeh except for aperture shape effects.

Also, it seems to me that the 50/1.2 at f/2 has better background bokeh
than the 50/1.8 at f/2. The amber highlight in the 50/1.2 @ f/2 shot
has almost no bright ring effect at all, just an aperture shape
problem. The portion of brick wall at the extreme left is less smooth
in the 50/1.8 @ f/2 shot, as is the vertical bars in the left-most
doorway.

Agreed, that amber light puts the 1.2 ahead in both cases.

PS I started a thread in alt.photography and rec.photo.35mm.equipt & got
the recommendation for a 45mm f/2.8 P which is manual focus but chipped
for metering and specifically designed for good OOF as well as super
sharp. It's a tiny thing only 1/2-inch thick, about $350.

Here's a test of a couple of my lenses showing how different the OOF can be:
http://www.edgehill.net/1/?SC=go.php&DIR=Misc/photography/bokeh/compare

If you really want a headache, here's a bunch of tests:
http://www.bokeh.de/en/bokeh_images.php

--
Paul Furman
http://www.edgehill.net/1
san francisco native plants