I bought the Pentax 31mm f1.8 because I wanted a sharp lens with good bokeh to go with my Pentax K5.
Based on the review (and pictures) here and other places, i expected better results at 1.8 than the picture at this link: http://chals.zenfolio.com/p296791352/h133dcd4?#h133dcd4
The result are always like this, far away or close.
Can someone here who know the lens tell me if there is something wrong with my copy.
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What are you showing us in the linked image?
The image does not contain exif-data or description, it is by far to small
to say much about it, you don't tell about the circumstances under which
you took those images ... this seems to a clear case for my cristal ball ...
but is that the type of answer you are looking for?
the picture is a dump from LR at 200% . Aperture is 1.8 and 2.8 shutterspeed is 1/2000 for the 1,8 shot. i think it is possible to judge the pictures, espesially if you have seen a sharp/unsharp 31mm ltd before
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Well, the obvious first:
The f-2.8-image is better than the f-1.8-image ... this is something very common ...
use a lens wide open, and use it stopped down a bit, and image quality increase.
What I don't like, is (besides reduced contrast which would be ok) the way it behaves
on the contrasty white edge ... this seems to me as if a cheap UV filter has been on the
lens when taking this image. I mean ... it is clear that this shot is for test purposes ... since
there is nothing in this image requiring f/1.8 ... nevertheless, one wouldn't expect this in the
image center.
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[quote name='chals' timestamp='1311537795' post='10218']
the picture is a dump from LR at 200% . Aperture is 1.8 and 2.8 shutterspeed is 1/2000 for the 1,8 shot. i think it is possible to judge the pictures, espesially if you have seen a sharp/unsharp 31mm ltd before
[/quote]
Looking at this odd halo effect I suspect a centering issue.
Please check ...
http://forum.photozone.de/index.php?/topic/830-do-it-yourself-centering-sanity-check/page__p__7409__hl__decentered__fromsearch__1#entry7409
thank you very much for the tip, I will perform this test as soon as I get back from holiday. When using a Pentax K5 with tripod and AF focusing; the result will be unsymetrical and somewaht blurres images on edges(not the eges of the frame) of the target object. Probably a good idea to test the 18-135 zoom at 31mm focal length too?
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[quote name='chals' timestamp='1311582322' post='10223']
thank you very much for the tip, I will perform this test as soon as I get back from holiday. When using a Pentax K5 with tripod and AF focusing; the result will be unsymetrical and somewaht blurres images on edges(not the eges of the frame) of the target object. Probably a good idea to test the 18-135 zoom at 31mm focal length too?
[/quote]
In the dead center the edges should be perfectly symmetrical regardless of the lens.
You can, of course, check the 18-135 but this is independent from the 31 in any case (unless we are talking about a camera defect).
Remember to switch off SR for the procedure.
