[detour]

I think we have to wait what our new member comes up with.
Problem is, that some ask a question, members answer (or pretend to answer) but then there is zero reply, such as with this one:
DA 50mm 1.8 aperture stuck after drop - PentaxForums.com

First of all, thank you so much for the help! I‘m so sorry for the late reply. This weekend I tried it again and the problem sitll remained. I believe I should take more shots and provide more examples. I'll get back to it soon. I think the solenoid problem you mentioned is very likely to me the cause. If it is true, I might have to abandon this K-50 and try another PENTAX machine...cause there is nowhere to get it reparied in the city.

---------- Post added 08-16-20 at 19:40 ----------

That's some weird firmware display for a K-50. That aside, your problem might be aperture block related. It could also be the exposure sensor at the bottom of the mirror box housing. The lens you were using... did it have an aperture ring, or was it fully automatic, or a PLM lens? If it had an aperture ring, then it would make sense for the exposure to be fine using manual mode if the lens isn't set to Auto or A. If it's something like the 18-55 kit lens, then all images would have been dark with aperture block issue unless the aperture solenoid temporarily worked after several shots.

More testing should be done, especially after the camera has been sitting for a while.

here's a link to the aperture block thread: Dark exposure problems on K-30 or K-50? Read me first! - PentaxForums.com

The lens you were using... did it have an aperture ring, or was it fully automatic, or a PLM lens?

I tried DAL 18-55 kit and A 50mm 1.7(ring points to "A"; can adjust on the camera). Same outcomes.

---------- Post added 08-16-20 at 19:43 ----------

From your photos, there's around a four-stop difference in exposure between the LV and viewfinder shots (AV) - shutter speed 1/6 rather than 1/125 - which is possibly why the auto and AV viewfinder shots look dark. Same exposure in viewfinder manual as in LV (1/6 second) which is why that one looks ok. We'd need to know exactly which lenses you were using to try to help further, I think.

Thank you! I agree with that. I will try to get more examples back to this thread soon!

[photogem]

First of all, thank you so much for the help! I‘m so sorry for the late reply. This weekend I tried it again and the problem sitll remained. I believe I should take more shots and provide more examples. I'll get back to it soon. I think the solenoid problem you mentioned is very likely to me the cause. If it is true, I might have to abandon this K-50 and try another PENTAX machine...cause there is nowhere to get it reparied in the city.

No need to take more shots or provide samples!
It depends now, do you use your lenses in AUTO or Scene-Mode (SCN) or do you understand Tv and particular AV?
If you understand AV, then just take some photos wide open (with your SMC Pentax A50/1,7 you set the A-Ring on A
and then f=1,7..... etc): Photo should be totally underexposed, very dark, almost black


If you only use AUTO or SCN Modes, then

check the liveview option described here:


Detection of aperture block/diaphragm-block failure/stuck solenoid K-30, K-50, K500 - PentaxForums.com
If your SMC A50/1,7 closes completly instead of remaining about half open (f4,0) then it is 100% certain at that moment you look into the front of the lens and at this moment all the blades /diaphragm closes to this tiny hole when you switch LiveView on.

[Praktica*ist]

Hello.
Well, this is an aperture block failure case, again...

You have a Pentax-A 50mm f/1.7 ? So you will still be able to take photos on manual mode, by one at a time light metering, using the green button. You will have to rely on your aperture ring on the lens. This is your best option before having the K50 repaired.

What currently happens, when you have the dreaded K-30 / K-50 aperture block failure, is an uncontrollable aperture condition : the camera always releases the aperture lever of the lens fully. This causes the aperture to be closed at his maximum, no matter what value you set **on the camera**. The way to avoid the problem is to have a lens with aperture ring at hand. In this case, the closing aperture value is set directly by the lens ring, and it does not matter that the camera releases the lever fully. If your lens is set to f/5.6 you will get that value, and not f/22 - f/32 unlike on a fully automatic lens.

[photogem]

What do you mean with "the camera always releases the aperture lever of the lens FULLY"?
I guess this could be a language problem.

Wide open (1,7 for the A50/1,7) ?

or


fully closed (22 for the A50/1,7) ?

[Praktica*ist]

It is fully closed.



On a K mount, with the lens set to "A" or a fully automatic lens like the 18-55mm kit lens, the resting position of the aperture lever is fully closed.
It is the case when the lens in not mounted on the camera. It is spring loaded.
When you mount the lens on a camera, the aperture control lever of the camera engages and moves the lens aperture lever : the lens aperture is now fully opened.


What should happen (on a good working camera) when you take a photo, is an aperture control lever that moves the exact displacement in millimetres to make your lens close at, say f/5.6.
It is a displacement proportional to the desired aperture value.

On a K-30 / K-50 etc... that has an aperture block failure (solenoid problem), the control lever does not stop to the right position, it goes full travel, letting the spring inside the lens fully close the aperture (f/22 or f/32 depending on the lens).

[photogem]

O.k. I understand what you mean!

But:

On a K-30 / K-50 etc... that has an aperture block failure (solenoid problem), the control lever does not stop to the right position, it goes full travel, letting the spring inside the lens fully close the aperture (f/22 or f/32 depending on the lens).

This is not quite how it works.

The solenoid not yet actuated has the plunger in "pull-position" (drawn in by the magnet) which is the fully closed position for the lens.

If all is fine and thus the plunger can "push" out (the two electro-magnets counteract the force of the permanent magnet, anull it), it releases to that aperture which was measured to be correct during metering (Av, Tv, Tav, P Modes).

But if the plunger is stuck (because the plunger, sitting all the time when not in use near the magnet, gets magneticed* and due to other factors often explained in this forum) it cannot release. So the aperture stays just fully closed instead of opening to the desired/measured value.

I have tried to explain it in this post:
Dark exposure problems on K-30 or K-50? Discussion Thread - Page 20 - PentaxForums.com

[detour]

Hello.
Well, this is an aperture block failure case, again...

You have a Pentax-A 50mm f/1.7 ? So you will still be able to take photos on manual mode, by one at a time light metering, using the green button. You will have to rely on your aperture ring on the lens. This is your best option before having the K50 repaired.

Absoluetly right! Last weekend I did take the len with me on the journey to my hometown and everything works well! Now I'll send my K50 to get repaired! Thank you!

---------- Post added 08-29-20 at 15:12 ----------

No need to take more shots or provide samples!
It depends now, do you use your lenses in AUTO or Scene-Mode (SCN) or do you understand Tv and particular AV?
If you understand AV, then just take some photos wide open (with your SMC Pentax A50/1,7 you set the A-Ring on A
and then f=1,7..... etc): Photo should be totally underexposed, very dark, almost black


If you only use AUTO or SCN Modes, then

check the liveview option described here:


Detection of aperture block/diaphragm-block failure/stuck solenoid K-30, K-50, K500 - PentaxForums.com
If your SMC A50/1,7 closes completly instead of remaining about half open (f4,0) then it is 100% certain at that moment you look into the front of the lens and at this moment all the blades /diaphragm closes to this tiny hole when you switch LiveView on.

Hi, photogem. I'd tried what you say in your thread and it appeared the same way. After that I search "K50 aperture issue" on TAOBAO (Chinese biggest online shopping mall) and confirmed that. Thank you!

[photogem]

@detour:
if you send in your Pentax K50, they will just replace the green solenoid.
Nothing personal but it just is 100% facts that the made in China solenoid is not as good anymore than the original made in Japan solenoid!
You can repair your K50 yourself:
Manual solenoid replacement Pentax K30 / Discharge flash-condenser / Solenoid choice - PentaxForums.com

[reh321]

Absolutely right! Last weekend I did take the lens with me on the journey to my hometown and everything works well! Now I'll send my K50 to get repaired! Thank you!

As you have demonstrated, there is more than one solution to this issue.
Photogem prefers to do surgery himself; for those of us less skill in manual work, I suggest just continuing to use lenses where you can use the aperture-ring and 'green-button' metering.
You do lose the power of 'TAv' mode - but that is not much of a loss with the K-50; I can adjust from "green button" metering - which uses same sensor as automatic metering.
You get to choose - don't let anyone take that decision away from you - all we should do is tell you what choices you have and the result of each choice.

[photogem]

As you have demonstrated, there is more than one solution to this issue.
Photogem prefers to do surgery himself; for those of us less skill in manual work, I suggest just continuing to use lenses where you can use the aperture-ring and 'green-button' metering.
You do lose the power of 'TAv' mode - but that is not much of a loss with the K-50.

This is wrong: One doesn't just lose TAv-mode but one loses TA, TAv, Tv, Sv, P.... AUTO+SCN and all User-modes if the solenoid stops working!
One also loses Live-View!

One loses all Semi-Auto Modes and is stuck with M-Mode and the by its nature not so precise method of green-button-metering.
(I myself am happy for green-button-metering, I still use many manual lenses, but particular for those with glasses but good enough eyes for exact diopter adjestment it can be quite time consuming and thus losing the chance for a quick shot, if one has to take glases down to see what is on the screen.)

Also: This suggestion of yours was already given to him, so I don't understand why you bring it up with what seems to me a kind of attack:
You get to choose - don't let anyone take that decision away from you - all we should do is tell you what choices you have and the result of each choice.

Who tries to take that decision away from the threadopener? This sounds as if this is some kind of competition or business? Sounds very strange to me!

We try to help and give sensible suggestions.

The suggestion of exchanging the solenoid isn't "surgery" but it is a now by me I think well documented DIY repair many successfully applied.
Anybody not up to soldering or opening a body will not apply it so I really don't understand this comment of yours!

Particular also because of the loss of Live-View function:

LV together with Focus-Peak ON is a very useful instrument for manual shooting.
To lose LV reduces the K30/50/50/70/S-1/S-2 imho to something I find very boring. I would not use a defunct K30/50 etc. for just minimalism.

If I want a perfect Pentax for manual lenses but only view-finder shooting then I'd still prefer my K5 with Katzeye split-image focusing screen.
Next to a K10D because of its CCD-Sensor, those are still great Pentax bodies.
If I can afford it, then a K3 with Katzeye + LV is of course a great choice.

Or.... of course a fully functioning K30/50 because it has LV + Focus Peaking!

If one finds a damaged *ist, K100D up to a K-r + K10D/K20D + Samsung equivalens one can find the solenoid very cheap, in all *ist, K100/200 bodies even 2 white solenoids! For about $ 30 one uses one solenoid for oneself, the other one can be sold, so it's actually free! I do the repair in 20minutes, my first one was 1 hour.
Some need longer. And it almost never went wrong (I'd say 98% of all who dare manage it well)

And if one has a working *ist, K100D, K110D or K200D, one takes the solenoid out of the flash circuit and exchanges it with the green one because the green one works fine there, is not stressed, the mechanism is much more simple.
So one can actually get it for free!

[Not a Number]

Just a reminder folks: Discussion which at times may become heated can remain friendly without resorting to harsh and insulting comments.

See also:
An important message from the moderators - PentaxForums.com