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May 31st, 2006, 02:32 PM | #1 |
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Super Steady Shot - Yes or No?
With HDV cams any shaking really shows up in the output.
I've searched is forum as well as others, but I still haven't seen anything conclusive on whether turning on the Super Steady Shot actually affects the output resolution and if so, how much... Since I don't have a nice large screen HDTV I can't reliably test this myself... Any of you out there seeing any visible resolution differences? |
May 31st, 2006, 03:04 PM | #2 | |
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Steady shot on HC1
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I read somewhere that the Sony HC1 has some form of solid state gyro that senses movement and applies the correction btw. |
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May 31st, 2006, 03:26 PM | #3 |
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I haven't read about a gyro, but I've read about how it takes the spare pixels and uses them.
But I'm kind of funny in that I trust people's eyes better than theory, as I've found too often it doesn't match with experience. Usually due to factors that were left out. That said, have you seen any differences? |
May 31st, 2006, 03:45 PM | #4 |
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Always use steadyshot when handheld. If you want to test the extent of the stabilization, tape a drinking straw or something to the top of the cam so that it is in the frame. Walk around. The apparent motion of the object relative to what you are filming is the stabilization.
The electronic stabilization works by cropping out part of the image received from the sensor. So you give up perhaps 10% resolution vertically. You don't give up anything horizontally, since it will be downsized to 1440 horizontal anyway. You can change the amount of stabilization (ie pixels used for stabilization), it is the Conv Lens option in the camera settings menu. Wide Angle is the lowest setting, Tele is the highest. |
May 31st, 2006, 04:48 PM | #5 |
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In theory, supposedly at least most of the pixels used in the Super SteadyShot aren't usually used in the actual capture anyway.
Here's what Sony says: " Super SteadyShotŪ Picture Stabilization minimizes camcorder "jitter" and "shake" without any change to the quality of the image "Super SteadyShotŪ Picture Stabilization uses horizontal and vertical motion sensors located inside the lens assembly area. These sensors detect high frequency camcorder motion, like you might experience in a moving car, and an oversized CCD chip compensates for the movement. "The Super SteadyShotŪ system utilizes a Hyper Precision CCD chip with up to 3,300K pixels. Only 330K pixels are required to deliver an excellent picture, though Sony uses up to 690K. The extra pixels on the chip compensate for horizontal and vertical motion, minimizing camcorder shake without degrading the picture quality. Different than most other digital image stabilization systems, Super SteadyShotŪ produces clear images even while zooming, shooting moving objects, or shooting in low light." But I'm wondering if anyone is actually seeing differences. |
May 31st, 2006, 05:14 PM | #6 |
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Okay. Further searching the forum using steadyshot as one word has yielded this from Chris Hurd himself:
"There is no loss of image quality with today's improved EIS. Please do your research. Understand that Sony for example uses the term "Super SteadyShot" to refer to lossless IS and that sometimes this is optical, sometimes it is electronic." http://www.dvinfo.net/conf/showthrea...ght=steadyshot He seemed to be pretty certain on this. |
May 31st, 2006, 06:14 PM | #7 | |
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Chris is comparing EIS with OIS, and says that if you have surplus pixels, then EIS need not involve a loss. The sensor on the HC1 and the A1 does have such a surplus, mostly in the horizontal direction. Steadyshot does lead to a slight loss of vertical resolution, but I find it acceptable. You can check this by shooting with and without the full-scan mode enabled. Another experiment you can do is to shoot a still scene with steadyshot enabled, and with the various conversion lens options. The "wide" option has the smallest amount of correction, the "tele" option has the largest - and hence the lowest resolution. If you peer at a still frame, you can see a slight difference. In motion, there is practically no difference. The improvement from the Steadyshot outweighs, by far, any decrease in resolution. Check it for yourself! |
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May 31st, 2006, 06:25 PM | #8 |
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Thank you Gian!
I have checked it myself, but only on my computer screen and my non-HD TV. It seemed fine, but I was still concerned how it would look if played on an HDTV or ever was transferred to film. I'm starting to think there would little perceivable difference and that the benefit of steady handhelds would far outweigh any slight loss. Perhaps I was just being paranoid. Heh. |
May 31st, 2006, 07:23 PM | #9 |
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Variable Stabilization Margins with EIS on HC3
I don't know if this also applies to the A1 and HC1, but the EIS system of the HC3 uses variable-width margins at the edge of its CMOS. They vary in width and in the number of pixels they use, according to the position of the zoom setting. They are widest at full zoom and narrower at a wide position.
At least in theory, when more pixels are used for EIS, the resolution and overall image quality should diminish. However, with the interpolation that is used with the HC3 to create "virtual" pixels, when not enough are available on the active portion of the CMOS, this doesn't seem to be a significant problem. The HC3 does not have a "Full-scan" option, like the A1, where the EIS can be turned off and the full CMOS becomes active for the image. Therefore, there would be no improvement in the image for the HC3, if the EIS could be turned off. The use of an EIS system has the added effect of increasing the image magnification. Since a smaller active CMOS sensing area is used with EIS, a smaller part of the optical image from the lens is used to fill the video frame. Although the HC3 has a 10X zoom, the magnification effect is 11.25X, when the lens is at full zoom. You get 22.5X magnification at full zoom with an HC3, when a 2X telexender is used. It's necessary to understand that the specifications for the zoom range of a lens and its magnification power are not the same thing. In some cases the "X" powers of zoom and magnification are the same, but this is only coincidental.
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May 31st, 2006, 07:54 PM | #10 | |
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June 1st, 2006, 02:14 AM | #11 |
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yes yes
HC1 or the A1 do not use the 1920 res eventhough the camera has horizontal resolution to spare. They start cropping at 1440.
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June 1st, 2006, 07:00 AM | #12 | |
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HC1 too
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June 1st, 2006, 08:02 AM | #13 |
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Thanks! I wanted to be very sure of myself since I was hoping to bring some of the output to film one day.
And of course, all the books say in big letters DON'T USE AUTOMATIC STABILIZERS. But when most of these books were written the stabilizers were pretty lossy and I knew there had been huge gains in that area. Thanks again. |
June 1st, 2006, 10:56 PM | #14 | |
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