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03-20-2019, 08:43 AM   #286
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QuoteOriginally posted by Kerri-Ann Quote
Hmmm. thanks everyone for ongoing commentary from experienced perspectives.

It does seem the jury is still out on the K70 which I had been thinking of buying. It has a solenoid not stepper motor? But supposedly improved??
The KP seems a larger camera and more expensive.
I would rather buy new with appropriate warranties than try to do second hand. But it seems there are few Pentax stockists in rural France and online is the only choice. That makes it difficult to get a feel of a camera in your hand and when you are on the move...
A few months ago I made the statement "The main difference between the K-70 and the KP is build quallity" - and I was hit by a series of comments about other differences. I bookmarked that page for those times when I needed it, but I reinstalled Linux on this computer ten days ago and managed to lose all my bookmarks. I do remember that people believe the KP to have a better sensor also, but I don't remember the other advantages. Personally, the build-quality issue {including having a stepper motor instead of the solenoid} is enough to justify the price difference - the other differences are merely bonuses. The KP is basically a K-3 with a smaller battery, only one battery, no upper LCD, smaller queue buffer ..... the things that don't matter to me in any case.
QuoteQuote:
I do not want to attempt any repair myself and will probably keep the K30 body for use with my A Sigma 100-300 lens.
Thanks
Kerri-Ann
Without a working aperture control, the K-30 is still a fine camera for lenses which have an aperture-ring; that is how I'm using mine.

03-20-2019, 08:54 AM   #287
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QuoteOriginally posted by photogem Quote
That is the problem when you use google translations, they can give odd translations.

In the EU and Switzerland there are 2 years warranty. So any failures would not have been made public because people sent their cameras back for warranty repair.
Actually Ricoh Germany extended this warranty usually a bit longer, so this is why the first complaints where made about 21/2 years after the K30 and K50 came out.
I ran my K-30 on AA batteries once I became aware of this issue. The first aperture control failure occurred just about 3 years after I got the camera, and it became "permanent" about 3-1/2 years after I got it. Based on my personal experience, I would expect problems to appear within 4 years of getting the camera; the K-S2 has been out for 4 years now, so we can probably safely guess that the aperture control issue is less common in modern cameras than it was with the K-30/50, but solenoid-based aperture control is still less reliable than it was when Pentax first developed the KA-mount 35 years ago. Taking into account that this control is used in consumer-grade cameras only, this result should not be much of a surprise.
03-20-2019, 09:00 AM   #288
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QuoteOriginally posted by reh321 Quote
I ran my K-30 on AA batteries once I became aware of this issue. The first aperture control failure occurred just about 3 years after I got the camera, and it became "permanent" about 3-1/2 years after I got it. Based on my personal experience, I would expect problems to appear within 4 years of getting the camera; the K-S2 has been out for 4 years now, so we can probably safely guess that the aperture control issue is less common in modern cameras than it was with the K-30/50, but solenoid-based aperture control is still less reliable than it was when Pentax first developed the KA-mount 35 years ago. Taking into account that this control is used in consumer-grade cameras only, this result should not be much of a surprise.
One poster on the German forum said a Ricoh rep told him/her the K-30/50 were designed to last 4-5 years. I would hazard to guess this is the same for other consumer grade cameras like the K-S1, K-S2 and perhaps the K-70.
03-20-2019, 09:09 AM   #289
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QuoteOriginally posted by Not a Number Quote
One poster on the German forum said a Ricoh rep told him/her the K-30/50 were designed to last 4-5 years. I would hazard to guess this is the same for other consumer grade cameras like the K-S1, K-S2 and perhaps the K-70.
Yes, people focus on expected shutter life, but various different things can fail. The two Canon Rebels I had both had processor failures. I often tell the story of the Ford station wagon my parents purchased in 1958. Some year in the 1960's, the water pump failed while my uncle was driving it. The three brothers scoured junk yards in three states - they found 1958 Fords with no water pump, and 1958 Fords with broken water pump, but they never did find a good water pump, so that car eventually joined the collection of 1958 Fords with broken water pump in the local junk yard. Each mechanical item has a weakness - Pentax has constructed the rest of the parts in their consumer level cameras so well that the aperture control tends to be the weakness. I'm OK with that, because the camera is still usable, unlike the cameras in which the processor tends to fail first.

03-20-2019, 09:40 AM   #290
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QuoteOriginally posted by Not a Number Quote
One poster on the German forum said a Ricoh rep told him/her the K-30/50 were designed to last 4-5 years. I would hazard to guess this is the same for other consumer grade cameras like the K-S1, K-S2 and perhaps the K-70.
Can you supply a link to were this person made this claim.

Last edited by photogem; 03-21-2019 at 01:47 AM.
04-03-2019, 12:06 AM   #291
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My friend has a canon 60d, after a while when you turn on the camera one or two shots are normal, then an inscription appears - "the lens is not connected", the camera was used a little
this defect is not due to wear, but over time
he had an extended warranty and free repair was made under this warranty
04-05-2019, 11:35 PM   #292
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totally puzzled when Auzzie-Phoenix states "For those who do not have a lens with an aperture ring-

Step 1:

a.) Mount lens to camera.
b.) Set aperture setting in camera to a value where the lens iris will be fairly open upon shutter release.
c.) Look down into lens while under decent lighting, and press shutter button.
d.) Note whether iris opens up or stays narrow.

If during your testing, the aperture iris did not widen, then you more than likely have aperture block failure. You are free to try this with multiple lenses to rule out lens issues."


How can the iris "open up" when it is already wide open? How can it "stay narrow" if it is not "narrow" but wide open? When you mount ANY K mount lens on the camera and twist it into place the aperture is wide open and can be stopped down by either enabling the DOF function on the On/Off switch or taking the exposure, yes? Otherwise we would be looking through a very dark finder indeed. If the aperture control arm inside the mount was somehow stuck in a raised position you would immediately notice something amiss when you looked through the viewfinder and see it darker than normal.
04-06-2019, 03:42 PM - 1 Like   #293
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QuoteOriginally posted by Kerri-Ann Quote
That said... I am concerned by the implication in the threads that Pentax have this as a fatal problem across their range of DSLRs.
Having been a member here for about 9 years, I can't recall ever seeing any posts or threads that implied that the aperture block failure is universal across all Pentax cameras.

I own 4 Pentax digital cameras, *ist DL, K10D, K-5IIs, and K-1. Bought all of them brand new, and they are all still functioning perfectly today.

I also have a large array of film era Pentax lenses, all performing perfectly.

Pentax makes good quality cameras and lenses, always have, always will. But they are designed, engineered, and assembled by people, and people aren't perfect. So the products will never be 100% perfect. There will always be occasions when something doesn't go as it should.

So please don't avoid considering another Pentax model because the K-30 and K-50 have had these issues. There are plenty of proven cameras both used, and new that are available to choose from.

04-07-2019, 09:16 AM   #294
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QuoteOriginally posted by Kerri-Ann Quote
thank you Photgem and reh321 for your particular responses, and for links to previous explanations - very helpful in understanding the issues.
I am now in France and of course don't want a failing camera.
Ironically, i left my AA battery adaptor and Li-AA batteries at home as a weight saving action and, being in a country with power all the time, I thought it wouldn't be a fall back option needed (as eg in remote Nepal or out bush in Oz for weeks)

That said... I am concerned by the implication in the threads that Pentax have this as a fatal problem across their range of DSLRs.

Should I be looking to replace by body with another Pentax? If so which one is closest to K30 (but with improved noise ) Are K30s sold new now or are they only re-conditioned ones?

Or should i be looking elsewhere for a whole new kit? (Nasty question on a Pentax forum i know..)

THANKS
Kerri-Ann
Most K-30 and K-50 bodies on the market now are used - the K-30 I bought almost four years ago was used.
The K-70 is the current model closest to the K-30 - but Pentax seems to have redesigned the mechanism and it seems to work better.
I purchased the KP, which has a completely different mechanism.

The aperture control problem is not "fatal" - my K-30 still works, but I'm using it only with older lenses that have an. aperture ring allowing me to control aperture from the lens rather than from the body. My Canon Rebels had a fatal problem - the processor started acting flakey, then eventually didn't do anything. More expensive bodies, the K-7/5/3 line have a completely different mechanism that has never given any trouble that I know of - and the KP also has that mechanism. Incidentally, the Super Program I purchased in 1983 has essentially the same mechanism as the K-30/50, and it still works .... problems with this mechanism started only when a supplier changed the details of how they construct the solenoid.
04-07-2019, 04:41 PM   #295
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QuoteOriginally posted by Big Tim Quote
totally puzzled when Auzzie-Phoenix states "For those who do not have a lens with an aperture ring-

Step 1:

a.) Mount lens to camera.
b.) Set aperture setting in camera to a value where the lens iris will be fairly open upon shutter release.
c.) Look down into lens while under decent lighting, and press shutter button.
d.) Note whether iris opens up or stays narrow.

If during your testing, the aperture iris did not widen, then you more than likely have aperture block failure. You are free to try this with multiple lenses to rule out lens issues."


How can the iris "open up" when it is already wide open? How can it "stay narrow" if it is not "narrow" but wide open? When you mount ANY K mount lens on the camera and twist it into place the aperture is wide open and can be stopped down by either enabling the DOF function on the On/Off switch or taking the exposure, yes? Otherwise we would be looking through a very dark finder indeed. If the aperture control arm inside the mount was somehow stuck in a raised position you would immediately notice something amiss when you looked through the viewfinder and see it darker than normal.
this puzzled me a little at first but you have to consider that the failing solenoid is just one part of a more complex aperture control mechanism with motor driven gears & levers that cycle through the process, I would assume that even though the aperture is at first wide open when the cycle starts, it shuts down to minimum and then opens to the selected aperture from the minimum position. I can't recall ever seeing a full explanation of how the aperture control mechanism works (maybe i missed it I don't read everything here !) and what part the solenoid plays in this overall system and indeed why the solenoid actually fails, all we really know is a replacement solenoid is needed to fix the issue.
04-09-2019, 12:47 AM - 1 Like   #296
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Solenoid is not in action with manual lenses (green button)

QuoteOriginally posted by Cee Cee Quote
this puzzled me a little at first but you have to consider that the failing solenoid is just one part of a more complex aperture control mechanism with motor driven gears & levers that cycle through the process, I would assume that even though the aperture is at first wide open when the cycle starts, it shuts down to minimum and then opens to the selected aperture from the minimum position. I can't recall ever seeing a full explanation of how the aperture control mechanism works (maybe i missed it I don't read everything here !) and what part the solenoid plays in this overall system and indeed why the solenoid actually fails, all we really know is a replacement solenoid is needed to fix the issue.
I try to explain it, but here my English is not good enough!
Google translator would be as critical as in this case so it is not always that easy.

So I try:


The motor does not drive the aperture but lifts the mirror. But both work synchronized together of course.
The aperture must be wide open first (A or AF lenses). Otherwise there would not be that clear bright view through the viewfinder.
It does not shut down to minimum but just to the chosen aperture.

Green button methode (AE-L) with manual lenses:
Here the solenoid is not at all in action (incooperated)!
But the gear mechanism and the optical sensor is!
If the green button or the AE-L-button is pressed the aperture closes via those actually two gear-mechanisms which are syncronized with the shuttermechanism (also gears) and the optical sensor. The camera measures the needed exposure-time and then, when the shutter-release button is pressed, the mechanism starts but WITHOUT the solenoid!


I have an open K100D here which I use to show people how the mechanism works and which I use to show people sometimes that there are actually opposite polarized solenoids (from the analog MZ Series)


The white "plastic toothed wheel" sitting at the right side of the solenoid (plunger downwards) moves/turnes according to the aperture...i.e. more or less.
This picture shows also the optical sensor (very right with 4 wires: red, pink, turquoise, grey)
Behind this white toothed wheel sits a metall toothed wheel! This metall wheel has tiny openings within which give the sensor the correct position of the aperture.


The solenoid releases the plunger according to the length of the chosen shutterspeed.

When it releases, the aperture closes to the chose value (with AF and A lenses).
- If you chose TV = 2", the solenoid will release the plunger for exactly those chosen 2 seconds.
- If you chose TV = 20", the solenoid will actually release the plunger for those 20 seconds.
- But if you chose fast TV such as 1/1000, the solenoid cannot be that fast. You can still see the difference at 1/15 or 1/30, from 1/60 on it releases with about the same speed up to whatever max speed is possible for the chosen body.



This is the original Pentax patent:

US3631777A - Automatic camera shutter - Google Patents

Complex and for the analog bodies only of course.

Here a diagram of the diaphragm-block and a photo showing those 2 wheels and the sensor:



Last edited by photogem; 06-13-2019 at 01:29 AM.
04-11-2019, 08:32 AM   #297
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QuoteOriginally posted by photogem Quote
I try to explain it, but here my English is not good enough!
Google translator would be as critical as in this case so it is not always that easy.
thank you for the explanation, but I'm still not fully understanding, when I get some time I think I will re-read your explanation while looking at pictures of the aperture block or perhaps disassemble a camera. ( I have an istDS that needs some work )

I still find it puzzling that observing the lens iris while using Auto aperture I detect the iris closing fully during the cycle, I mistakenly thought this was at the beginning of the cycle but when observed at a large Av (.5 or 1 sec) clearly it is at the end of the cycle.

that is ... from fully open, the iris shuts to the selected aperture for the selected Tv, then briefly closes to minimum before opening fully again. So this is normal operation. I guess I'll not understand what part the solenoid plays in this and why pictures are dark when it fails without understanding the whole thing.
04-11-2019, 09:33 PM   #298
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Just my opinion of course, but I can not conceive of an exposure, of a properly functioning camera, causing the lens to stop down to minmum aperture and then back to whatever the properly metered aperture is. But you're saying it's the other way around, the lens is going to the proper aperture and then stopping down all the way before opening fully?


In any case I'll repeat, when you fully mount any Pentax lens, K or more recent, onto a Pentax camera, K1000 or later, the lens will be at full aperture for that lens. So if someone says to test a camera by looking at the lens to see if it opens up when you take the exposure doesn't make sense.

Last edited by Big Tim; 04-11-2019 at 09:41 PM.
04-11-2019, 11:33 PM   #299
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QuoteOriginally posted by Big Tim Quote
Just my opinion of course, but I can not conceive of an exposure, of a properly functioning camera, causing the lens to stop down to minmum aperture and then back to whatever the properly metered aperture is. But you're saying it's the other way around, the lens is going to the proper aperture and then stopping down all the way before opening fully?
yes, sorry I got this wrong in my first reply thinking that it was at the start of the exposure but it is immediately after the exposure that it closes (very quickly) before returning to wide open, this can be seen most clearly with a long exposure time, and adjusting the viewing angle to get a clear view. I don't think this means much, just part of the process (When I incorrectly thought it was at the beginning of the exposure I thought it may be significant).


QuoteOriginally posted by Big Tim Quote
In any case I'll repeat, when you fully mount any Pentax lens, K or more recent, onto a Pentax camera, K1000 or later, the lens will be at full aperture for that lens. So if someone says to test a camera by looking at the lens to see if it opens up when you take the exposure doesn't make sense.
yes its already wide open.
04-30-2019, 07:57 AM   #300
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QuoteOriginally posted by Not a Number Quote
One poster on the German forum said a Ricoh rep told him/her the K-30/50 were designed to last 4-5 years. I would hazard to guess this is the same for other consumer grade cameras like the K-S1, K-S2 and perhaps the K-70.
From the fantastic story - “Fragile, fragile, fragile world” (written in 1966):

“... everywhere is the universal principle of trade - fragile things are bought more often. Even if they buy cheap, but more and more often. Monthly, and then weekly, daily, hourly ... In the pocket of Ken Price it sounded loud. Then he squealed, creaked and hoarsely hoarsely. Disposable factory watches exploded. "When the factory ends, the clock explodes surprisingly melodiously." Promotional tales! Wow - melodic!
Fingers felt something like a lump of clay mucous ... Brr ... It
all that is left of the clock. The newest blitz metal, now many things are made of it, even cars. A special blitz-metal with a special structure turns into a trick in exactly two weeks ...
One-day things. Reliable, like a rope of dough. Long
like a piece of ice on a hot brazier. A handful of dust, a handful of smoke, no more. There were books with disappearing text - in a week there are white pages in front of you. Blackened newspapers that do not have time to read and are forced to buy the next hourly number. Quickly cooling irons and fusible pots. Perfume "Coco", starting with a week, stink. Blitz-metal nails. Paper TVs ...
Their cheapness does not compensate for their fragility. On the contrary, cheapness ruined the buyer. The carousel of forced purchases spun faster and faster, exhausting the soul, emptying the pockets ...
Elegant shoes with fast fading soles and stretching like the skin of a rotten banana. The collar of the day dress melted and ran down the back in thick drops. Lost wallet jumped out of pocket.
The leather belt suddenly burst. Ken Price ran, stumbling, supporting his pants with one hand. The world of fragile things mocked him ... "
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