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Old Nov 3, 2007, 1:19 AM   #1
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I wasn't going to do any comparisons between my two lenses, since my DA 50-200 has significant problems (I can't believe that all of them are as poor as mine is). So I offer these in the "for what it's worth" category. They aren't exactly alike - in some cases I didn't get the focal length exactly right, in others I had the camera in "P" mode and it metered the scene differently. No one ever has to worry about me taking over lens reviews - I just can't quite get everything the same!

These pictures were taken in raw (forgot to change the camera to jpg for this) and converted with no change in Lightroom. I didn't do anything to them in photoshop (other than rename them so I could tell which lens I used for each picture) before uploading the full sized files to one of my zenfolio albums.

DA 50-200, 138mm:



Even on the reduced sized picture you can see the major problem this particular lens has. I'm across a plaza from this building, so the lenses were focusing at infinitym where the DA 50-200 has mostly shown it's problems.

DA*50-135, 135mm:



Ican see clearly that the problem is with the lens, not the camera.

This link goes to a full sizedfile (no resizing -LARGE FILES! so those on dial-up be warned)of another picture taken with the DA 50-200: http://mtngal.zenfolio.com/img/v2/p284379691.jpgand the DA*50-135 picture: http://mtngal.zenfolio.com/img/v2/p43371781.jpg- these were taken at 135mm, the subject is a measuring tape that was on the ground about a foot in front of me. The problems with the DA 50-200 aren't as evident when the object is closer, so I think these are more representative of the differences others would see between these two lenses.

If you are interested in seeing comparisons taken at other focal lengths (50, somewhere around 90 and 135, with a couple of 200 thrown in to show the amount of magnification you lose between 135 and 200), you can find them at: http://mtngal.zenfolio.com/p780316653/?photo=284379691- they were all taken at lunch today. At the top right there's a "send link"that opensa list of the addresses for various sizes, including the full sized file if you want to review it (open a new window and paste the link in it to see, just remember that these haven't been resized). Or if you move your mouse over to the left side of the picture, there's an icon for downloading the original file - I don't mind, these are pretty boring pictures. Bet you can imagine what I did with the DA 50-200 after I looked at the pictures, can't you?
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Old Nov 3, 2007, 10:53 AM   #2
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Harriet, were both of these at f/6.3? The exif is not present in the first one. It is too bad that your 50-200mm has not proven to be a good example but the 50-135mm looks good without comparison too. Of course, if you would like, I would be willing to let you ship your 50-135mm to me so I could do comparisons against my 50-200mm and let you know how it turns out! :-) Seriously, thanks for sharing these, I am very interested in both of the new Pentax zooms.

Tim
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Old Nov 3, 2007, 6:31 PM   #3
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how come you haven't sent that da 50-200 back to pentax yet for them to correct it back to spec? the problems you have with your copy are obvious.
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Old Nov 3, 2007, 7:48 PM   #4
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I'm surprised the first one lost it's exif - it was shot at f8 at 1/320 (as I said, I didn't think about changing to Av until later). In any case, at a smaller aperture and at infinity, there should be no trouble with limited DOF.

As far as why I haven't sent it back to Pentax for repair - I'm afraid of how much it would cost, it's no longer waranty, and I wonder if it could be fixed at all. The funny thing is that when it was new it seemed fine. I noticed when I got the K100 and took a bunch of comparisons with the DS and the K100 that I preferred the pictures taken with the kit lens, regardless of which camera took it, but didn't particularly notice the blurriness until a couple of months ago. It's gotten worse (much worse) since then. There's no sign of fungus and the glass isn't smudged - I don't know what's caused it to be so bad. It's also starting to suffer from flare, so I wonder if somehow the coating has failed.

Tim - I'd be happy to send you my DA 50-200 so you could take some comparison shots, but somehow I don't think that would be quite the same as what you suggested. If you really want to compare your DA 50-200 with my DA*50-135, come out here and we can go shooting somewhere together.
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Old Nov 4, 2007, 4:26 AM   #5
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mtngal wrote:
Quote:
As far as why I haven't sent it back to Pentax for repair - I'm afraid of how much it would cost, it's no longer waranty, and I wonder if it could be fixed at all. The funny thing is that when it was new it seemed fine. I noticed when I got the K100 and took a bunch of comparisons with the DS and the K100 that I preferred the pictures taken with the kit lens, regardless of which camera took it, but didn't particularly notice the blurriness until a couple of months ago. It's gotten worse (much worse) since then. There's no sign of fungus and the glass isn't smudged - I don't know what's caused it to be so bad. It's also starting to suffer from flare, so I wonder if somehow the coating has failed.
Hi Harriet,

I think that it would be worth sending it in to Pentax Service. All it would cost is the shipping there. They will send you an estimate before doing any repair, and if you don't agree, they will ship it back to you at their cost. I'd say that a very likely cause of the blurring is a misaligned lens element. If that were the case, then there is a small (probably very small) possibility that they would consider this a case where they might call it a clear mfg defect and repair it at no or low cost for good will's sake. It's worth a shot, IMO, especially if you don't use the lens a lot, and won't really miss it, which seems to be the case. Why not find out for sure what the problem is. . .

Scott
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