K5 Sensor cleaning: bug?

blende8 · 11-20-2010, 12:09 PM

My K5 makes this cleaning sound when I turn it on and also when it awakes from sleep. So far so good.
But I cannot turn it off. When I remove the check for the start action it is still doing it.
Also, when I want to do sensor cleaning manually through the menu, it does not work at all.
I have firmware 1.01.

Anyone?

Last edited by blende8; 11-20-2010 at 12:38 PM.

Col · 11-20-2010, 12:31 PM

Yes, just get the wizz sound on power up no matter whether the option is ticked and nothing happens manually selecting dust removal (nice graphic hadn't seen that one before). v1.01

blende8 · 11-20-2010, 12:37 PM

I was wrong.
What you hear is not the sensor cleaning.
It is the aperture lever getting into place. Not sure why this is so.
You can see this, when you look into the camera without lens and turn it on.

I have been told that the sensor cleaning is absolutely silent.

Col · 11-20-2010, 12:47 PM

Learn a new Pentax fact each day... I always had anti dust set on start up (unless I was doing a long shoot and didn't want the dust bunnies to move) So I had assumed the start up whirr was the anti dust.

Still It would be nice to have a few menu options which you could play with which had no effect, to keep me entertained on rainy afternoons.

kittykat46 · 11-20-2010, 07:35 PM

Originally posted by blende8

I was wrong.
What you hear is not the sensor cleaning.
It is the aperture lever getting into place. Not sure why this is so.
You can see this, when you look into the camera without lens and turn it on.

I have been told that the sensor cleaning is absolutely silent.

That's the aperture lever setup since the K-7.
Its normal.

eigelb · 11-21-2010, 03:43 AM

Is this scratching noise caused by the aperture lever really normal i would be really pacified when it is so ?

blende8 · 11-21-2010, 07:00 AM

I have been told that it is normal and already so in the K7.
What I still don't know is what it is doing.

kittykat46 · 11-21-2010, 09:29 AM

Originally posted by eigelb

Is this scratching noise caused by the aperture lever really normal i would be really pacified when it is so ?

Originally posted by blende8

I have been told that it is normal and already so in the K7.
What I still don't know is what it is doing.

I don't really know enough about the electronically-controlled Aperture lever on the K-5/ K-7 to say much about it.

I can only add that my K-7 has been turned on/off many hundreds of times, and the brief "scratching" sound at startup isn't a camera malfunction.

falconeye · 11-21-2010, 09:55 AM

It seems the scratching noise from the aperture motor remained the same between K-7 and K-5.

However, the ultrasonic "Dust Removal" wasn't entirely inaudible for the K-7. In the K-5, at least for my ears it is with the lens mounted.

Nevertheless, with open bajonett when you power up the K-5, you first hear the scratching aperture motor followed a fraction of a second later, by a faint high pitch noise of the ultrasonic dust removal. With your ear near the mount opening.

inferno10 · 11-21-2010, 10:13 AM

Originally posted by falconeye

However, the ultrasonic "Dust Removal" wasn't entirely inaudible for the K-7. In the K-5, at least for my ears it is with the lens mounted.

For me, it was the opposite. You could hear my K-7's DR mechanism, which sounded like a hand screeching across a clean pane of glass or a nail going across a chalkboard; this was still barely audible, but was discernible from the first sound. In the case with my rental K-5, the DR mechanism was even less audible.

- Jason

falconeye · 11-21-2010, 10:26 AM

Originally posted by blende8

What I still don't know is what it is doing.

AFAIK, it's a motor.

Normally, if you mount a lens, the aperture lever is turned by the force of mounting the lens. So, the lens is aperture open as soon as it is mounted and closed when off.

If you make a shot, the lever is released and the aperture spring closes the lens until the predetermined stop. After the shot, the lever is brought back into mounted position by the same mechanics which rewinds the shutter curtains and lowers the mirror.

This spring/block/rewind mechanics can only move the block position (change the f-stop) if the lever is disengaged, i.e., if the block has no pressure from the lever and aperture spring. I.e., the aperture must be fully open to change the f-stop (in A position).

With the K-7/5, the body-side lever isn't a spring/block mechanics anymore. It's a motor which is powerful enough to push the lever against the aperture spring force and precise enough to push it exactly into the desired position. A side effect is that a manual aperture ring (non A position) seems to have no effect anymore.

This change became necessary to allow a change of f-stop during LV and especially, during video recording.

Actually, I'm not sure how many brands allow a fully automatic aperture control during video with legacy lenses.

The noise at the beginning doesn't close down the lens. So, it's not from moving the aperture lever by any significant distance. The noise from moving the aperture lever for stopping down is similiar but not as loud. But if you look very careful upon start-up with no lens, you'll see that the scratch noise is from the lever vibrating by ~1/4 mm for as long as the noise lasts. So, it may try to probe for some start position or to calibrate some motor parameter.

---------- Post added 11-21-10 at 06:28 PM ----------

Originally posted by inferno10

For me, it was the opposite. You could hear my K-7's DR mechanism, which sounded like a hand screeching across a clean pane of glass or a nail going across a chalkboard; this was still barely audible, but was discernible from the first sound. In the case with my rental K-5, the DR mechanism was even less audible.

Jason, what I said. Double negation and English language

blende8 · 11-21-2010, 12:48 PM

Thanks Falk for the explanation!
It's interesting, when you look into the DA16-50 at 16mm, when you turn the camera on, you can see that the aperture is closing for a moment.

11-20-2010, 12:09 PM	#1
blende8 Veteran Member Join Date: Feb 2007 Location: Bremen, Germany Photos: Albums Posts: 1,521	K5 Sensor cleaning My K5 makes this cleaning sound when I turn it on and also when it awakes from sleep. So far so good. But I cannot turn it off. When I remove the check for the start action it is still doing it. Also, when I want to do sensor cleaning manually through the menu, it does not work at all. I have firmware 1.01. Anyone? Last edited by blende8; 11-20-2010 at 12:38 PM.

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11-20-2010, 12:31 PM	#2
Col Veteran Member Join Date: Apr 2007 Location: Stansted Essex Photos: Gallery Posts: 614	Yes, just get the wizz sound on power up no matter whether the option is ticked and nothing happens manually selecting dust removal (nice graphic hadn't seen that one before). v1.01

11-20-2010, 12:37 PM	#3
blende8 Veteran Member Join Date: Feb 2007 Location: Bremen, Germany Photos: Albums Posts: 1,521 Original Poster	I was wrong. What you hear is not the sensor cleaning. It is the aperture lever getting into place. Not sure why this is so. You can see this, when you look into the camera without lens and turn it on. I have been told that the sensor cleaning is absolutely silent.

11-20-2010, 12:47 PM	#4
Col Veteran Member Join Date: Apr 2007 Location: Stansted Essex Photos: Gallery Posts: 614	Learn a new Pentax fact each day... I always had anti dust set on start up (unless I was doing a long shoot and didn't want the dust bunnies to move) So I had assumed the start up whirr was the anti dust. Still It would be nice to have a few menu options which you could play with which had no effect, to keep me entertained on rainy afternoons.

11-20-2010, 07:35 PM	#5
kittykat46 Veteran Member Join Date: Dec 2007 Posts: 923	Originally posted by blende8 I was wrong. What you hear is not the sensor cleaning. It is the aperture lever getting into place. Not sure why this is so. You can see this, when you look into the camera without lens and turn it on. I have been told that the sensor cleaning is absolutely silent. That's the aperture lever setup since the K-7. Its normal.

11-21-2010, 03:43 AM	#6
eigelb Inactive Account Join Date: Mar 2009 Location: Italy Posts: 174	Is this scratching noise caused by the aperture lever really normal i would be really pacified when it is so ?

11-21-2010, 07:00 AM	#7
blende8 Veteran Member Join Date: Feb 2007 Location: Bremen, Germany Photos: Albums Posts: 1,521 Original Poster	I have been told that it is normal and already so in the K7. What I still don't know is what it is doing.

11-21-2010, 09:29 AM	#8
kittykat46 Veteran Member Join Date: Dec 2007 Posts: 923	Originally posted by eigelb Is this scratching noise caused by the aperture lever really normal i would be really pacified when it is so ? Originally posted by blende8 I have been told that it is normal and already so in the K7. What I still don't know is what it is doing. I don't really know enough about the electronically-controlled Aperture lever on the K-5/ K-7 to say much about it. I can only add that my K-7 has been turned on/off many hundreds of times, and the brief "scratching" sound at startup isn't a camera malfunction.

11-21-2010, 09:55 AM	#9
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871	It seems the scratching noise from the aperture motor remained the same between K-7 and K-5. However, the ultrasonic "Dust Removal" wasn't entirely inaudible for the K-7. In the K-5, at least for my ears it is with the lens mounted. Nevertheless, with open bajonett when you power up the K-5, you first hear the scratching aperture motor followed a fraction of a second later, by a faint high pitch noise of the ultrasonic dust removal. With your ear near the mount opening.

11-21-2010, 10:13 AM	#10
inferno10 Veteran Member Join Date: Feb 2007 Location: San Francisco, California Posts: 342	Originally posted by falconeye However, the ultrasonic "Dust Removal" wasn't entirely inaudible for the K-7. In the K-5, at least for my ears it is with the lens mounted. For me, it was the opposite. You could hear my K-7's DR mechanism, which sounded like a hand screeching across a clean pane of glass or a nail going across a chalkboard; this was still barely audible, but was discernible from the first sound. In the case with my rental K-5, the DR mechanism was even less audible. - Jason

11-21-2010, 10:26 AM	#11
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871	Originally posted by blende8 What I still don't know is what it is doing. AFAIK, it's a motor. Normally, if you mount a lens, the aperture lever is turned by the force of mounting the lens. So, the lens is aperture open as soon as it is mounted and closed when off. If you make a shot, the lever is released and the aperture spring closes the lens until the predetermined stop. After the shot, the lever is brought back into mounted position by the same mechanics which rewinds the shutter curtains and lowers the mirror. This spring/block/rewind mechanics can only move the block position (change the f-stop) if the lever is disengaged, i.e., if the block has no pressure from the lever and aperture spring. I.e., the aperture must be fully open to change the f-stop (in A position). With the K-7/5, the body-side lever isn't a spring/block mechanics anymore. It's a motor which is powerful enough to push the lever against the aperture spring force and precise enough to push it exactly into the desired position. A side effect is that a manual aperture ring (non A position) seems to have no effect anymore. This change became necessary to allow a change of f-stop during LV and especially, during video recording. Actually, I'm not sure how many brands allow a fully automatic aperture control during video with legacy lenses. The noise at the beginning doesn't close down the lens. So, it's not from moving the aperture lever by any significant distance. The noise from moving the aperture lever for stopping down is similiar but not as loud. But if you look very careful upon start-up with no lens, you'll see that the scratch noise is from the lever vibrating by ~1/4 mm for as long as the noise lasts. So, it may try to probe for some start position or to calibrate some motor parameter. ---------- Post added 11-21-10 at 06:28 PM ---------- Originally posted by inferno10 For me, it was the opposite. You could hear my K-7's DR mechanism, which sounded like a hand screeching across a clean pane of glass or a nail going across a chalkboard; this was still barely audible, but was discernible from the first sound. In the case with my rental K-5, the DR mechanism was even less audible. Jason, what I said. Double negation and English language

11-21-2010, 12:48 PM	#12
blende8 Veteran Member Join Date: Feb 2007 Location: Bremen, Germany Photos: Albums Posts: 1,521 Original Poster	Thanks Falk for the explanation! It's interesting, when you look into the DA16-50 at 16mm, when you turn the camera on, you can see that the aperture is closing for a moment.