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03-02-2011, 12:52 PM   #16
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QuoteOriginally posted by Vylen Quote
Although I should be sleeping soon since I have work tomorrow, I still took some quick ad-hoc distortion test photos with my copy of the lens using the venetian blinds at home.

Here are the photos at various focal lengths.
Thanks for the examples! Good job!

Seems there is quite alot of distortion at 18mm,

But... is that alot of invard distortion at 48mm and 60mm???
Or is it the blinds?

03-02-2011, 02:28 PM   #17
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No, the blinds are as straight as can be - the horizontal panes anyway - you can verify that based on the window itself and the top of the fence.. no guarantee the stringy parts that hold them together are perfectly straight (and perpendicular to the panes/floor).

But, for checking the vertical for distortion, look behind the blinds and try use the fence as a guide

But yea, there's pretty much distortion across all focal lengths, but at least it would take some nitpicking at the bigger lengths in "normal" situations (at least, i think so)
03-02-2011, 07:07 PM   #18
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Great pics for checking distortion.. and WOW thats fairly significant distortion.. Barrel at 18mm and already pincushion at 31mm? I wonder where its sweet spot is between 18-31mm for zero distortion. Hmm that 100 Macro WR is looking better and better.. Disappointing for a $600+ lens to show such distortion across its entire focal range. I wonder how much the K-5's option for Distortion Correction can negate this lenses shortcomings.\
To me "Reasonable" would mean pincushion is not evident until 90mm-135mm, not starting at 31mm or sooner.
03-02-2011, 08:16 PM   #19
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I suppose I could try find the sweet spot for zero distortion.. but that would take a while...

03-02-2011, 11:01 PM   #20
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Yeah, hard to tell through the viewfinder or small LCD screens.. I'm looking in to how much distortion compensation the K-5 can do... could be a work-around for the lens.
03-02-2011, 11:56 PM   #21
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QuoteOriginally posted by Vylen Quote
No, the blinds are as straight as can be - the horizontal panes anyway - you can verify that based on the window itself and the top of the fence.. no guarantee the stringy parts that hold them together are perfectly straight (and perpendicular to the panes/floor).

But, for checking the vertical for distortion, look behind the blinds and try use the fence as a guide

But yea, there's pretty much distortion across all focal lengths, but at least it would take some nitpicking at the bigger lengths in "normal" situations (at least, i think so)
Hmmm, maybe the blinds are fooling, looking at the "fence" or whatever it is outside the window, it seems fairly straight at fl 31 and forward....

This test will not do You'll have to do it again

Chose an horizontal objekt without any things infront or behind. A railing or building or whatever!

You're close to rep points
03-03-2011, 12:36 AM   #22
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I'll try the brick walls of my house... cause they're brick walls.. and should be perfectly horizontal

But it will have to wait till the weekend.
03-03-2011, 06:53 AM   #23
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Spent a litle time on Flickr looking at 18-135.

Here are some nice links:
Pentax K-r + DA 18-135 f3.5-5.6 ED AL | Flickr - Photo Sharing!

These two is kinda interesting, i think....
IMGP0532 | Flickr - Photo Sharing!
IMGP0534 | Flickr - Photo Sharing!
.....from this stream
IMGP0537 | Flickr - Photo Sharing!

From Digitalbear's stream. pictures of lens itself
Pentax K-r + DA 18-135 f3.5-5.6 ED AL | Flickr - Photo Sharing!


Edit: i have contacted forum moderators about a change in the title of the thread. I plan to soon get the lens myself and keep the thread going, and it should be a good spot for new owners (or potential ones) to come to.


Last edited by the swede; 03-03-2011 at 07:05 AM.
03-03-2011, 08:08 AM - 1 Like   #24
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Guys you should seriously consider going out more often or/and renting a studio with a naked model...

As i've said in another thread, 18-135 is a damn super-zoom lens!!! that's 28-200mm in FF terms for god's sake and it should be treated as such!!!

I owe one as well and it's the lens that spends the most time on the camera. The damn thing is very compact, sealed and it's the fastest-focusing Pentax lens to date... and IQ is good enough that I don't have to think about it...

In other words, is the best hiking and all-around lens on the market to date... But if you're expecting miracles from a super-zoom... perhaps you should stick to gardening or gold fishes...

Yes there's distorting all over the zoom range... so what? A little distorting doesn't heart when every second idiot can buy a decent camera and pretend to be a photographer... Photography was never about sharpness being eye-pooping sharp or straight lines being truly straight...
03-03-2011, 08:56 AM   #25
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QuoteOriginally posted by alexeyga Quote
Guys you should seriously consider going out more often or/and renting a studio with a naked model...
I dont know what you do with your time, and you do not know what i do with mine

QuoteOriginally posted by alexeyga Quote
As i've said in another thread, 18-135 is a damn super-zoom lens!!! that's 28-200mm in FF terms for god's sake and it should be treated as such!!!
Absolutely!

QuoteOriginally posted by alexeyga Quote
I owe one as well and it's the lens that spends the most time on the camera. The damn thing is very compact, sealed and it's the fastest-focusing Pentax lens to date... and IQ is good enough that I don't have to think about it...
Very good nice input! Thanks alot

QuoteOriginally posted by alexeyga Quote
In other words, is the best hiking and all-around lens on the market to date... But if you're expecting miracles from a super-zoom... perhaps you should stick to gardening or gold fishes...
Probably yes! Nope, i dont expect miracless. I asume none of us here do
Gardening? Ohh i wish i had a garden....

QuoteOriginally posted by alexeyga Quote
Yes there's distorting all over the zoom range... so what? A little distorting doesn't heart when every second idiot can buy a decent camera and pretend to be a photographer... Photography was never about sharpness being eye-pooping sharp or straight lines being truly straight...
Some might care, other might not!
You are absolutely right! Thanks for telling us that!
03-03-2011, 09:05 AM   #26
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Cross-posted from my K-r impressions thread:





















03-03-2011, 09:08 AM   #27
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@ deadwolfbones: Very nice set of images, they are all exellent. Good PP to!
03-03-2011, 02:13 PM   #28
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QuoteOriginally posted by alexeyga Quote
As i've said in another thread, 18-135 is a damn super-zoom lens!!! that's 28-200mm in FF terms for god's sake and it should be treated as such!!!
Yep, pretty much... Super-zooms have never been really known for zero-distortion...

However, as such, it should be nice to compare the amount of distortion in this super-zoom against other super-zooms... which would obviously would be helpful for people who are looking for a new super-zoom..

How many more times can super-zoom be mentioned in this post? .....

SUPER-ZOOM
03-03-2011, 05:11 PM   #29
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Wow those are some really nice shots! Distortion can be fixed in PP or on the K-7/K-5 itself, surprisingly fairly effective on camera distortion correction too.
03-03-2011, 09:42 PM   #30
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Has anyone tried Lightroom 3's distortion correction on this lens? We could even set up a profile to fix it automatically.
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