[altopiet]

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altopiet reported that green button metering doesn't work for his problem.

Correct, I've tried it, the problem is that it starts as an intermittent problem and then gets worse over time. With my "repaired" camera currently in the "intermittent" stage, Green button metering also works correctly but at some times (intermittently) gives wildly incorrect readings, which makes sense to me, as the process involves the same parts....

Regarding what Pentax should do, well I don't expect them to replace my camera or anything else, but as it seems that other models also have the same problem, it will probably keep nagging me when I decide to buy a new camera.
As I already stated, it will probably be a Pentax again, but never again jumping just after a new model release, I'll wait till end of a camera cycle, to see what problems develop, if any, before buying.
Perhaps my expectations of today's electronics and durability, compared to my K1000, is just way to high.
Luckily I've accumulated a lot of old manual lenses over the years, to play with, and will be able to use my K-30 for a while (barring any other problems), but not for any serious work...

[solatana]

Except we do know. Changing the solenoid makes the camera work again. If it was a power supply issue then the replacement solenoid wouldn't work either.
This is not speculation, I've changed the solenoid myself and now have a working camera. Others have too.


An aperture motor drives the aperture block and all gears in it. The solenoid controls the travel of the aperture lever, that's its only function.

In a german forum somebody had posted photos of the old aperture device and the new one:

Blendensteuerung K 30 Defekte ? Pentaxians

photo # 1-2-3 show the new device
photo # 4 and 5 show the old device

One can see, the device itself is different. But the solenoid seems the same one.

Member marabella has shown us photos of his K S1 which shows the same solenoid again in K S1:
K-S1 aperture block problem and possibly - a free and easy remedy - PentaxForums.com

Replacing the solenoid will likely work for some time, but how long if it is the same one again?

I believe Ricoh should manufacture a new solenoid.

---------- Post added 02-11-17 at 01:08 AM ----------

This is where I repeat, yet again, the comment I keep making.

How does repetition make an argument stronger? This is revolutionary!

All evidence is that this problem just magically appeared. A part that had been working fine stopped working fine. People here seem to assume that they are putting potentially bad parts into cameras as part of the repair process; if you say that, you are implying one of two things
(1) Pentax cannot tell the difference between good parts and bad parts
(2) Pentax doesn't care.

If you really believe #2, then you are saying "Pentax is evil", and you should immediately go to some other brand

If you really believe #1, then you should give them some grace.
People have said here that they no longer use that part, so new products should be fine.
KAF4 avoids the issue by no longer using that mechanism.
Unless you really believe #2, then you should admit that they have done all they can to put this behind them.

For the record, I do not believe that Pentax is evil

Does believe matter?
Believe is not made out of matter.
Facts matter! Facts are made out of matter. One can point at it. Proove something.

Your arguments are strange and narrow response down because they force readers to accept #1 or #2.
Only 2 options, other options do not exist.

so I like to add some extra options:

#3: Pentax has not yet come to realize which part produce the mistake
(possible proof: they only replace whole assembly/device)

#4: Pentax has come to realize but cannot admit: very common these modern days. All too common.

(#4 does not make Pentax evil but modern politics)

Your last argument:

KAF4 avoids the issue by no longer using that mechanism

Pentax still produces the K-S2 which has the same solenoid inside it, showing Ricoh has not come to some insight at time
of designing K-S2. But it seem that K-70 has still same solenoid but it is not in action when using KAF4 lenses of course.

This does not give any insight for all those who purchased K30-50-500 K-S1-2. They are stuck at least when using lenses
without KAF4.
K50 and K3 have now received firmwareupdate for KAF4.

Solution:
We cheaply sell our great old lenses and buy only KAF4. So easy.

[reh321]

I believe Ricoh should manufacture a new solenoid.

Pentax doesn't manufacture solenoids. This is a commodity product manufactured by some other {possibly multiple} manufacturer and put by various manufacturers into products of various level of sophistication. We don't know of any other use where it has had issues.

Does believe matter?
Believe is not made out of matter.
Facts matter! Facts are made out of matter. One can point at it. Prove something.

Actually, we have very few facts - most of what is said here is opinion. We know that certain members have experienced failures; there is reason to question whether they are the same failure involving the same part. Some here are of the opinion that this failure is widespread, but we don't know that. I used the word "believe" to clearly label my words as opinion; I could state them as fact if that would make you more comfortable, but my doing that would not change the fact that most words expressed here are opinion.

#3: Pentax has not yet come to realize which part produce the mistake
(possible proof: they only replace whole assembly/device)

OK, I stated #1 too narrowly; #1 should be that Pentax doesn't understand the problem; that covers everything from they can't tell good parts from bad parts to they can't tell what in the system is causing good parts to go bad

Solution:
We cheaply sell our great old lenses and buy only KAF4. So easy.

I assume you are aware that there is exactly one KAF4 lens for sale at current time, and Pentax has not yet released firmware update that would allow the K-30 to use KAF4 lenses.

Actually, there is another "solution" - use some of our great old lenses. Most M42-mount lenses can be used in a "manual" mode in which they are always stopped down. I have found a way of modifying my AdaptAll lenses so they never stop down {which I prefer to permanently crippling lenses by cutting off the aperture arm}.
Keeping AdaptAll Lens Stopped Down - PentaxForums.com

[solatana]

Pentax doesn't manufacture solenoids. This is a commodity product manufactured by some other {possibly multiple} manufacturer and put by various manufacturers into products of various level of sophistication. We don't know of any other use where it has had issues.

Nitpicking.
Actually 'we' should not even speak of Pentax but only Ricoh company, isn't it?
Which parts of K50 or K-S1 is manufactured by Ricoh? Or by whom? Maybe all parts are commodity product and all parts are assembled in Vietnam? Common issues.

Actually, we have very few facts

Wrong.
Actual is: Some people have done practical (actual) research by disassemble their K30 or K50 or K-S1 and made research, practical research.
This is f-actual.

"We - - - don't know". Who is we?
Maybe some people find they do know and have found this solution

- most of what is said here is opinion.

most of what *YOU* said here is opinion.

We know that certain members have experienced failures; there is reason to question whether they are the same failure involving the same part.

Bring evidence why there is reason to question about this being same failure/same part!

Some here are of the opinion that this failure is widespread, but we don't know that.

Repetion of the word "we" will as much not make your opinion into fact as endless repetion of zero will make zero into ONE.
Zero remains zero.

The failure is very wide spread. All over this planet called earth. I have studied research in Germany and Austria.

From members of forum we have over 50% failure (same issue/part) of Pentax K30:
K-30/K-50 Blendenproblem ? Wer ist (nicht) betroffen? ? Pentaxians
From 129 members of forum owning K30 it is 71 members having failed (all just one and the same problem)
From 77 members of forum owning K50 it is 20 members having failed (all as above)
K50 came out later, is younger.
Now we have first issues of repaired part (solenoid manufactured by ???) producing same problem again.

This, Sir, is evidence that solenoid is problematic part.
If one knows about magnetisation one can maybe better understand it.

AND: Foto Maerz, who is German Service for Ricoh, produced facts as well:
First before Ricoh found out about this problem, they replace whole aparture device
Then - after "we" (whoops) found out that sole-mio solenoid is problem, Ricoh service
replaces only solenoid. You can think further and not sink into alternative facts?

Now we take into account by guessing what happen to those people not taking part in survey.

My guess: Most user of modern camera are "automatic program user anyway"... not much concerned in Av, Tv, Tav and M mode.
What will such user do when K30 fail after warranty (here 2 years)? Become member of forum all sudden and tell their story. Daubt may be
allowed. I think they flush down the toilet. And buy new one. Maybe Canikon.
So we have zero idea about statistics which can somehow give slight hint or idea. None at all.
All we have is members of forum but this is very strong figure: 55% of all 100% K30 have failure!
This I call strong evidence and knowledge-base.

OK, I stated #1 too narrowly; #1 should be that Pentax doesn't understand the problem; that covers everything from they can't tell good parts from bad parts to they can't tell what in the system is causing good parts to go bad

There is some other possibility. In sequential order:
- Ricoh did not understand the problem. They repair by chaning whole circuit board including solenoid. Pricecharge for part roughly $ 125
- Ricoh finally understand that it is solenoid (when already very late and private people did research Ricoh engineers should have done so.
Now charge for part is simply $ 4.
# But: Ricoh not yet really understood what is deep inside, have not come to insight yet: Problem is how solenoid works. New solenoid will fail
again.

This, Sir, are facts which matter.

I assume you are aware that there is exactly one KAF4 lens for sale at current time, and Pentax has not yet released firmware update that would allow the K-30 to use KAF4 lenses.

who mention K30 in relation to KAF4? Not me.

Your quote was:

People have said here that they no longer use that part, so new products should be fine.
KAF4 avoids the issue by no longer using that mechanism.

Your suggestion was that KAF4 is solution which I questioned. Because I am more than aware we have only 1 lens using KAF4.
Also your argumentation was wrong saying "new products should be fine". If solenoid brakes down on K-70 it is not fine.
KS-2 is still new product. It uses same solenoid.

You see, to you one has to repeat and repeat as well, but it is different use of repetition. It is to try to make you look at something
you obviously deny to take a look at: Facts which matter!

Actually, there is another "solution" - use some of our great old lenses.

Rather strange argument: After all it just has meaning: "Put up and shut up"

If I want to use manual lenses or stopped down lenses I want this to be my choice and not be forced into by
"put up and shut up". Better come up with something better.

Most M42-mount lenses can be used in a "manual" mode in which they are always stopped down.

Wrong: Almost all Takumar lenses are like this, you are right here. Quite some few Zeiss as well.
But not "most". Many many M42 lenses have no manual to auto switch.
Some Takumar (like 58mm) have not this option.
Many K-mount lenses which are manual might need modification to be always stopped down.
But lose value for collectors.

But this is missing the point. Point is that who purchases for example K-S2 wants it to work. For me I was thinking of selling my K-S1 and buying
K-S2 but now I will not. K-70 has same solenoid inside as well. So who will buy K-70 when Ricoh not solve this problem?

I have found a way of modifying my AdaptAll lenses so they never stop down {which I prefer to permanently crippling lenses by cutting off the aperture arm}.Keeping AdaptAll Lens Stopped Down - PentaxForums.com

Good solution. but I don't like AdaptAll Lenses. Zooms to heavy, SP90 outcasted by other macro lenses. No really useful prime otherwise except maybe MF90 version of SP90.

[reh321]

Nitpicking.
Actually 'we' should not even speak of Pentax but only Ricoh company, isn't it?
Which parts of K50 or K-S1 is manufactured by Ricoh? Or by whom? Maybe all parts are commodity product and all parts are assembled in Vietnam? Common issues.

No, it is a statement of truth. Ricoh Pentax did not make these solenoids, and they are not going to start making solenoids now. Unless you have some unreported data, no one knows what about these solenoids contributes to problems in these systems, so getting anyone to manufacture ones that fit into the current systems and work correctly forever would be a problem.

The failure is very wide spread. All over this planet called earth. I have studied research in Germany and Austria.

From members of forum we have over 50% failure (same issue/part) of Pentax K30:
K-30/K-50 Blendenproblem ? Wer ist (nicht) betroffen? ? Pentaxians
From 129 members of forum owning K30 it is 71 members having failed (all just one and the same problem)
From 77 members of forum owning K50 it is 20 members having failed (all as above)
K50 came out later, is younger.

Then you know that "polls" where people self-report are known to be inaccurate, because response rate for those with problems is much higher than others. In this case, if the K-30/50/500/01/s1/s2 had failure rate of 50%, then there is no way that Pentax's overall rate would be 7%, within a statistical tie with all the other companies. (see #16 way above)
K-30 / K-50 Aperture Block Failue - Repair Solution available - Page 2 - PentaxForums.com

This, Sir, is evidence that solenoid is problematic part.
If one knows about magnetisation one can maybe better understand it.

Have you read through this entire thread?? There is talk of magnetization, but also of weak/broken springs, of lubrication, etc. The people who have actually touched this mechanism don't seem to agree on what is going on.

Now we take into account by guessing what happen to those people not taking part in survey.

My guess: Most user of modern camera are "automatic program user anyway"... not much concerned in Av, Tv, Tav and M mode.
What will such user do when K30 fail after warranty (here 2 years)? Become member of forum all sudden and tell their story. Daubt may be
allowed. I think they flush down the toilet. And buy new one. Maybe Canikon.
So we have zero idea about statistics which can somehow give slight hint or idea. None at all.

So you reject my opinions and then put forward your guess?

[niceshot]

it can be one of three things, 1 solenoid 2 mirror motor 3 shutter block. Or 4 motherboard. My advice quit trying to play EINSTEIN.

[madphys]

I think someone didn't quite got the figurative speech and took things too bluntly. It doesn't matter weather Ricoh manufactures solenoids or sources them somewhere - as people say - S**T has happened, and now it should be cleaned up. It would be only polite if Ricoh publicly would announce that there has been a problem, they know the cause, and people do not need to panic or worry, because all current models have quality parts in them. I haven't seen such an announcement - and I think it casts an unpleasant shadow on Ricoh. Doubts have been seeded - and they are serious (looking through Russian forums - many people report this problem - also K500 are massively affected). People are becoming hesitant of buying another Pentax - especially entry level camera. I hope this is not a part of their long-term strategy to sell more K3s and KPs...

[athlonus]

As I read all the posts since my last post, all I see here is lots of vague conversations... do not take personally, I am sorry to tell you the truth.

Take my word who is in the repair business for a long time and worked with Japanese teams designing cameras.

The culprit is the new CHINESE MADE plunger solenoid. It is out of voltage specs and it MUST be replaced with a quality Japanese product such as Panasonic, Alps or Mitsumi made.

Filing the part is quite laughable especially when you need to reopen your camera when it fails in a short while.

Mirror box, Shutter and main board has NOTHING to do with that.

Nikon, Canon, Olympus and Minolta has similar mechanism utilizing the same solenoid in a different location due to patent issues.

Nikon D3 and D4 has been upgraded to step motor control due to a different shaped solenoid failure which controls the aperture and it causes the 'Err' message on the early prototypes (which was very common in D2H)

Canon does the aperture in the lens to prevent the same issue.

Replace the part if you can find it and be all set. Pentax is a well engineered brand and has nothing less than the others.

[solatana]

Member marabella has shown us photos of his K S1 which shows the same solenoid again in K S1:
K-S1 aperture block problem and possibly - a free and easy remedy - PentaxForums.com

Replacing the solenoid will likely work for some time, but how long if it is the same one again?

I believe Ricoh should manufacture a new solenoid.

Pentax still produces the K-S2 which has the same solenoid inside it, showing Ricoh has not come to some insight at time
of designing K-S2. But it seem that K-70 has still same solenoid but it is not in action when using KAF4 lenses of course.

No, it is a statement of truth. Ricoh Pentax did not make these solenoids, and they are not going to start making solenoids now.

This is why I named your response "Nit-Picking". Aside of being a statement of truth, because it is totally unimportant.
And yet: If I understand small difference in your native language correctly:
If I write: Ricoh should produce a new solenoid, it could be correct. But this word "produce" was not ready on this springboard in my brain,
instead the word manufacture slipped in. I feel very embarrassed and apologize.

Unless you have some unreported data, no one knows what about these solenoids contributes to problems in these systems, so getting anyone to manufacture ones that fit into the current systems and work correctly forever would be a problem.

One does not need unreported data but use common sense by using reported data. Actually I believe Ricoh know knows about this problem very well and engineers will solve this problem with solenoid and "produce" some solution for future camera devices, manufactured of course not by Ricoh but as you quite correctly wrote... May the 4th be with you...

Pentax doesn't manufacture solenoids. This is a commodity product manufactured by some other {possibly multiple} manufacturer and put by various manufacturers into products of various level of sophistication

But--alas-- you actually bring a new possibility, some real insight into all this (but you have not realized you did): This could well be the source of
the problem: possible multiple manufacturer! So it can be, that one of these manufacturers produces bad solenoid.

But: usually when comparing electronic devices, I have found one can see some slight difference in colour. For example of the circuit board.
But this solenoid looks always same to me.

But the problem could be --- again you pointed this out --- that bad copper was used for winding the coils.
But usually bad copper as I have found in chinese mains transformers, produces burned coil, no transition in ohms can be measured.

I think / guess: Magnetisation it is.

Then you know that "polls" where people self-report are known to be inaccurate, because response rate for those with problems is much higher than others. In this case, if the K-30/50/500/01/s1/s2 had failure rate of 50%, then there is no way that Pentax's overall rate would be 7%, within a statistical tie with all the other companies. (see #16 way above)
K-30 / K-50 Aperture Block Failue - Repair Solution available - Page 2 - PentaxForums.com

An interesting way to argue with: "Then you know". I must remember this.

No, I do not know that it is common knowledge that those polls are inaccurate. But "you know" that you make assumptions and turn them into facts. In this German forum members received message to report. I assume that here we have a relative accurate picture of members of a forum
owning K30s and K50s have done relative proper work.
And we (in Germany and Austria) know, that Foto Maerz (Ricoh service here) knows very well about this "common problem".

Have you read through this entire thread?? There is talk of magnetization, but also of weak/broken springs, of lubrication, etc. The people who have actually touched this mechanism don't seem to agree on what is going on.

It is not so much a question of agreeing or disagreeing but I assume those people are not engineers on this field.
I guess that engineers would have found a solution (if they are good of course). My respect to those who found out actually what Ricoh engineers should have found out since long time!

So you reject my opinions and then put forward your guess?

It is very easy to have an opinion. Everybody has an opinion. To make an effort of finding out (such as you did with AdaptAll lenses) is what counts.
They took their K30 or K-S1 apart and made photos. Also there was effort made to translate. This I value. I have high respect for it.
Opinions for sake of arguing? Not so much value. But opinions which water down: I do not just reject. I eject.

By the way: What is your way of dealing when you are proven wrong?
When it is clear?
Do you respond?
Or do you (just) ignore?

---------- Post added 02-11-17 at 11:49 PM ----------

Except we do know. Changing the solenoid makes the camera work again. If it was a power supply issue then the replacement solenoid wouldn't work either.
This is not speculation, I've changed the solenoid myself and now have a working camera. Others have too.

In some cases it could be a power supply issue:

The Pentax K r had a mirror flop issue. A possibility why this happened is that the power supply of the K r was taken over from the K x.
The K x allowed for NiMh batteries only, but the K r allowed for Li-Ion as well. Two types being different. Bring different stress on the power-supply when being charged and in other situations. Different curves.

The Pentax K-30 and K-50 allowed via adapter to use NiMh batteries. Maybe this can lead to problems.

Ricoh stopped those adapters for other cameras. Possibly with strong reason behind.

Modern business is hard. Ignoring very common.

[solatana]

THANK YOU!

As I read all the posts since my last post, all I see here is lots of vague conversations... do not take personally, I am sorry to tell you the truth.

Somehow I sadly did not hit onto your previous posts.

No need to feel sorry about telling the truth:-)
For me more than welcome. Now I really feel sorry that my K-50 is sold, I would dare to take on this repair.

Take my word who is in the repair business for a long time and worked with Japanese teams designing cameras.

It is good to hear from somebody with experience.
Strange that some members read your posts and yet remain glued to ??? whatever it may be.

The culprit is the new CHINESE MADE plunger solenoid. It is out of voltage specs and it MUST be replaced with a quality Japanese product such as Panasonic, Alps or Mitsumi made.

As I wrote in one of my last posts, I have made similar experiences with chinese mains-transformers. Partly very bad copper. It was Japan who
invented once super clean copper (5N, 6N) for special use. So China invents super dirty copper -5N -6N. Sometimes it is just old copper including insulation melted down together. I never forget when once I had problem with some lovely lamp from Africa. Something smelled badly in the switch.
I opened switch and saw burned copper in mains lead. I cut it to install better switch. But cutting back insulation on mains lead showed more bad like burned copper. It was blackish.
In the EU we now very often have problems with bad parts for cars such like brake discs produced (or must I say manufactured?) in China.
Terrible compare to real quality. Last only 1/3rd of time and quickly rusty. Same for brake cylinder. Stuck again after just 6 month use.

Filing the part is quite laughable especially when you need to reopen your camera when it fails in a short while.

But it lead to further research.

Mirror box, Shutter and main board has NOTHING to do with that.

This was my guess as well.

Nikon, Canon, Olympus and Minolta has similar mechanism utilizing the same solenoid in a different location due to patent issues.

Nikon D3 and D4 has been upgraded to step motor control due to a different shaped solenoid failure which controls the aperture and it causes the 'Err' message on the early prototypes (which was very common in D2H)

Canon does the aperture in the lens to prevent the same issue.

Replace the part if you can find it and be all set. Pentax is a well engineered brand and has nothing less than the others.

I have my vintage K10D which has some damage because it badly fell. Still works partly but not all programs anymore.
So I will for sure keep as solenoid inside is proper Japan made one.
Very good for possible repair of my K-S1.

You see, I pointed at this exactly same looking solenoid in K30-50-500 and K-S1 and K-S2.
And I brought link to forum in Germany with photos of old circuit-board and new circuit-board.
Both have same solenoid. Made in China it must be.
Now Ricoh service in Germany use just solenoid and not anymore circuit-board.

So we have no first "service-repaired" K-30 and K-50 failure, but out of warranty for repair. Too bad luck.
Repair then was EUR 250 with circuit board.
Now repair is EUR 125 about with just solenoid. Customer who want his K30 repair must ask Ricoh first for special out of warranty bonus/treatment.
But actually this is bullshitting from Ricoh Germany because they say: Yes, we allow cheaper repair. But they just send EUR 4 item instead of
more expensive circuit board (which cost them possibly pee-nuts) which is solenoid and the other cost is for work itself anyway.

So I name such behaviour after famous American Indian and make addition of "h" (for hilarious)
and make it "S-h-itting Bull" for who produces such pseudo bonus!

I hope nobody now feel offence?!

By the way: All here in USA know about bad behaviour of Volkswagen for their cars. It is tip of iceberg. More companies now all over world
in trouble: Japanese, Sweden, Italian and US made as well. But made in EU for EU only. But same lies.

Modern companies have strong competition. If one undertakes study of link between Pentax and Japanese beer, one can get some insight.
Same econonic war. Same stupidity.

[madphys]

The culprit is the new CHINESE MADE plunger solenoid. It is out of voltage specs and it MUST be replaced with a quality Japanese product such as Panasonic, Alps or Mitsumi made.

Do you think these Chinese parts are an old stock that has been put to use? If you are in the repair business maybe you know (have seen) - are the newer K50s, k70s etc equipped with better quality parts? Also - can these solenoids be acquired by a regular person - let's say at the Mouser or DigiKey or are they a special order?

[reh321]

I have studied research in Germany and Austria.

Then you know that "polls" where people self-report are known to be inaccurate, because response rate for those with problems is much higher than others. In this case, if the K-30/50/500/01/s1/s2 had failure rate of 50%, then there is no way that Pentax's overall rate would be 7%, within a statistical tie with all the other companies. (see #16 way above)
K-30 / K-50 Aperture Block Failue - Repair Solution available - Page 2 - PentaxForums.com

No, I do not know that it is common knowledge that those polls are inaccurate. But "you know" that you make assumptions and turn them into facts. In this German forum members received message to report. I assume that here we have a relative accurate picture of members of a forum owning K30s and K50s have done relative proper work.

I am mostly retired now, but my career alternated between working as a software engineer and teaching computer science, basic electronics, and math {such as statistics} at lower-tier colleges in the US. In the US, statistics is commonly an essential part of "research". The textbooks commonly used to teach statistics specifically mention self-reporting as an issue to be avoided when conducting research. In saying "then you know" I was simply showing respect for your European training. I am sorry you were offended.

[solatana]

Do you think these Chinese parts are an old stock that has been put to use? If you are in the repair business maybe you know (have seen) - are the newer K50s, k70s etc equipped with better quality parts? Also - can these solenoids be acquired by a regular person - let's say at the Mouser or DigiKey or are they a special order?

Allthough you not posed this question to me but athlonus, maybe this can be of help:

I have posted already links to the German forum.

There you find photos of the old and new device, as well as in photos showing K-S1 and K-S2.

The solenoid made in China has a green body:
Blendensteuerung K 30 Defekte ? Pentaxians

The solenoid made in Japan also sold in ebay is white or better transparent:
Pentax K-30 K-50 Genuine Aperture Solenoid Plunger Part - Made in Japan - | eBay

Magnet Solenoid for Use in Cameras, Cellphones, Stereos and Other Portable Devices on Global Sources

and it can be found as well in "ageing walking men":
http://www.petervis.com/walkmans/WM-EX612/WM-EX612%20Deck%20Mechanism.html+

---------- Post added 02-12-17 at 09:29 AM ----------

I am mostly retired now, but my career alternated between working as a software engineer and teaching computer science, basic electronics, and math {such as statistics} at lower-tier colleges in the US. In the US, statistics is commonly an essential part of "research". The textbooks commonly used to teach statistics specifically mention self-reporting as an issue to be avoided when conducting research. In saying "then you know" I was simply showing respect for your European training. I am sorry you were offended.

we have a saying in German:

"Don't trust any statistics which you haven't forged* yourself!"

*faked is meant with this or course, not forging japanese sword

Sometimes statistics can be very useful.

And yes, self-reporting tax-evation for example will not produce reliable results.
This is good example when statistic will fail (tax-evation) but in this case of K30 aparture problems we have enough reliable results.
Statistics or self-reports don't matter really, just pointing at strong issue.

But alas-- you see-- all this work did lead to something!
That is most important

[reh321]

we have a saying in German:
"Don't trust any statistics which you haven't forged* yourself!"
*faked is meant with this or course, not forging Japanese sword

In the US we say "Figures don't lie, but liars do figure"

And yes, self-reporting tax-evasion for example will not produce reliable results.
This is good example when statistic will fail (tax-evasion) but in this case of K30 aperture problems we have enough reliable results.
Statistics or self-reports don't matter really, just pointing at strong issue.

My original point is that the results we have concerning the K-30/50/500/...etc. are not "reliable" in that statistical sense - we cannot extrapolate from them and have a reliable estimate of what the overall population looks like. Unless these lower tier products are an insignificant portion of Pentax's business, there is no reasonable way to reconcile them with reliable {such as those by Consumer Reports} measures of overall failures. They are a great measure of dissatisfaction by PF members {as though the "replies" and "views" counts for this and related threads didn't provide that}, but the nature of how the data was collected limits their "predictive power".

[JayDee]

Sure are a lot of strong opinions in this thread...

Just wanted to report back that my 'laughable' filing technique has been working for almost 1000 exposures so far. Of course, I can't say it will work forever, but so far so good.