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Forum: Pentax K-S1 & K-S2
08-30-2020, 12:59 PM
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The issue is not the PLM motor; the issue is that the 55-300mm PLM lens is a "KAF4" lens. This latest variant of the K-mount sends electronic messages to the lens, and electronics / motor within the lens control the aperture; only recent cameras can send the needed commands to the lens. Older K-mount lenses use mechanical linkages to move the aperture; the solenoid in question causes the linkages to move properly. The earliest Pentax lenses - "Takumar", "Pentax", and "Pentax-M" lenses - lack the ability for the body to control the aperture, so the user has to control the aperture via the aperture ring.
A similar process is involved in controlling auto-focus. Older lenses control AF through use of a motor within the camera which drives the "screw-drive" which conveys motion to the lens; in more recent lenses, signals are sent to a motor {such as the "PLM" motor} within the lens.
https://www.pentaxforums.com/articles/photo-articles/evolution-of-pentax-k-mount.html |
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Forum: Pentax K-S1 & K-S2
12-08-2019, 08:22 PM
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I am sorry to hear that your problem has re-occurred.
To answer the question you now ask, the K-70 is the only currently manufactured camera which has solenoid-powered body aperture-control like the K-S2 does. Personally, when my K-30 started to 'reliably' fail, I got an FA 28-105 lens and continued under lens-ring control of the aperture. Today I am using a KP, which has the same {stepper motor powered} body aperture-control as the K-3 family does. MarkJering is correct that the "white" solenoid seems to last, unlike the "green" one, so if you are physically capable, doing your own substitution is also an option.
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Forum: Pentax K-S1 & K-S2
06-23-2019, 09:15 AM
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Remember that every camera is different. Evidence is that the average K-S2 body will give many years of good service and never have aperture control issues of any sort.
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Forum: Pentax K-S1 & K-S2
06-16-2019, 09:06 AM
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A thread in the K-70 area is very relevant here.
Solenoid in Pentax K-70 - PentaxForums.com
Member @photogem; compared the solenoid used in the K-30/50 with the one used in the K-70 {and presumably in the K-S2}
The following summarizes his conclusions
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Forum: Pentax K-S1 & K-S2
06-15-2019, 08:41 AM
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'We' do not understand the process of one of these cameras failing. Anecdotally, many stories of failure begin something like "I took my K-50 off the shelf where it had sat for six months to take photos of my child's First Communion and the photos were all dark". I was trying to encapsulate that sort of thought.
On the other hand, I purchased my K-30 from KEH at a time when I had never heard of the Dark Image Syndrome. My camera had a shutter count of 3 when I got it; I used it for about three years on AA batteries before it started failing. I am sure that a New In Box K-S2 purchased in June 2018 will be no more failure prone than it would have been when purchased the day after it was produced, but I would make a point of using it regularly after that.
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Forum: Pentax K-S1 & K-S2
06-13-2019, 06:27 PM
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Experience seems to show that the camera is less likely to have the Dark Image Syndrome problem if you use it regularly. Sitting on the shelf for a year is deadly for it.
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Forum: Pentax K-S1 & K-S2
06-13-2019, 06:21 PM
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In my case, I purchased an FA 28-105. It has an aperture ring, so it provides AF and meters in green button mode, which is similar to the manual-focus ME/SE {with the equivalent of Av and Manual modes} which started me down the Pentax path forty years ago. Even though I have a KP now, I still use the K-30 regularly, the most recent time being on Monday.
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Forum: Pentax K-S1 & K-S2
06-13-2019, 06:10 PM
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An additional comment:
In 1979 I purchased my first SLR - a Pentax ME/SE. Unfortunately I didn't properly protect that camera from the spray when we were at Niagara Falls, and in 1983 I suddenly needed another camera; I had been very satisfied with the ME/SE, but now the Pentax camera for sale at my local store was a "Super Program" {apparently called the "Super A" in some markets} , so I purchased that camera (*). According to research I've done recently, this was the very first camera to provide the KA-mount, and the mechanism which allowed the body to control the lens's aperture looks essentially like the mechanism used by my K-30 .... the last time I used it {last Fall} the aperture control mechanism still worked! 35-1/2 years old and the aperture control mechanism still works correctly - I would say that is a good design!
I am quite certain that the Pentax engineers were more confused than we were when reports first started coming in of this mechanism, which they had depended on for over 1/3-rd century, failing. I am disappointed that my K-30 has not worked perfectly for even 1/21-st century (1/7-th as long as the Super Program}, but that is not Pentax's fault.
(*) leftmost camera in my signature
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Forum: Pentax K-S1 & K-S2
03-11-2019, 08:32 AM
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Yes, most likely it will get worse. My K-30 starting exhibiting those symptoms in May 2018; by October 2018 it was consistently happening unless I was using half-charged AA batteries, so I switched it to a bag with several aperture-ring only lenses, and when I got a KP I moved it to the original collection of lenses. I try to use the K-30 at least once a month, and it still works fine with the aperture-ring lenses.
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Forum: Pentax K-S1 & K-S2
01-30-2019, 03:09 PM
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and the solenoid on the board is green???
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Forum: Pentax K-S1 & K-S2
01-28-2019, 01:03 PM
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So, they are selling used green solenoids???
I expect white solenoids to be used, that seems to be the only way they come these days, but green come new.
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Forum: Pentax K-S1 & K-S2
01-19-2019, 10:26 AM
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I used Canon 1995-2015. My first two DSLRs were Canon Rebels - each developed processor issues shortly after the warranty ran out, and each eventually died. After the second one died, I switched back to Pentax, so I cannot totally argue with your first line, (*) but I did so partly because of features such as IBIS and WR. Part of the lesson is that every manufacturer has issues, especially with the consumer-level cameras.
(*) to be quite honest, if Pentax were to stop making new cameras and I were to need a new one, I would probably purchase a Canon EOS-M {I'm not permanently mad at them}
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Forum: Pentax K-S1 & K-S2
01-15-2019, 10:30 AM
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Have you actually examined it to insure that aperture control unit is indeed failing?
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Forum: Pentax K-S1 & K-S2
12-26-2018, 04:12 PM
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The aperture control issue appears to be much less common on the K-S2. It is most common on the K-30/50. Experience with the K-30/50 was that calendar time {typically over two years} seemed to be more important than shot count, and the problem often hit cameras that had been idle for awhile (*), so forcing yourself to use your K-S2 on occasion (**) may be the best way of avoiding the issue.
(*) Often someone would report something like "I last used my K-50 for Christmas snapshots; when I took it off the shelf to record my son's first steps four months later, it failed me".
(**) Just for "old times sake" I used my K-30 to photograph our Christmas tree. After finding four usable AA-batteries, it felt so awkward just a month after it was my regular camera .... I can see why someone would just use the KP for everything.
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Forum: Pentax K-S1 & K-S2
12-21-2018, 07:04 PM
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This problem often takes two or three years to develop.
I'm guessing Receiving Inspection of parts doesn't do much to separate 'good' from 'bad'.
'Good' and 'bad' parts all we assigned the same part number in their system.
The usual tools for addressing problems of this kind would be of limited value.
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Forum: Pentax K-S1 & K-S2
12-19-2018, 08:34 AM
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Where did you send it off to?
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Forum: Pentax K-S1 & K-S2
08-11-2018, 06:44 AM
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Did you read
How to use/meter Manual & M42 Lenses on all Pentax DSLRs (K-1, K-3, K-5, K-30, etc) - PentaxForums.com
Second line is "if you're wondering whether or not these lenses can be used with Pentax DSLRs (or the K-01), then the answer is yes! Pentax as well as third-party manual and screwmount lenses can easily be mounted on any Pentax DSLR (such as the K-1, KP, K-3, K-70, K-S2, K-S1, K-50, K-500, K-30, K-5 series, K-r, K-x, K-7, K10D, K100D, K200D, *ist D, etc.) Just follow this guide!" {emphasis added by me}
I won't say any more if you're convinced that you know something Adam doesn't know
"
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Forum: Pentax K-S1 & K-S2
08-10-2018, 10:25 AM
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Did you read the article I pointed you to???
How to use/meter Manual & M42 Lenses on all Pentax DSLRs (K-1, K-3, K-5, K-30, etc) - PentaxForums.com
On my K-30, and I believe all the Pentax cameras are like that, once the aperture ring is in the "A" position, the aperture is controlled just as it is for any lens without the aperture ring - by the camera body when in 'Tv' or 'P' mode, or by you using the aperture ring when in 'M' mode. Only in the latter case do you have to deal with the "complexities" of "green button mode".
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Forum: Pentax K-S1 & K-S2
08-07-2018, 01:18 PM
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Forum: Pentax K-S1 & K-S2
07-31-2018, 08:59 PM
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This brings us back to discussions about the K-70. I keep hearing that Pentax has surmounted the aperture control issue for the K-70, but I'm not sure what kind of testing can assure that, because time seems to be more of an issue than usage. I'm also fairly certain that everything you say about the K-S2 is also true of the K-70; the K-70 hasn't been out long enough and only so many have been sold.
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Forum: Pentax K-S1 & K-S2
07-01-2018, 05:15 AM
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People are good about spreading Fear Uncertainty Doubt, but it is just FUD here. There are very few reports of this issue with the K-S2.
The main advice I can offer is to use it - don't let it sit at the back of a closet shelf for months at a time
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Forum: Pentax K-S1 & K-S2
06-28-2018, 03:31 PM
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This "My camera was unused for a while and now it has aperture control problems" seems to be a very common story.
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Forum: Pentax K-S1 & K-S2
06-14-2018, 01:19 PM
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I purchased a Canon Rebel in which the processor started having problems after 12 months and totally failed after 18months.
I have had the K-30 for 37 months now {over twice the total lifetime of the Rebel}; aperture problems seem to be starting now. Even now, it is much less "temporary" than the Canon was - especially since the aperture-ring lenses I have are AF, so the only cost of using them is pressing the {infamous} green button, which is no bother at all.
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Forum: Pentax K-S1 & K-S2
06-14-2018, 09:37 AM
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When you say "temporarily" do you mean that you expect it to stop working, or you think you could tolerate that only so long?
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Forum: Pentax K-S1 & K-S2
06-13-2018, 10:31 AM
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The other "solution" is to use lenses equipped with aperture ring.
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