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08-05-2010, 09:23 AM   #1
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Is this FA 31mm a keeper?

Just purchased a new Pentax 31mm from Adorama. Could someone help me with the brick wall test? I have not done this before. I have linked to the original size photos; all JPEGS. I also have the RAW version if needed.

All shot with a K-7 on a tripod with shake reduction turned off. Some are auto focus and some manual. What do you think? Thanks! Edmund

F1.8 ISO200

http://farm5.static.flickr.com/4117/4861551465_635dd2af82_o.jpg


F2.8 ISO200

http://farm5.static.flickr.com/4118/4862169234_37641149bd_o.jpg

F5.0 ISO 400

http://farm5.static.flickr.com/4075/4861515273_fbaac0e63a_o.jpg

F7.1 ISO400

http://farm5.static.flickr.com/4119/4862139632_fe8653a7b5_o.jpg

F22 ISO400

http://farm5.static.flickr.com/4098/4861525979_29c889b7f0_o.jpg

08-05-2010, 09:42 AM   #2
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Who cares about brick walls? Get out and take some real photos!
08-05-2010, 09:52 AM   #3
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If that's supposed to be a brick wall, then yes!

Seriously though, any specific concern about the lens that compelled you to do this test?

Looks very sharp by f/2.8 as it should--perhaps a bit less contrast / definition in the bottom half, but that could be lighting.

By f/22, nothing will look good, so no worries there.
08-05-2010, 09:59 AM   #4
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I have heard of this test as a way to judge the sharpness from center to the edges.

08-05-2010, 10:02 AM   #5
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QuoteOriginally posted by Edmund Quote
I have heard of this test as a way to judge the sharpness from center to the edges.
It's a keeper. Go shoot. Have fun.
08-05-2010, 10:05 AM   #6
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QuoteOriginally posted by deadwolfbones Quote
Who cares about brick walls? Get out and take some real photos!
x1 bazillion.
08-05-2010, 10:19 AM   #7
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QuoteOriginally posted by Edmund Quote
I have heard of this test as a way to judge the sharpness from center to the edges.
All images will be softer to some degree near the corners, because....

assuming you are focusing on the center of the image at X distance, the corners will be X-plus something distance.
08-05-2010, 11:02 AM   #8
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QuoteQuote:
I have heard of this test as a way to judge the sharpness from center to the edges.
I have heard many things...

Brick wall tests, if you have no reason to suspect anything amiss, are useless. they serve to make you worry about your lens, instead of using it to take pictures.

They are useful if your real life pictures bother you, and you want to evaluate a problem. Otherwise, brick wall tests hurt your eyes and serve no purposes.

08-05-2010, 11:38 AM   #9
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Hm.... I agree with what other said, go out and shot (not walls)!

enjoy your new toy.
08-05-2010, 12:17 PM   #10
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Lens is like an extension of the eye. We only realize the physical property when we go see an ophthalmologist for checkups, but no one talk about them daily when we are busy seeing and observing (what's the f number of your left eye btw?). That's what I believe a lens should be, to be used to observe the world, not to be used for paper specs.

So go out and enjoy the world through your lens.
08-05-2010, 12:27 PM   #11
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Send it to me for evaluation. It shouldn't take me any more than 6 weeks.

Edit: BTW, tell whoever owns that building that some of their bricks are crooked.
08-05-2010, 02:42 PM   #12
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Bricks???

I don't get this??? Why? Just use the lens! BRICKS with a 1000+ EURO Lens!!!

This was taken with the 31 Ltd and the K20D..
Attached Images
 
08-05-2010, 02:46 PM   #13
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I don't agree with the rest of them. It looks pretty bad to me. I'll take it off your hands so it isn't a total loss. How about 50 bucks and a six pack of bud.

I finally got out of the brick wall tests and took more pictures. They magically got better and sharper over time. I guess lenses ripen.
08-05-2010, 02:55 PM   #14
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QuoteOriginally posted by benjikan Quote
I don't get this??? Why? Just use the lens! BRICKS with a 1000+ EURO Lens!!!

This was taken with the 31 Ltd and the K20D..
I dunno, Benji... looks pretty soft to me.

08-05-2010, 03:25 PM   #15
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QuoteOriginally posted by VaughnA Quote
I don't agree with the rest of them. It looks pretty bad to me. I'll take it off your hands so it isn't a total loss. How about 50 bucks and a six pack of bud.

I finally got out of the brick wall tests and took more pictures. They magically got better and sharper over time. I guess lenses ripen.
6 Pack of BUDDDDDD!!!!!!!!!!

Are you nuts....a 6 Pack...I'll give you my 31,40,43,50,70 and girlfriend for a 6 Pack of BUD!!!! Geeeezzzz what is happening to this world of ours. R U out of your friggin mind or what???
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