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02-10-2010, 09:38 AM   #16
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QuoteOriginally posted by slowdive101 Quote
Yes, it's a convenience, but it's decidedly inconvenient to have to remember to turn it on and off.
If your camera didn't have this feature, I know you would complain as well why there isn't an SR available!

02-10-2010, 09:50 AM   #17
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QuoteOriginally posted by GerryL Quote
If your camera didn't have this feature, I know you would complain as well why there isn't an SR available!
Probably...Although, I wouldn't have bought it without SR.
02-10-2010, 12:40 PM   #18
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Been thinking about this too but after reading about the sensor and SR design in the Kx Im leaning towards leaving it on. It seems that the SR has no engine or anything like that that would be active but instead the sensor is hung up between a bunch of magnets. Seems to be a different design then most others.

And if there is no active engine there shouldnt be any ghost shakes or similar, just as someone already tested here a few posts up.

If this is true it also means that the SR use no batteries or causes any delays so I cant really see any harm in leaving it on.
If you have a steady hand the SR will work much less but if you for some reason have a chill it will help you keep it a little bit more steady and maybe even save the shot
02-10-2010, 01:11 PM   #19
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If you search this forum (and/or dpreview), you'll find this topic discussed quite often. I am not convinced there has been a really definitive answer, though - just several fairly convincing but pretty much contradictory theories.

02-10-2010, 01:25 PM   #20
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QuoteOriginally posted by aliasant Quote
Been thinking about this too but after reading about the sensor and SR design in the Kx Im leaning towards leaving it on. It seems that the SR has no engine or anything like that that would be active but instead the sensor is hung up between a bunch of magnets. Seems to be a different design then most others.

And if there is no active engine there shouldnt be any ghost shakes or similar, just as someone already tested here a few posts up.

If this is true it also means that the SR use no batteries or causes any delays so I cant really see any harm in leaving it on.
If you have a steady hand the SR will work much less but if you for some reason have a chill it will help you keep it a little bit more steady and maybe even save the shot
Some of the magnets are electro-magnets meaning they must be energized with electric current. Whenever the electric current stops flowing, they stop being "magnetic". That also means the electric current must flow at precisely a certain "constant" amount in order to hold the sensor motionless.

http://www.pentaximaging.com/files/scms_docs/SHAKE_REDUCTION_FACT_SHEET.pdf
02-10-2010, 02:21 PM   #21
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QuoteOriginally posted by aliasant Quote
And if there is no active engine there shouldnt be any ghost shakes or similar, just as someone already tested here a few posts up.
The sensor position is controlled by electric motors of voice coil type, very similar to those found in hard drives which moves the read/write heads back and forth.
02-10-2010, 08:20 PM   #22
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QuoteOriginally posted by Gimbal Quote
The sensor position is controlled by electric motors of voice coil type, very similar to those found in hard drives which moves the read/write heads back and forth.
Not exactly electric motors according to the following paragraph from the above document from Pentax.

"Over 30 patents have been filed for this SR system, which uses a ball-bearing-mounted oscillator
unit with four electromagnets that hold the free-floating image sensor. Angular velocity sensors
detect camera movement and relay the amount of compensation necessary to the electromagnets
that move the sensor to compensate for any shake
."

The above is the original SR from Pentax. The sensor can be moved in three directions: vertically, horizontally and rotationally.

According to a recent US patent filing from Pentax, it has a newer SR which moves the sensor in only two directions: vertically and horizontally. It appears this SR system uses voice coil actuators to move the sensor. I think one advantage of this new SR system is sensor stability when the camera is not moving. The sensor can rest on the vertical and horizontal guide bars/actuators. This new SR system was first filed in Japan in July 2008. This patent specifically uses a DSLR as an example which uses this new SR system.

http://www.freepatentsonline.com/pdf_collections_server1/usapp/patent_pdf/20...0100020184.pdf

According to this K-x descriptions below, it appears the K-x may be using the newer SR system and the K-7 is using the older type. Thus it may make sense that some users are finding the K-x can take blur free photos with SR enabled and on a tripod.

"Like almost all shake reduction systems, the Kx's shake reduction can correct only for horizontal or vertical motion, but not for rotation -- a rare capability that is offered by the K-7."

http://www.imaging-resource.com/PRODS/KX/KXA.HTM

Last edited by ma318; 02-10-2010 at 09:52 PM.
02-10-2010, 11:00 PM   #23
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QuoteOriginally posted by sterretje Quote
Read page 68 of your user manual.
Wow, I missed that - I thought it's a new feature on the newer cameras - I was always turning it off when doing delay shutter on a tripod not knowing it's already off.

I must have not set the camera on delay shutter yet when I've got those vibrations.

02-11-2010, 01:43 AM   #24
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QuoteOriginally posted by ma318 Quote
Not exactly electric motors according to the following paragraph from the above document from Pentax.

"Over 30 patents have been filed for this SR system, which uses a ball-bearing-mounted oscillator
unit with four electromagnets that hold the free-floating image sensor. Angular velocity sensors
detect camera movement and relay the amount of compensation necessary to the electromagnets
that move the sensor to compensate for any shake
."

The above is the original SR from Pentax. The sensor can be moved in three directions: vertically, horizontally and rotationally.

According to a recent US patent filing from Pentax, it has a newer SR which moves the sensor in only two directions: vertically and horizontally. It appears this SR system uses voice coil actuators to move the sensor. I think one advantage of this new SR system is sensor stability when the camera is not moving. The sensor can rest on the vertical and horizontal guide bars/actuators. This new SR system was first filed in Japan in July 2008. This patent specifically uses a DSLR as an example which uses this new SR system.

http://www.freepatentsonline.com/pdf_collections_server1/usapp/patent_pdf/20...0100020184.pdf

According to this K-x descriptions below, it appears the K-x may be using the newer SR system and the K-7 is using the older type. Thus it may make sense that some users are finding the K-x can take blur free photos with SR enabled and on a tripod.

"Like almost all shake reduction systems, the Kx's shake reduction can correct only for horizontal or vertical motion, but not for rotation -- a rare capability that is offered by the K-7."

Pentax K-x Digital Camera - Hands-On Preview - The Imaging Resource!
Yes, electromagnets are an essential part of an electric motor. You also need permanent magnets (or even more electric magnets) to complete the motor. In this case, as in the hard drives head assembly, they use permanent magnets. This type of linear motor is called a voice coil.

By alternating the current through the magnets the sensor can be moved to whatever position the SR wants the sensor to be.

The new patent seems to be more of the same, merely another construction that perhaps is cheaper to build, or stronger but otherwise it is the same thing.
02-11-2010, 08:47 AM   #25
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QuoteOriginally posted by Gimbal Quote

The new patent seems to be more of the same, merely another construction that perhaps is cheaper to build, or stronger but otherwise it is the same thing.
No, the two designs are quite different. The older one uses a free floating sensor plate whose movements are controlled by electromagnets and permanent magnets.

With the new design, the sensor rests on a horizontal guide bar/actuator and a vertical guide bar/actuator. It is not exactly "free floating" as the older design. The newer design also uses voice coil actuators to move the sensors. While the older design uses electromagnet and permanent magnets.

Anyway the fact that they were allowed to file a new patent for the new SR system means it must be a different design - at least different enough to the patent office.
02-11-2010, 09:10 AM   #26
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I agree in that there are some mechanical differences, but the main function is still the same. Use voice coil motors to move the sensor.

Old design uses flat electromagnets on flat permanent magnets, new design use round electromagnets on round rod-shaped permanent magnets. Old design has the sensorplate resting on ball bearings, new design has the sensorplate guided by rods.

The old design looks more elegant to me and I don't really see what the benefit is with the new design, but there probably is something good with it. Hm, perhaps they only filed it to block competition?
02-11-2010, 09:20 AM   #27
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One advantage I think with the new design is the ability to support a heavier/larger sensor. Pentax would need something like this if they want to go FF. Apparently the Sony SR design that is used on their FF (A900) is similar to Pentax's new SR design. However Pentax managed to eliminate a couple of guide rails from the Sony SR design so that Pentax new SR design is more compact.

I agree that the older design is more elegant.

Last edited by ma318; 02-11-2010 at 10:02 AM.
02-11-2010, 09:54 AM   #28
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You need to turn it off if you´re using an older zoom lens that doesn´t give the camera focal length information. SR for 105mm at 35mm will not give you a satisfying result.
02-11-2010, 10:01 AM   #29
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QuoteOriginally posted by ma318 Quote
One advantage I think with the new design is the ability to support a heavier/larger sensor. Pentax would need something like this if they want to go FF. Apparently the Sony SR design that is used on their FF (A900) is similar to Pentax's new SR design. However Pentax managed to eliminate a couple of guide rails from the Sony SR design so that Pentax new SR design is more compact.
For their (upcoming?) MF maybe ?
02-11-2010, 10:12 AM   #30
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Could be. But some people believes that SR is not needed for MF - at least for now. Pentax does not need to use it for MF in order to compete with others because no current digital MF has build-in SR. The patent of the new SR design also stresses on its compactness because Pentax manages to eliminate a couple of guide rails like those used in the Sony SR design. Is compactness critical for MF? I guess it could be if Pentax intends to compete with the Leica S2 on compactness.
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