K10 odd movement

As I said last night, I sent a quick e-mail off to Pentax UK about the slide-thunk issue.

My e-mail read:

I recently purchased a Pentax K10D. My question is;
When I rock the camera from the vertical, through 180 degrees, to the vertical, I can hear and feel a thunk. Can you explain what this?

And the reply, received today!

Thank you for your e-mail.

I am sorry to hear that you are having problems with your Pentax equipment. If you can send it in to Pentax House we shall get it checked for you.

Confused?

I am.

Clearly, unless they are so rushed off their feet that they have to resort to such fob-off techniques*, the Pentax support department is run by morons.

________
* to get rid of the undoubted 75% or more that don't realise you have to actually charge the battery before it will work

They don't help much do they. As an engineer I'm often flabbergasted by the BS that's relayed to me by technical people who don't know what they are talking about but should.

The fact is that if the sensor is making the "thunk sound" as it's rotated (sensor falling due to gravity) whilst an exposure is being made (or the camera is in cleaning mode) then it is faulty. It's best to check with the body capped so that any lens problems don't add noise.

Shooting a slow speed hand held image of a laser pointer output (strapped to the camera parallel with the lens axis) with SR on and off should prove if the SR system is actually functioning as intended.

It's pretty often commented on in other forums:

http://forums.dpreview.com/forums/read.asp?forum=1036&message=26054845
http://forums.dpreview.com/forums/read.asp?forum=1036&message=22422034
http://forums.dpreview.com/forums/read.asp?forum=1036&message=24257733
http://forums.dpreview.com/forums/read.asp?forum=1036&message=25436607
http://forums.dpreview.com/forums/read.asp?forum=1036&message=23190653
http://forums.dpreview.com/forums/read.asp?forum=1036&message=23972505

You say this is 'fact', but do you have an authority to cite for it?

I've now tested two K10Ds, bought at different times and places, both apparently functioning normally, and they both exhibit the thunk during long exposures, but only if SR is on.

I don't need authority just common sense. That noise is not due to gravity, it is the SR system polling due to the excessive movement of the body during the exposure. Just take the lens off, set a long exposure, and watch what the sensor does when you move the body. Rotating the camera through 90+ degrees during an exposure is not what the SR system was designed to counter, it will not make such a sound if the camera is handled normally.

Right, I'm pretty sure I know what's going on now, at least for my K10D.

I've taken the lens off and actually watched what's happening during long exposures, with SR on and off.

First with SR on:

The mirror pops up, and for small camera movements, you can see the sensor moving around as it tries to correct. It looks strange

Then if I increase the amplitude of the movements, there comes a point, where it appears that the SR 'gives up', and the sensor visibly flops to the extent of its movement, under gravity.

From then on, SR is ineffective, and the sensor moves about only due to gravity. Rotating the camera makes the thunk happen... and it is absolutely, definitely, beyond any doubt, the sensor moving that causes the noise. You can see it flop, and it thunks slightly as it hits the extent of its travel.

Once the exposure is complete, the SR sorts itself out on its own - the next exposure then has SR effective again. There is no need to switch off and on.

And with SR off:

The sensor does not move during the exposure, at all. Rotating the camera does not result in the sensor moving at all under gravity. So no thunk.

Notes

Whether the camera is operating as it's supposed to, I cannot say for certain, since I tend to avoid assuming that what I imagine to be common sense is necessarily fact.

However, I am reasonably confident that SR is functioning, at least for small movements of the camera.

A couple more observations:

It did not take a great deal of movement for the SR to 'give up' as I indicated above. Looking through the viewfinder, the little hand icon at the bottom on the left remained illuminated for the whole time, even after movements much larger than made the SR give up.

However, it does not seem that such large movements before the shutter opens cause failure of the SR system. I could half press the shutter, hold it half pressed, move the camera around through large movements, then complete the press with the camera making only small movements - with the camera then reasonably still, SR was clearly functioning. Which is nice.

Finally, I cannot be certain that the 'lens off' case is the same as the 'lens on' case. However, the presence or absence of 'thunkability' is the same in both cases.

I hope this is of interest. I'll now get on to removing the dust that my camera is doubtless now full of...

Interesting experiment thanks for that

One more thing.. I observed what happened if I changed the focal length the camera was set to.

As expected, the longer the focal length set, the more the sensor moved about.

Set to 800mm, I couldn't hold it still enough - it wasn't long before large enough sensor movements took place for it to give up.

I knew that it resets after a polling episode but I didn't realize that it went limp from that point on during the remainder of the exposure. Thanks for pointing that out I've never been so rough with my camera to find out.

It behaves exactly the same way lens on or lens off because shooting without a lens on is like shooting with any non-auto aperture lens.

Someone should let Pentax techs know how their cameras work ;-(

Just as an exercise, to test the competence of the Pentax technical team, I sent off another e-mail to them last night.

It read:

I think my camera might be faulty. A friend suggested it might be the giggling pin interferring with the flux capacitor. I mounted the camera on some sky hooks, but someone had borrowed my left-handed screwdriver and I was unable to investigate it further. What do you suggest?

And the reply:

Thank you for your e-mail.

I am sorry to hear that you are having problems with your Pentax equipment. If you can send it in to Pentax House we shall get it checked for you.

So from this I have surmised that they are not morons or busy, they just have a big machine that reads all the incoming e-mails and post back a standard reply.
I reckon that as long as you include the words, "camera" and "fault" in the first sentence, you could ask them if the moon was made of cheese and receive the same reply!

Of course. I said Actual tech guys are often very good, and I expect they're as frustrated with their lot as we are with ours.

It's the people running it that are morons. They imagine that an automated system that generally annoys the hell out of anyone with an actual problem is A Good Thing.

As I say, either they're morons, or we simply have no idea at all of the sheer number of greater morons deluging their people with stupid questions all the time, that they have no alternative but to implement a ludicrously crude filtering mechanism.

Here's the logic I imagine:

1. They waste our time with stupid questions.
2. If they can't be arsed to send us the camera, they probably don't have a serious enough problem.
3. If they do send us the camera, we can look at it without having to talk to idiots. Then we can fix it if there's a problem, and send it back in return for money. Result!

This would be understandable if it didn't fall down with the problem people seem to recount with depressing frequency, namely that cameras sent in, come back either unfixed or worse.

So enough of the actual tech guys are either too busy, and are being crapped on by their management, or aren't all that good either.

It's a wonder any cameras work at all.

Definitely makes you wonder, a recent Pentax service experience of mine (won't even go into the protracted K10D saga I've just been through):

http://picasaweb.google.com/distudio/W20AFZoomTest

;-(