K-30 dark shots


Nickbat

Link Posted 10/05/2016 - 16:56
Hi,

I read the other post about the dark pictures on the K50 with interest as I have a similar 'problem' with my K-30. If I use LV, everything is fine, but if I shoot looking through the eyepiece, the picture comes out black.

I assume that my problem is also a faulty motor, but being a tad dim when it comes to DSLRs, it could be an operator fault! Any advice?

Thanks

Nick

Nickbat

Link Posted 10/05/2016 - 19:26
I've been reading up on the web and it looks like the dreaded diaphragm control block that's died. If only I had learned about this apparently common fault on the K-30s before I bought it 19 months ago.

Looks like it is headed for the bin, as I would imagine the cost of repair will be prohibitive. Any ideas as to how much a repair would be?

Nickbat

Link Posted 10/05/2016 - 19:59
I've cleared the problem for now with some hi-speed burst shooting. However, I don't trust it now....

Mag07

Link Posted 10/05/2016 - 20:48
19 months ago....that's still under warranty in the EU if that's where you are ofc
'Photography...it remembers little things, long after you have forgotten....' (Aaron Siskind)

Nickbat

Link Posted 10/05/2016 - 21:15
Actually I just found the receipt and it was purchased 21 months ago from Jessops in the UK.

However, while Canon offer a 2-year warranty, a visit to the RICOH site states "All PENTAX cameras purchased through authorised bona fide photographic distribution channels are guaranteed against defects of material or workmanship for a period of twelve months from date of purchase."
Last Edited by Nickbat on 10/05/2016 - 21:19

InFESTation

Link Posted 10/05/2016 - 21:43
May help in where to start

http://www.which.co.uk/consumer-rights/regulation/sale-of-goods-act
Pint o' rough & a game o' darts anyone

richandfleur

Link Posted 10/05/2016 - 21:44
Hi,

Having been right through the fault and repair process myself, I would highly recommend getting this dealt to ASAP if it is still under warranty. Contact the service provider and ensure you commence discussions before your warranty runs out etc.

The confirmation test from my perspective is to use a lens with a manual aperture ring, so that you can set the aperture manually (usually any older K mount lens for example). The problem affects the cameras ability to drive the lens aperture to it's correct value, which affects shooting and metering, leading to under or over exposed shots.

Using a manual aperture lens allows you fix the correct aperture, and removes this task from the camera. So your camera shouldn't go in the bin, but it can't meter/adjust to the correct aperture anymore.

As I've said before, in my opinion this should have had an outright recall/free replacement for the reasonable life expectancy of the camera, say 5 years? If these had all failed at once there would have been an uproar, but Pentax have let it slide because they are failing at random intervals over time. Mine has had the replacement and worked flawlessly ever since, but I'll never know if they replaced it with another time bomb. I've heard of this part failing on K-50s also, essentially the same camera, but much less about the K-S series. Hopefully they have learnt from here, but that's little consolation for those affected right now.

Nickbat

Link Posted 10/05/2016 - 22:21
Thanks for that, richandfleur.

I''l try the confirmation test you suggested.

"Mine has had the replacement and worked flawlessly ever since..."

Was that done under warranty or did you pay? If the latter, what was the cost?
Last Edited by Nickbat on 10/05/2016 - 22:22

richandfleur

Link Posted 10/05/2016 - 23:33
Mine was just under warranty luckily.

Sounds stupid to say I'm glad mine failed so early, but in this case I was.

Definitely not what you'd expect from a new camera, and these have been failing from 1 1/2 years through to 3+ years later.

Hopefully you have access to a lens with manual aperture ring, as this is something that's commonly been dropped on plastic lenses in recent years to save money.

Nickbat

Link Posted 11/05/2016 - 19:09
Right, so I checked with an old lens and, sure enough it works properly, so it's looking increasingly certain that the diaphragm control block has gone. It has been confirmed that Pentax/Ricoh only offer a 1-year guarantee, so I'll need to think about whether a repair is worthwhile. The other option is to keep the K-30 with a manual lens (say a wide angle for scenery shots) and get a new DSLR for my recently-acquired Pentax 55-300 F4-5.8 zoom. Decision time is looming methinks.

One thing bugs me, though, and that is I cannot understand why the K-30 operates normally in Live View and yet under-exposes when shooting through the viewfinder. Can someone explain why this should be?
Last Edited by Nickbat on 11/05/2016 - 19:10

richandfleur

Link Posted 11/05/2016 - 21:58
Nickbat wrote:

One thing bugs me, though, and that is I cannot understand why the K-30 operates normally in Live View and yet under-exposes when shooting through the viewfinder. Can someone explain why this should be?

Others with knowledge on the metering process will be able to help here, but it was my experience that when the aperture motor failed, the lens did not return to the correct aperture after taking the photo. The camera would then meter for the next shot and be presented with more light coming in that it should have had. It would then select a much faster shutter speed than was really necessary, which would result in a severely underexposed shot which appears as all black/dark.

I did a video long ago to send to the repair people, which I wish I hadn't deleted now. I took a video of the front of the lens as I took several shots, and you could see the times where the lens aperture remained open after the shot was taken. It was then the shots taken after that situation that led to black frames.

Live view meters on what you are seeing I expect, so you don't have this issue? Assumptions there.
Last Edited by richandfleur on 11/05/2016 - 22:01

Nickbat

Link Posted 11/05/2016 - 22:14
richandfleur wrote:
I took a video of the front of the lens as I took several shots, and you could see the times where the lens aperture remained open after the shot was taken. It was then the shots taken after that situation that led to black frames.

Your logic is faultless. A lens aperture that remained open would certainly cause that. However (and I need to double-check this), I can take an LV shot, followed by an underexposed viewfinder shot (so far so good!), but if I then revert to the LV, I get a normal shot. How can that be if the aperture has remained open?

A bit baffled by all this, I must say!
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