K10D making strange buzz - do I need to worry?

Dear All

while taking some macros using cable release on a tripod with my Sigma 50mm earlier this evening, while composing a shot I noticed my K10D make a sudden loud scraping / buzzing noise almost like that of a drill bit scraping metal. I hadn't banged the end of lens into the subject or anything like that to prevent AF from extending the lens barrel, so rather worried I shut the camera off and packed away.

Took some test photos under daylight floods with a couple of different lenses, and they all focussed OK, so put the macro lens back on and shot some more non macro tests with it. Again, all OK and in focus. In both cases, AF seemed a little slow on one or two shots, but that might just be me being overconcerned.

However, if I listen, after the shutter fires, there is sort of quiet electrical hum (almost a buzz) briefly, and if I take a bulb exposure that hum is also present for the duration that the shutter is open. I'm sure it never did that before!

I then finally took some more photos, and part way through the camera decided to act as if I was set on MF despite being set on AF (and MF was showing in the finder). It wouldn't return to normal operation until I powered off the camera, took the lens off and remounted it, then all was fine again apart from the strange humming noise.

Do I need to worry?
Should I send my K10D off to Pentax?
Anyone else had this problem?
Anyone else's K10D make a strange humming/crackling noise like mine seems to have started doing?

Help!

Cheers

Dave

When things make noises they didn't before and strange things happen for no apparent reason I would pay attention to it, just in case some further damage is being done.

Try turning off SR and check for noises again
The SR makes a very, very slight noise (a result of the magnetic mount and the K10D correcting for movement) - it's more of a quiet purr though.
Matt

What was the macro lens and setup? I've seen problems when using TC's in low light, especially on older lenses, where the camera has difficulty detecting the length of the lens which sends the SR into overdrive if enabled.

Are you sure the lens was on properly? If not engaged correctly, the auto-focus mechanism can make a whirring noise at is fruitlessly attempts to adjust the lens.

Very good point! Hence my concern.

There hasn't been any more obviously mechanical noise and AF seems to be OK at the moment with both the 18-55 kit lens, the 50mm sigma and my 75-300 sigma, there's just this strange brief quiet crackly/scratchy hum which I've certainly not noticed before.

I've turned off SR and the crackly hum is still present briefly after the shutter fires / during bulb.

It does sounds a bit like a quiet purr as if heard through a very poor quality speaker - I think you may be right and it's something to do with the SR mechanism, but I've certainly not noticed it before.

Although considering that the noise is present even with SR Off, not sure why it would be that.

Sigma EX 1:2.8 50mm DG Macro, about 1 1/2 months old. Camera on tripod with cable release to fire shutter, SR turned off.

Lens was definately engaged correctly. Looking at both the lens mount and the back of the lens no visible damage or marking to either the contacts or the AF screw.

What do people advise, should I just keep an eye on things for a month or so and if the noise gets worse / louder (or if any other strange things happen) then send the camera to Pentax while still under warranty, or should I send it off to Pentax now? (It's just under 4 months old at present - 4 months on 21-11-2007)

Cheers

Mine makes a very quiet, as you say, scratchy hum, when the shutter's open, with or without SR.

"loud scraping / buzzing noises" don't sound good, though.

Is it possible that the AF screw slot is worn, and didn't engage properly? Just clutching at straws.

I just rang Pentax to ask their opinion on best course of action, and the techie I spoke to said he's not heard of that problem before and asked me to email them a description - I'll condense my responses here into a single email and I'll let you guys know how I get on.

Dave

Ahhh, yours does the same scratchy hum when the shutter is open. That's definately the noise I'm hearing - and while quiet it's definately there.

Maybe I just hadn't noticed the quiet scratchy hum before and I'm only noticing it now because I'm oversensetive to any noises from the camera since the terrifying grating noise!

AF screw slot doesn't appear to be worn.

Oh hang on a minute.

Does the green button try and stop down the lens and run the autofocus motor?

Thinking back about it, I had just put my Lensbaby 3G on when the scary noise happened and I'd pressed "green" to grab the ideal settings (was in fully manual mode). So it's possible the AF/MF switch was in AF mode. I wonder if the scary noise was the camera trying to stop down and AF the lensbaby and was the noise of the AF screw trying to spin on the bottom of the lensbaby's mount?

I didn't take the shot I was composing, and instead powered off and put the 50mm sigma straight back on - and it was on the camera as I was writing my original post...

Thoughts?

Yes and no. The green button just does exposure. Is it possible the actuator lever for the aperture would make the noise somehow with the Lensbaby?

Dan

Not sure how it could because there is no aperture control on the lensbaby that would mate with the aperture actuator in the body.

Of course, it could have been the actuator trying to move a non-existent lever combined with depressing the shutter half way causing the AF motor to try and spin up against the lensbaby base if I hadn't switched the body to MF mode that made the awful noise.

Went out during lunch and took a card's worth of RAWs of the wildlife on and around the lake in the grounds and I couldn't hear the quiet scratchy hum at all.

I think therefore that I've never noticed that hum before and I was only noticing it last night because I was indoors in a silent house (the Mrs had popped out to Sainsburys for milk when the initial noise happened) and I was super sensetive to odd noises from my camera following the nasty initial noise.

I'll check the photos tonight (all taken on the 75-300 Sigma) to make sure they're sharp to rule out any lingering AF problem and then run it all by Pentax and see what they reckon, just to be on the safe side.

Cheers.

Dave

I reckon it's the "non-Pentax-lens-detected-possibly-reads-internet-forums-containing-occasional-criticism-of-Pentax-we'll-just-scare-him-this-time" feature.

Could be I've heard some funny noises when using a tele-converter, principally it sounded like the SR operating after the shutter had closed.

Well the photos I took that lunch were sharp, and test photos using a sheet of text, good even light and camera on tripod have all come out sharp.

There have been no further weird mechanical noises from the camera, and the scratchy hum is only noticeable when using the camera in silent locations (so I reckon it was there all along and I just never noticed it before).

I'm going to keep an eye on things, but I think I'll chalk this up to a combination of possible user error and ChrisA's "non-Pentax-lens-detected-possibly-reads-internet-forums-containing-occasional-criticism-of-Pentax-we'll-just-scare-him-this-time" feature.

Cheers guys

Dave

2 points come to mind

1: My K10D also makes a very slight hum with the shutter open, SR or no SR. I think it is because even with SR off, the sensor mounting still has to activate in order to hold the sensor on station. It has always done this.

2: Even if there is no actuator on the lens, hitting the green button will cause the aperture actuator on the camera to descend. This makes a pronounced scratchy, squeeky noise. I would have thought you'd have heard it before, but you may always have been concentrating too hard on the shot to notice. It's amazing what one can miss when concentrating.

fingers crossed that's all it is!