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Forum: Pentax K-30 & K-50
02-26-2024, 05:56 AM
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I’m surprised people are still dealing with this issue. The KF - which costs under $1K - seems to have finally put it to rest, and in any case is a clearly superior camera.
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Forum: Pentax K-30 & K-50
04-02-2022, 08:37 PM
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Even with my K-30, it took two years for my body control of the aperture to fail;
I’m now hearing that the body-control of aperture on the K-70 works much better than it did on the K-30, so I expect you will find replacement solenoids to work better, and to take longer to fail.
Because of advice here, people who were doing it themselves mostly used ‘white’ solenoids harvested by themselves or by others, so you are asking for a less common result from a smaller ‘universe’.
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Forum: Pentax K-30 & K-50
11-11-2019, 08:32 AM
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The "resistor" and other 'electronics" are the result of mention in servicing reports by professionals. I will continue to mention them until you explain exactly how metering can be correct for LCD - but bad for OVF - as a result of a bad solenoid.
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Forum: Pentax K-30 & K-50
11-10-2019, 11:14 AM
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You are correct up to a point - my theory is that if you fix the solenoid so that your test will be passed - but there is still a problem with the resistor - the LCD will give good metering but the OVF still will not. That seems to be the lesson of several K-70 bodies recently sent in for repair which started off with bad OVF metering followed by bad metering from any source, and service replaced both the solenoid and the resistor.
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Forum: Pentax K-30 & K-50
05-29-2019, 12:05 PM
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The reason I asked about "Optical Preview" initially is that I believe it uses the exact same machinery to accomplish the exact same 'stop down' task that is usually the first step of taking a photo
1a. stop down lens
1b. move mirror out of the way
2. trip shutter & record image
3a. open up lens again
3b. return mirror
{the a. and b. steps may happen simultaneously; I listed them separately because they are done by different mechanisms, and listing them this way makes it easier to talk about them}
When I was using my K-30 regularly, I often would use Optical Preview to exercise the mechanism, to free it up without putting stress on the shutter.
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Forum: Pentax K-30 & K-50
04-25-2019, 10:04 AM
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So some other source of motion moves the aperture iris - to take a photo, for green button metering, or for 'Optical Preview' - the "only" role played by the solenoid is to limit that motion when opening is set from the body?
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Forum: Pentax K-30 & K-50
04-21-2019, 10:23 AM
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The solenoid is used to implement aperture opening set from the body, so it should be used anytime the lens doesn't have an aperture ring or when aperture ring is set to 'A'. With my K-30, now that the solenoid isn't working well at all, I use aperture ring to control aperture and then have to shoot in 'M' mode so I can use "green button" metering, and that works just fine despite the ailing solenoid.
added: my point being that if my K-30 works fine in 'M' mode but with aperture ring setting the aperture, I've been thinking that the solenoid isn't used in that setting, but I suppose the solenoid could just push as far as the lens would allow it to; I was hoping that someone would have definite information about solenoid use under that circumstance.
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Forum: Pentax K-30 & K-50
04-20-2019, 07:42 AM
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In 'M' mode, do you mean that the aperture ring is used to set aperture, or do you mean 'M' set on mode dial and aperture still set from the body?
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Forum: Pentax K-30 & K-50
04-18-2019, 09:32 PM
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Getting back to basics: according to your experience, under what circumstances will the solenoid not move at all when trying to adjust the aperture? {taking photo or "optical preview"}?
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Forum: Pentax K-30 & K-50
04-16-2019, 12:36 PM
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@photogem; understands the details in a way I don't - so he may have to address the details. Are you saying that the solenoid doesn't move at all or that the aperture doesn't move at all or that neither moves at all? If the camera is operating correctly, the lens should be open to its widest aperture before you press the shutter button, then close down to the requested opening when you press the shutter. When using a lens with aperture ring, the lens stops the closing when it reaches the requested opening; when using a lens without aperture ring, the solenoid stops the closing when it reaches the requested opening {so if the solenoid isn't working correctly, the lens closes all the way to its narrowest}. If the aperture is set to an intermediate opening {between widest and narrowest}, and the aperture isn't moving at all, that would say to me that something else may broken - or else that the solenoid is jammed in the narrowest opening setting; one way to test this is to check behavior with a lens that has an aperture ring so you could manually try both "al the way open" and "all the way closed".
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Forum: Pentax K-30 & K-50
04-14-2019, 12:06 PM
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Your experience doesn't make any sense to me
Since the LV at 1/50 gives a good photo, but using viewfinder at 1/2500 gives dark results, I would say that the meter in the prism housing is faulty. Having K200 {1/3000} and K-50 {1/2500} viewfinder settings be very close - but results be completely different - makes no sense at all.
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Forum: Pentax K-30 & K-50
04-11-2019, 07:29 PM
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So you took three photos of the same scene using the same lens?
(1) K-50 LV: ISO=400 aperture f/2.8, shutter 1/50
(2) K-50 viewfinder: ISO=400 aperture f/2.8, shutter 1/2500
(3) K200 viewfinder: ISO=400 aperture f/2.8 shutter 1/3000
What did the three photos look like?
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Forum: Pentax K-30 & K-50
04-11-2019, 11:57 AM
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There are several reports here of cases where LV and viewfinder exposure differ, such as
K30 Liveview Vs Viewfinder Differences - PentaxForums.com
Member @RedSky sent his in for repair - they did the standard repair for aperture control issue ..... and it still didn't work right
TWO K-50s giving me the same error !!! Pentax is no help. HELP!! - PentaxForums.com
I believe that some of these cameras have a different issue .... one involving metering {light is measured differently when you take an LV photo as compared to when you take a photo using the viewfinder}. @RedSky got the usual 'help' here - everyone thinks of aperture control first, second, and third, but not all exposure issues are due to that problem - and eventually left in frustration. That is why I suggest that people use a very constrained approach - fixed ISO with Av mode - and record the shutter speed requested in LV and in viewfinder mode. If the shutter speed requested is significantly different, then it is actually a metering problem.
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Forum: Pentax K-30 & K-50
04-10-2019, 01:04 PM
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Exposure problems are harder to trace down when auto ISO - because ISO can change from exposure to exposure, so it is harder to compare shots.
What I would do if I were you is to take one photo using viewfinder and Av mode.
Take a similar photo using LV and not changing anything else from previous one.
Without editing either photo, post both here so we can see what you are seeing.
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Forum: Pentax K-30 & K-50
04-10-2019, 08:25 AM
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Which mode are you using - 'P', 'Tv', 'Av', 'TAv', .....
What ISO setting are you using - hopefully not 'auto'?
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Forum: Pentax K-30 & K-50
04-10-2019, 08:22 AM
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How would an aperture problem cause photo taken using OVF to be darker than photo taken using LV?
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Forum: Pentax K-30 & K-50
04-09-2019, 01:06 PM
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There is some evidence of metering issues - which have been misdiagnosed as aperture control issues (*). If you get different results depending on whether you use viewfinder or LV, that would be something to investigate. Can you use Exposure Compensation { +/- button } to bring results to within reasonable?
(*) One guy apparently gave up when he didn't get any help here - or from Pentax Repair {they replaced the aperture control unit, and announced it "fixed" .... but it still didn't work right}
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Forum: Pentax K-30 & K-50
03-15-2019, 09:59 AM
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If this "fix" may have caused issues, have you gone back to the place where you originally posted this photo to warn people?
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Forum: Pentax K-30 & K-50
03-11-2019, 11:44 AM
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I'm glad this worked out for you. One user managed to ruin his camera by accidentally apparently discharging stored charge through the processor
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Forum: Pentax K-30 & K-50
03-10-2019, 05:24 PM
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There is no reason to believe that anyone still manufactures a solenoid with the exact characteristics of the 'white' solenoid, which is the reason for a "treasure hunt" amongst old Pentax cameras and similar electronics.
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Forum: Pentax K-30 & K-50
03-10-2019, 02:41 PM
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Yes, they say they took these from genuine Pentax cameras.
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Forum: Pentax K-30 & K-50
02-22-2019, 05:54 AM
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This is one of the problems in using a 'stock' part ..... their definition of "improve" may be different than yours ..... and I'm guessing Pentax got no notice at all of any changes to "appearances and specifications".
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Forum: Pentax K-30 & K-50
02-21-2019, 04:43 PM
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Pentax doesn't commission parts like this. They use a generic part out of a catalog. In fact. that is part of the problem - the producer changed how they construct the part, apparently without telling Pentax or even changing the number; Pentax kept their same numbers, so they had no realization that anything had changed, nor do they have any way to trace back in their database. And, yes, users who do solenoid transplants sometimes go to old CD devices to get an appropriate solenoid.
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Forum: Pentax K-30 & K-50
02-18-2019, 07:37 AM
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Anyone who disagrees with his research seems to antagonizes him - don't take it personally.
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Forum: Pentax K-30 & K-50
11-20-2018, 11:42 AM
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The important difference is in how they "age". Are you thinking breaking force would affect that somehow??
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