[FotoGekko]

A 'defect' K50 18-135 combo is offered here for a fairly attractive price (€180)
I started reading assuming it would be an aperture block problem, but seller describes it as follows:
The camera is perfect from the outside and shutter count is only 5700. However there are both autofocus and exposure issues; sometimes pictures turn out unsharp or over exposed and then again they are OK.
I know this is a difficult question, but am impressed of course over and over again by the expertise on the forum
So, any suggestions what the problem could be from this scarce info?
(Unfortunately seller is not really close, by European standards that is)

Thanks in advance for any suggestions! Gerard

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Last edited by FotoGekko; 04-22-2021 at 06:00 AM.

[HoutHans]

I have no idea what this can be. It could just be user error (accidentally switching to MF or pressing another button). If you have manual lenses, just buy it and the autofocus failure shouldn't matter at all. Not sure how that would solve the exposure problem, but this is also due to the fact that I'm unsure about the nature or cause of that problem.

[MoRoTAS]

A 'defect' K50 18-135 combo is offered here for a fairly attractive price (€180)
I started reading assuming it would be an aperture block problem, but seller describes it as follows:
The camera is perfect from the outside and shutter count is only 5700. However there are both autofocus and exposure issues; sometimes pictures turn out unsharp or over exposed and then again they are OK.
I know this is a difficult question, but am impressed of course over and over again by the expertise on the forum
So, any suggestions what the problem could be from this scarce info?
(Unfortunately seller is nog really close, by European standards that is)

Thanks in advance for any suggestions! Gerard

The aperture solenoid is most likely failing. My K50 was intermittent at first and then became a manual focus/aperture camera only. It had about the same shutter count, as I remember.

[othar]

overexposure could be caused by a stiff aperture (wide open / or close wouldn't be a problem but the further stopped down the bigger the discrepancies).
The focus issue doesn't really sound like one, because it isn't consistent. My guess would be user error, maybe a combination of slow shutter speed and unstable camera position or unrealistic expectations in low contrast situations. Of course I don't know the guy so I could be totally wrong (maybe ask for an unsharp image to check his exif data? )

[othar]

The aperture solenoid is most likely failing. My K50 was intermittent at first and then became a manual focus/aperture camera only. It had about the same shutter count, as I remember.

Wouldn't the solenoid failure lead to underexposed pictures?

[FotoGekko]

Right, that's why I doubted the solenoid failure. When my K30 failed it started intermittently, but with underexposures. It did occur to me that the guy is inexperienced, also the way he described the failures, thus causing one or more of the problems. It could of course be the lens, though failures with the 18-135 are rare I gather.
However the amount asked is just a bit on the high end to take a plunge without prior knowledge.

Cheers Gerard

[othar]

Right, that's why I doubted the solenoid failure. When my K30 failed it started intermittently, but with underexposures. It did occur to me that the guy is inexperienced, also the way he described the failures, thus causing one or more of the problems. It could of course be the lens, though failures with the 18-135 are rare I gather.
However the amount asked is just a bit on the high end to take a plunge without prior knowledge.

Cheers Gerard

On the bright side, it is very unlikely that both (camera + lens) are faulty, so depending on which you are more interested in it could still be a tempting offer

[reduno]

However there are both autofocus and exposure issues; sometimes pictures turn out unsharp or over exposed and then again they are OK.

Did the seller indicate if the issues were only seen using the optical viewfinder or in live-view as well? I agree that it is unlikely both the lens and camera are faulty, so depending on the shipping costs and import duties (it any within Europe) it may still be worth it, especially if the seller will accept a lower offer.

[c.a.m]

Thanks in advance for any suggestions! Gerard

I generally avoid the temptation to buy potentially faulty items, even if the price is attractive.

The problem with this camera is difficult to assess based on the limited description from the seller. Assuming that the seller is the original owner, they have had quite a lot of experience with the camera, at 5,700 shots, so I would think they are familiar with its operation. It is unlikely that both the camera and lens are faulty, unless they have been dropped and suffered physical damage, which is possible.

I guess the question is: Would you be comfortable buying the camera and lens and losing 180 Euros?

- Craig

[ChristianRock]

My K-50 has overexposure issues every now and then (depending on the lens) but it's probably not related to what this camera is experiencing.

Mine overexposes because the shutter stays stuck open sometimes. Then pressing the shutter button again closes it. Then the next few shots, it doesn't do that. It annoyed the previous owner enough that I was given the camera for free... but strangely, there's lenses, especially manual lenses, where it does not happen. It also seems to happen when there's a lot of humidity in the air, and not when the air is dry...

And my K10D's buttons also sometimes "push themselves" without me touching them - especially the "Protect Images?" option seems to call itself a lot when I'm in image view mode. I think it's a main board issue, not worth fixing....

The reason I'm saying this is, cameras can develop issues other than aperture block failure, and this K-50 in the ad probably is suffering from those electronic issues.

[AfterPentax Mark II]

And perhaps it is just a case of a good clean of the contacts. It can be all sorts of problems from difficult to easy solution.

[ChristianRock]

It could also be a slow iris on the lens... it would be interesting to find out if it happens with other lenses as well.

[pentaxus]

The camera sounds way too scary to me.

[FotoGekko]

Thanks for all the feedback, appreciated!
I decided to let it go, was considering it as a hobby project (repair and sell on) anyway, I already posses a K30 (self repaired) & 18-135. Should the camera be defect I'd have a hard time selling the 18-135 at a profit in the current market. Just a pity that seller lives to far away, still curious.
Thanks again, cheers,

Gerard

[photogem]

A 'defect' K50 18-135 combo is offered here for a fairly attractive price (€180)
I started reading assuming it would be an aperture block problem, but seller describes it as follows:
The camera is perfect from the outside and shutter count is only 5700. However there are both autofocus and exposure issues; sometimes pictures turn out unsharp or over exposed and then again they are OK.
I know this is a difficult question, but am impressed of course over and over again by the expertise on the forum
So, any suggestions what the problem could be from this scarce info?
(Unfortunately seller is not really close, by European standards that is)

Thanks in advance for any suggestions! Gerard

Don't you have another Pentax body to check the lens by itself?


That the K50 sometimes delivers over-exposed photos could well be because the solenoid was filed/sanded.
A common issue.

But not focusing correctly could be
- the lens (so to check it with another Pentax)
- more having been messed up during a possible solenoid modification/sanding.

Repairing/modifying the solenoid would normally not mess up AF. Not interlinked at all.

So of course I would check the K50 with another AF lens as well.