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11-26-2013, 11:57 PM   #16
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QuoteOriginally posted by interested_observer Quote
snip

Customer Service.....
Pentax has done it before. I hope someone in an actual position of authority sees this, as once they realize the situation, they won't fail to deliver. At least I hope so

Best of luck to you DL.

-Heie

11-27-2013, 09:25 PM   #17
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This thread and the other is not giving me a warm and fuzzy. I just dropped some major coin on this lens

Good luck!
11-28-2013, 04:50 AM   #18
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QuoteOriginally posted by cali92rs Quote
This thread and the other is not giving me a warm and fuzzy. I just dropped some major coin on this lens

Good luck!
This is one bad sample. There are hundreds of these lenses out there that perform perfectly including my own.
11-28-2013, 11:20 AM   #19
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I would make sure that you are perfectly perpendicular to the paper you are photographing. One way to do this is to place a small mirror in the center of the paper. If you are perfectly perpendicular to the paper, you will see the reflection of the camera and lens in the mirror.

11-28-2013, 01:01 PM   #20
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QuoteOriginally posted by pentaxman Quote
I would make sure that you are perfectly perpendicular to the paper you are photographing.
Good point.

Under the conditions indicated by the OP and the EXIF data - FL 250 mm, subject distance 4 feet, f/4 - the total depth of field is approx 3 mm, or 1 mm in front of the focus plane and 2 mm in rear. That is a very tight margin, and practically any misalignment of the camera sensor plane off the perpendicular to the flat subject would introduce 'focus blur.'
11-29-2013, 06:50 PM   #21
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Yes, I made sure it wasn't off and that the surface was flat. It's a reproducible defect. BTW, I redid this test and the distance to the subject is 5 ft, not 4 ft.

It may not be obvious at longer distances (> 15 ft), but it reproduces on several different flat subjects at short range.

I can also confirm that it is focusing closer on the right side than on the left: if shooting a flat surface slightly from the right, more of the image will be in focus than if shooting at the same angle to the left.

Edit: The problem no longer reproduces. Is it possible that I am experiencing an intermittent fault?

--DragonLord

Last edited by bwDraco; 11-29-2013 at 07:34 PM.
11-29-2013, 07:26 PM   #22
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DragonLord: your Acer comment made me chuckle.

The least desirable service experiences with manufacturers I've had in my life were with Acer and Pentax. That's it. Just those two.

The issue I had with Acer was 15 years ago. I never bought another one of their products.

Pentax, conversely, keeps sucking me back in.
11-29-2013, 07:27 PM   #23
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QuoteOriginally posted by stormtech Quote
This is one bad sample. There are hundreds of these lenses out there that perform perfectly including my own.
You touch on an excellent point. There are variations in all manufacturing processes. The slight variations in one part are usually mitigated by another. The system when assembled, tested and tuned/adjusted through QA/QC usually brings the assembled unit into specification pretty easy. However, there are times - when Murphy is visiting, that all of the variations in the parts work against you (what ever that probability is) and you wind up with a unit that is the outlier (all the variations are cumulative in the wrong direction). When this happens, to my way of thinking, these units are very special to the manufacturing engineer. In warranty repair, these units that are difficult to repair (the second/third time around) needs to be found/identified - pull them and get them back to Japan for tear down and analysis for a root cause evaluation. This is the way that you can really improve the overall system manufacturing process that in turn will produce larger positive future dividends.

On the other hand - these units are maddening to the end user (and warranty repair), and create posts like this thread. Pentax can really help themselves here - trade the unit out, for one that is known good. Build up the overall customer experience, while helping yourself by figuring out the basic systemic cause and fixing that too. One rock - two birds.



11-29-2013, 07:28 PM   #24
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I can't seem to reproduce this consistently. Intermittent fault? Anybody's guess...

One thing I can say is that the lens seems to be throwing off both the phase detection and contrast detection AF systems. Maybe this is part of the issue?

Edit: It is an intermittent fault. The SDM sometimes, but not always, makes a bit of a friction noise, which also occurs when turning the focus ring manually. This noise may be more noticeable on one side of the lens than the other. Since this doesn't happen all the time, it's safe to say that the focusing lens group is loose, causing it to slip out of place at times. The noise only occurs when the lens is at or near the telephoto end.

Recording here: http://vocaroo.com/i/s1TVm42VFZYO

--DragonLord

Last edited by bwDraco; 11-29-2013 at 08:24 PM.
11-29-2013, 10:13 PM   #25
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I would be incandescent with rage by now.

From the description I think it's clear that the lens has not been properly repaired: faulty work and/or parts.

Don't continue your pain, testing and retesting, thinking that somehow its your fault and living in the vain hope that somehow the problem will fix itself. Trust your eyes and experience, not the repair centre report.

The repair centre has let you down (twice!). Contact Pentax for a replacement 60-260, and do not settle for anything less.
11-30-2013, 12:28 AM   #26
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I took a closer look through the mount end of the lens, and found a nasty surprise:




This long scratch on one of the elements of the focusing group shows just how incompetent the repair technician was. Several other scratches were also observed at different angles. I always expected C.R.I.S. to do a decent job repairing lenses, but they F'ed up the lens instead.

--DragonLord
11-30-2013, 01:10 AM   #27
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Bring this up with Pentax USA and the BBB. CRIS should be hung.
11-30-2013, 03:28 AM   #28
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QuoteOriginally posted by stormtech Quote
This is one bad sample. There are hundreds of these lenses out there that perform perfectly including my own.
I love how the apologists come out when not even needed.
11-30-2013, 01:30 PM   #29
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The Pentax service solution in the US is atrocious. Don't ask me how I know.

Aspiring professionals run away until this situation improves. At least with the other makes you have choice when it comes to service.
11-30-2013, 01:44 PM   #30
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QuoteOriginally posted by snake Quote
I love how the apologists come out when not even needed.
A bad experience can change your thinking on these matters. I recall the many threads and posts about the DA*16-50 SDM failures and wondering about how seriously I should take them, until mine failed. However, similar complaints about the DA*60-250 seem to be far fewer in number. Simply pointing this out doesn't make anyone an apologist, any more than highlighting a failure makes that person a whinger. This instance, on the other hand, indicates a serious failure in repair service, rather than in manufacture, even though that's where it started. Pentax service in the US should be looking a fair bit harder at their procedures and personnel, from the looks of this.
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