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Forum: Pentax Forums Giveaways
12-14-2014, 03:56 AM
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Best of luck to everyone, but most important: Merry Christmas!
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Forum: Pentax SLR Lens Discussion
12-07-2014, 03:02 AM
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Generally speaking, it is easy to make a good 50mm lens. Or maybe more correctly: It's easier than making wide-angles and zoom lenses ;)
Stopped down to, say, f 5.6 there won't be much difference between the sharpness of two randomly chosen 50mm lenses, but wide open there will be. Most lenses benefit from being stopped down a bit from fully open.
You may find this post somewhat interesting, where I compare 15 different lenses: https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/232618-simp...15-lenses.html |
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Forum: Pentax SLR Lens Discussion
07-27-2013, 12:11 AM
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Well, the window is deliberately part of the image - the idea was to test the lenses in a worse case scenario, and I often shoot against the light. But surely I agree - these lenses would perform much better in more normal lighting and with apertures in the 4 - 5.6 range.
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Forum: Pentax SLR Lens Discussion
07-26-2013, 01:12 PM
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It is because of the way the Tak 50/1.4 is constructed; a protruding rear. I've only experienced problems with the Nex adapters, but the lens works fine on Sony/Minolta SLRs and Pentax SLRs. Your best bet is to use the 50/1.4 on an SLR, or to get a Tak 55mm for your Nex...
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Forum: Pentax SLR Lens Discussion
07-26-2013, 12:42 PM
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Hi everyone!
Long time lurker, first time poster here :o
I've done a very simple test of 15 different lenses; I have no fetish for brick walls, but wanted to do a quick test of bokeh and chromatic aberration. To do so, I shot two images with every lens; one image fully open, and one image at a smaller aperture. For the 50mm lenses, the second shot was taken with an aperture of 2.8, but for the other lenses I chose just one step down. All images were taken using a Sony Nex-3, firmly held against a table (there may be small shifts in perspective, but nothing too serious for such a simple test). Focus were confirmed by x7 magnification on the LCD screen.
By the way; the Sony Nex user interface is driving me nuts, but I couldn't use my Pentax K-7 for this test, as I wanted to test Leica screwmount, Leica M, M42, Pentax-K and Nikon lenses on the same sensor...
Comments and observations are welcome! :)
Carl Zeiss C-Sonnar 50mm f1.5
Carl Zeiss C-Sonnar 50mm f2.8
Jupiter-8 50mm f2
Jupiter-8 50mm f2.8
Takumar 55mm/1.8 no 7339889 f1.8
Takumar 55mm/1.8 no 7339889 f2.8
Takumar 55mm/1.8 no 4718062 f1.8
Takumar 55mm/1.8 no 4718062 f2.8
Takumar 50mm/1.4 no 6626456 f1.4
Takumar 50mm/1.4 no 6626456 f2.8
Pentacon 50mm f1.8
Pentacon 50mm f2.8
Pentax-M 50mm/1.7 no 3354577 f1.7
Pentax-M 50mm/1.7 no 3354577 f2.8
Pentax-M 50mm/1.4 no 7142355 f1.4
Pentax-M 50mm/1.4 no 7142355 f2.8
Nikon-E 50mm/1.8 f1.8
Nikon-E 50mm/1.8 f2.8
Nikkor 50mm/2 f2
Nikkor 50mm/2 f2.8
Nikon-E 100mm/2.8 f2.8
Nikon-E 100mm/2.8 f4
Takumar 100mm/4 macro f4
Takumar 100mm/4 macro f5.6
Hanimar 135mm/2.8 f2.8
Hanimar 135mm/2.8 f4
Takumar 135mm/3.5 f3.5
Takumar 135mm/3.5 f5.6
Soligor 135mm/2.8 T2 preset f2.8
Soligor 135mm/2.8 T2 preset f5.6 (round aperture blades...)
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