Forum: Pentax SLR Lens Discussion
08-18-2009, 02:39 PM
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Got this lens, and started taking a few shots with it... alas, it seems soft in the corners. Perhaps a centering issue ?
At Paris CDG Airport (handheld):
The picture looks nice and sharp... excepted that top left corner.
Some tests I later made, using a tripod, at 12mm... (100% crops)
At f/4, center: nice and sharp, as expected from this lens
At f/4, left border: somewhat softer close to the border, but really good for a border
At f/4, top-left corner: VERY soft in the top left, the blur gets in very quickly and massively
The right side corners are also soft, although to a slightly lesser extent (the soft area is smaller)
At f/5.6, center: still very sharp, even somewhat sharper... as expected
At f/5.6, border: still good... but already somewhat worse than before at the very border ? Hard to tell...
At f/5.6, corner: still very blurry... and apparently even worse than at f/4
At f/8, center: no surprise, very sharp
At f/8, border: stopping down doesn't improve this area that much, it looks even worse the more it's stopped down
At f/8, corner: still at least as bad as before... if not even much worse :(
Of course, I won't exclude that my test isn't perfect - I was slightly misaligned with the wall, but at this focal length the depth of field is quite large... besides, I did multiple tries and moved the focusing ring, the results were the same. And as stopping down doesn't improve the blur, I'd guess it's not just due to being out-of-focus (which, anyway, wouldn't have made such a strong transition from sharpness to blur).
What are your thoughts about this ? I'm wondering if it's normal at 12mm and I just have unrealistic expectations, or I should send the lens back for servicing/exchange (2nd hand but still under warranty). Or could it be the camera itself ?
Looks like I'm condemned to shoot wide open, and not close more than 5.6 without some cropping...
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Forum: Pentax News and Rumors
08-12-2009, 02:43 PM
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For SLR, no... but as far as I've understood, they're still designing lenses for other types of businesses.
Now, would the core competency be MUCH different to go back to the SLR market ? I wouldn't think so, especially for a fixed focal of "average" length (no extreme wide or tele).
And on the other side... as far as optical engineering is concerned, we all know the A* 85/1.4 is great. If Samsung could get a license on the optical specs, and would just have worked on adding autofocus to it... then we'd have a real killer for sure.
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Forum: Pentax News and Rumors
08-12-2009, 02:14 PM
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Anyway, it genuinely seems to be a newly developped lens... whether it's a Samsung rebranding of a Pentax, or a genuine Samsung design, it's good news.
Even better news would be a genuine Schneider-Kreuznach design, exclusively made for the K mount and co-branded with Samsung (similar to what Zeiss is doing with Sony).
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Forum: Sold Items
08-11-2009, 12:21 PM
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... and fees are more in the 25% range in Europe, for information (VAT + actual customs fees). And even higher when that's shipped with UPS or FedEx, as they charge an extra for their import handling "services".
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Forum: Pentax Camera and Field Accessories
08-11-2009, 01:46 AM
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Alas, these parts are harder to find in Europe... anyone willing to buy an US set and ship it to me in France ?
Thanks...
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Forum: Sold Items
07-25-2009, 03:32 PM
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28mm on an APS-C corresponds to roughly a 42mm equivalent in full-frame, thus a good choice as standard lens, and wider and cheaper alternative to the 35/2.
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Forum: Sold Items
07-25-2009, 03:15 PM
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On the other side... it also depends on how the deal gets done. If the buyer pays everything first, and the item gets shipped through registered/express mail... how high would be the risks ?
But, for sure, it's also "simply human" to have more confidence in a forum's veteran than a newcomer (I should increase my psot count :p).
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Forum: Pentax DSLR Discussion
06-24-2009, 11:32 AM
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Sounds linke I need a thinner shim as my current one... trouble is, it's quite hard to get them from shops in France (they don't have spare parts).
I could use sandpaper on it, but considering (voidance of) warranty I'd prefer to use this on a spare one.
So, if someone has unused shims, and could ship them to France in a letter, please do contact me... I have no clue how much this costs, though. And a partial set of different thicknesses would interest me even more.
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