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Old Jun 16, 2007, 11:31 PM   #1
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Please explain how to take a picture using the Pentax shake reduction.

When Iview a scene using the view finder or LCD screen on my"camcorder" that has optical image stabilization (OIS) built into the lens, I can see the shakey imageget steady when I turn the OIS on.

How do you see the picture get steady using the Pentax moving CCD method of shake reduction when you take a picture since the shake reduction is not in the lens?

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Old Jun 17, 2007, 12:19 AM   #2
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As there is no real time output from a SLR you don't.

Its also NOT a cure all.... it is an AID (and so is lens IS Canon and Nikon use) Though there you do see it, but there it can be deceptive, by not making you be as steady as you could maybe be because it looks OK... either system looks its best when it it doing as little as possible. Neither corrects extreme rapid movement well... like shutter jabbing instead of just squeezing..

And seeing it through the VF is only relevant down to the eye's 1/25th of a sec or so... below that its completely meaningless how it looks and where you need to be absolutely steady as possible and seeing the movement likely helps to physically minimize it, vs being decieved by seeing the at least 1/25th sec of the eye OK looking correction.

Just be as steady as you can be and have it turned on.

You want to see the effect after the fact, try the same slow shutter/long zoom shot without it.
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Old Jun 17, 2007, 12:23 AM   #3
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Hi skylark,

"How do you see the picture get steady using the Pentax moving CCD method of shake reduction when you take a picture since the shake reduction is not in the lens?"

You don't. You have to have faith that the SR is working, and see it in your results. Some consider this a disadvantage to sensor-based Image Stabilization (we call it Shake Reduction in these parts :-)), but we tend to like the fact that it works with all our lenses (even the 40+year old ones that many still use and love), instread of just the expensive ones that the mfgs have decided to include the feature in. You get used to it, and your bank account will thank you.

Scott
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Old Jun 17, 2007, 9:32 AM   #4
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Go to Shutter Priority and Start taking pictures at a certain speed (say 1/100)... take all handheld... one with SR on and one with SR off... drop the shutter speed and do the same thing at 1/80, 1/60, 1/50, 1/40, 1/30,etc, etc... and look at the difference of the pics with SR on and with SR off... that's about the only way you can "see" that it's working.
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Old Jun 17, 2007, 10:18 AM   #5
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Hi skylark, The reason why you see the results of image stablization with the camcorder and not with the SLR is based on system design for each camera type. In the camcorder design the ccd array or the sensor is taking the image real time and you the opertor are viewing a small TV screen showing the actual output of the sensor. If the sensor is image stablized, they you see the result.

In an SLR, there is a mirror in front of the ccd array or the sensor. You, the user look through the viewfinder that takes the view from that mirror that is viewing the scene through the lens. When you push the shutter button, the mirror flips up and the viewfinder goes blank for the instant that the image is being taken. The ccd array or the sensor is the item being stablized, so through the viewfinder you do not see the results. Thus with body based stablization you see no results in the viewer, but with lens based stablization you see the results since your looking through the lens.

Here is a great link showng shake reduction or image stablization...
http://www.dpnotes.com/testing-the-p...ction-feature/

You can essentially do your own test. Mount your longest lens (200mm??), crank it to the maximum focal length, and focus on a ceral box accross the room, looking at the text. Take 2 images, on with SR on and one with SR off. You will probably see some jitter in the text (or more jitter) with the image where the SR was off. This expirement has nothing to do with the lens, it is just easier to demonstrate SR with a longer lens. Same as holding a pencil out level versus an 8 foot 2x4. The far end of the 2x4 is going to have more bounce to it since the length will amplify what ever movement you make.

As Hayward pointed out, SR is an aid not an absolute correction. There are limits to the amount of "shake" that is removed.

Hope that helps....
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Old Jun 17, 2007, 11:56 AM   #6
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No one has mentioned (unless I missed it) the little green hand that shows up in the VF when SR is ready. I find I get better results if I leave it another couple of seconds before pressing the shutter, but that might just be because I'm shaking less.
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Old Jun 17, 2007, 1:00 PM   #7
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Hayward, inneyeseakay, interested_observer and SteveB,

Thanks for your informative replies. I believe I understand what to expect and how to take pictures using the Pentax method of SR now.

Much appreciated,

Skylark
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