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05-22-2018, 10:56 PM   #31
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QuoteOriginally posted by bwDraco Quote
Hence, this does not rule out delamination as pressure can cause sub-surface bubbles to disappear, but it does suggest it could just be oil or other contamination.
Are you saying there is liquid inside the mirror?


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05-22-2018, 10:59 PM   #32
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Bubbles could just be voids between the surface and substrate. I can't really tell the difference between contamination and delamination at this point.

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06-03-2018, 12:59 PM   #33
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QuoteOriginally posted by bwDraco Quote
My Pentax K-3 II has been suffering from occasional focusing problems where the camera may lock focus far off target at times even in good light on a high-contrast subject. The error is typically front-focus but can sometimes be back-focus, and cannot be addressed by AF fine adjustment because of its inconsistent nature. The behavior also appears to be somewhat dependent on color temperature. All of my lenses are affected.

I tried cleaning the AF sensor with a blower bulb and while it appears to have improved, it did not completely address the problem. Should I try again, or send in the camera?

Has anyone else sent in their cameras to Precision for this issue, and did they address it effectively? If I'm to send mine in, should I send in the lenses as well? The camera is out of warranty, but that's not an issue for me.

Draco




It turns out the problem is delamination of the AF sub-mirror. How this is even possible is beyond me, but it looks like this will have to be sent to Precision.




Anyone else experienced this issue? Here's the note I'd send with the camera:


Draco
I was having the same issues on one of my K3 bodies, and found the AF mirror looked like your first photo. It did not look like that on the other K3. I used a sensor cleaning swab (dry) to wipe them off and they appear to be completely gone. Autofocus is greatly improved. Mine were the spots, not the flowing discoloration. I will see how much this has helped after a few days of use.

Last edited by GeneV; 06-03-2018 at 02:57 PM.
06-13-2018, 02:25 AM   #34
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Stumbled upon this thread by accident, but I have the same problems as the original poster where auto focus is a bit unpredictable, especially in low light. So I checked the AF mirror on my K-5 and ofc there are spots on the mirror. I also seem to have a line of dots in the middle of the mirror. I did buy the camera used, but I don't think the original owner messed around in the mirror area. My guess is that there has been a hair stuck there that has left traces of oil or grease, the spots are the same shape and form like the solitary spots. But even if there is a scratch, I'm hoping that cleaning it might get rid of the circular spots in the area and hopefully improve auto focus. Using a rocket blower didn't help so now I'm thinking about trying to clean it (really carefully) possibly using isopropanol alcohol (99.5%) and some kind of cloth or swab. Would a pice of unused microfiber cloth for optics be too abrasive? I have a unopened microfiber cloth for optics at home, and there is no store around where I live where I can buy camera related things. So I would prefer not having to order stuff online and wait for it to arrive

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07-02-2018, 07:18 AM   #35
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An update to my previous post: Managed to clean the mirror using pecpads and isopropanol. Havent had much time to test if it helped the slightly erratic auto focus in low light, but at least it looks much cleaner now
08-15-2018, 07:50 PM   #36
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Late reply, but I have inspected the AF sub-mirror again and the spots have reappeared, exactly where they were before I tried to "clean" them". The camera has seen very little use over the last few months. At this point, I am absolutely convinced that this is delamination and not contamination.

Ricoh seriously needs to know about this.

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08-16-2018, 04:15 PM   #37
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It's been sent to Precision for repair. I've made it very clear on the letter inside the package that the AF sub-mirror is delaminating and must be replaced, not merely cleaned.

The camera is out of warranty. My first job of the next season is September 1, so I'm paying for an expedited repair. Furthermore, I've shipped it out via Priority Mail Express for guaranteed overnight delivery, something I don't usually do.

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09-19-2018, 09:42 AM   #38
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@bwDraco,

Would you have any news on the repair? Thanks.

- Craig

11-16-2018, 05:58 AM   #39
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QuoteOriginally posted by bwDraco Quote
It's been sent to Precision for repair. I've made it very clear on the letter inside the package that the AF sub-mirror is delaminating and must be replaced, not merely cleaned.

The camera is out of warranty. My first job of the next season is September 1, so I'm paying for an expedited repair. Furthermore, I've shipped it out via Priority Mail Express for guaranteed overnight delivery, something I don't usually do.

Draco
I'd like to hear some updates too.

I just recently bought a used K3. It has like ~30 spots on the submirror. Sometimes the focus refuses to focus, kinda hunts around the spot or simply misses by a mile.
I don't know if it's delamination or some pollen/dust, haven't tried swiping the mirror yet.

I do know that my K50 and K500 both have the same spots on the submirror. Both have seen fairly good use at 50k+ shuttercount.

*I do hope it's just some dust on my mirror
** And it probably isn't. I just wiped it with a clean Qtip. The spots disappeared. No residue. I hope they don't come back.

Last edited by labidas; 11-16-2018 at 06:12 AM.
11-16-2018, 06:15 AM - 1 Like   #40
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I'm reacting to the OP's statement that the camera is "out of warranty". What people don't get is that a warranty is not a period of time in which you can get something fixed for free. That has to do with available remedies for the breach of the warranty, and not the warranty itself. Most of the confusion is due to a federal (U.S.) statute called "the Magnussen-Moss Warranty Enforcement Act", which I believe was designed specifically to muck up the waters for consumers.

A "warranty" is a promise that is made at the time of purchase that the product will conform to certain standards, levels of quality, functionality, etc. It is breached, if it is at all, at the time the promise was made (i.e., at the time of purchase). The statute of limitations on breaches of warranty under the Uniform Commercial Code is generally four years. So if there was a manufacturing defect present at the time of purchase, you have four years within which to file suit for breach of warranty, irrespective of limitations on the time in which the manufacturer promises to fix for free (which constitutes an entirely separate warranty, by the way). That will all depend on the laws of the individual state in which the purchase was made, of course, whether that state be Maryland or Scotland.
11-16-2018, 07:13 AM   #41
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I must have missed this thread when it first appeared. I will need to check my K-3 later but this could possibly explain the sometimes less than accurate focus I get from it (which I had previously put down to it just being a Pentax).
11-16-2018, 10:07 AM   #42
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QuoteOriginally posted by dlh Quote
What people don't get is that a warranty is not a period of time in which you can get something fixed for free.
The funny thing is that the warranty contract (what counts in court) details the faults covered, the remedies, and the limits under which it will be offered. (The word "warrant", after all, simply means an official statement promising action.) Where statute applies (assuming statutes exist) is when the warranty contract was offered in bad faith or where there is statute with provision for reasonable service life for expected purpose. Bad faith is difficult to assign unless there is evidence that the conditions of the contract make it difficult if not impossible to pursue remedy or if the nature of the fault itself creates an "out" for the manufacturer. Failure of weather seals may fall into that latter category.

Breach of warranty is when the seller does not honor the warranty contract (i.e. does not provide remedy for fault as defined in the contract). As you noted, the statute of limitations does not extend the contract, but does determine the period of time within which a complaint may be made. Problems that occur outside the provisions of the warranty contract might still be remedied by the manufacturer, but as a matter of good will outside of contractual obligation.

Implied warranty is the notion of reasonable service life and suitability for purpose. A good example might be that a boat should float and should be reasonably durable to that task over time. If the boat fails as a snow sled or sinks after being crushed under a breaching whale, no reasonable person would assume bad faith on the part of the maker. However, if the hull materials have been shown to dissolve slowly when exposed to water resulting in physical harm to passengers, that would be another matter.

As for the reported secondary mirror issues, an implied warranty might be applicable unless the camera is close to or beyond a reasonable service life. For sake of argument, that might be considered as three or five years of professional use in much the same sense as a computer of copy machine for business.


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11-16-2018, 10:10 AM   #43
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@bwDraco...Any word as to how the repair went?


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11-16-2018, 10:31 AM   #44
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QuoteOriginally posted by bwDraco Quote
It's been sent to Precision for repair. I've made it very clear on the letter inside the package that the AF sub-mirror is delaminating and must be replaced, not merely cleaned.

The camera is out of warranty. My first job of the next season is September 1, so I'm paying for an expedited repair. Furthermore, I've shipped it out via Priority Mail Express for guaranteed overnight delivery, something I don't usually do.

Draco
What ever came of the repair?
11-16-2018, 11:06 AM   #45
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Does anyone know how those mirrors are made? I'm curious.
It seems to me they are lab-grown from different layers. Similar to how siliconwafers for microchips are made?
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