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06-02-2008, 06:43 PM   #1
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Extreme bokeh test

Found a manual focus 28mm auto aperture lens to play with and it's quite promising. Here's a wide open aperture, extreme bokeh test I snapped on the way out of the office:



I've been trying to find a good quality manual focus wide angle lens to make available to folks on these forums. This may be the one as it has everything so far - auto aperture, sharpness, acceptable bokeh (further testing on the way), sturdy build (slightly heavy), low cost, some availability so nobody gets left out...

What do you folks think of the IQ, bokeh.
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06-02-2008, 06:59 PM   #2
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Bokeh looks good, IQ is just a tiny bit fuzzy. More testing is needed. The fuzz could just be the manual focus or too narrow DOF.

mike
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06-02-2008, 07:11 PM   #3
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bokeh looks a bit rough to me, although it might be just the subject
which lens is it?
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06-02-2008, 11:32 PM   #4
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Originally Posted by k100d View Post
bokeh looks a bit rough to me, although it might be just the subject
which lens is it?
it maybe JPEG artifacts... tough scenario to judge such a subject. Looks good to me.
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06-03-2008, 01:24 AM   #5
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My Super Takumar 28m f/3.5 occasionally gives me weird bokeh.
It ma have been due to the wind on the day though ... I have no idea though.

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06-03-2008, 09:06 AM   #6
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The brighter "rings" around the highlight circles are a bokeh problem. Makes the background highlights a bit busy...
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06-03-2008, 09:40 AM   #7
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Originally Posted by TourDeForce View Post


Maybe it is the contrasty background, but I didnt like this bokeh that much... can you try the same lens on a less aggressive background?
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06-03-2008, 06:35 PM   #8
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I agree with BBear, that bokeh is not very nice to my eye, but then again I don't think I would have used that composition for that picture if the flower was the main subject. The bright white sky doesn't add to the picture.
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06-03-2008, 07:31 PM   #9
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What lens?

Or are we to guess?
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06-04-2008, 07:23 PM   #10
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Originally Posted by KungPOW View Post
What lens?

Or are we to guess?
Testing continues. So far so good.

That was an agressive test to be sure. I actually expected the bokeh to be MUCH worse than that. Considering the test conditions the harshness of the bokeh is rather mild. You will note that some of the brighter light points on the right are actually filled in and taper, representing desirable bokeh. Under less extreme conditions, I've found the bokeh effects of this lens pleasing. Not ideal, but pleasing and complimentary to the scene rather than distracting. I'll post more samples soon.
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06-04-2008, 09:59 PM   #11
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Honestly what's the big deal in not letting us in on the lens used.
IMO the bokeh is horrid.
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06-05-2008, 05:57 PM   #12
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Originally Posted by creampuff View Post
Honestly what's the big deal in not letting us in on the lens used.
IMO the bokeh is horrid.
The big deal is that I'm hunting for a lens to sell. I don't want to let the cat out of the bag and lose any sales.

Turns out I agree with you, the bokeh is not good - mostly. In this case because the situation is rather extreme. Other situations the typical bokeh is not bad.

The lens has other problems and I will not be selling them. The aperture is a bit sticky no matter what I do. I even dis-assembled the lens to lube it up, thinking I got a bad sample. After looking into it, the design is prone to failure. Lube was of no help as expected.

FYI, it is this lens: Vivitar 28mm 1:2.8 Wide Angle Lens - eBay (item 7603328835 end time Jun-10-08 09:54:37 PDT)

Late model Vivitar made in Korea, likely by Samyang. Optical resolution improves away from wide open, but still not up to par.
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06-06-2008, 12:58 AM   #13
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The bokeh isn't "that" bad for a 28mm lens, and I'm assuming it's wide open. 50mm's can tend to have swirly bokeh, depending on the design.

Stop down to f/4 or so and the bokeh should improve by a lot.





Oh and by the way:
Originally Posted by TourDeForce View Post
The big deal is that I'm hunting for a lens to sell. I don't want to let the cat out of the bag and lose any sales.
Lame.
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