Grains, pixels, and personal incompetence
Let me preface this post with a broad disclaimer: User error is the single most likely source of these problems. That being said, I've run across a few unwanted visual effects in some of the test footage I've shot.
I was using the 5296 preset found in the sticky thread above, and the standard gain settings (though I didn't mess with the gain, so it should be at the lowest of the standard settings). Also, I was shooting in 24f. My fstop, zoom, and shutter speed changed from time to time, as I was experimenting with different settings. When shooting inside, even during the day with bright sunlight, I seem to be getting a grainy image. I've searched on the forums and I've seen people suggest changing the gain settings to 0 or even -3db. Can anyone comment on whether that actually reduces gain? If it does, what do you give up and how do you compensate for it? When shooting outside, I notice some pixelation, particularly on the borders of strongly contrasting colors, like a black shirt on a white person. Is this normal? If not, what can I do to correct it? Finally, my footage looks much worse on an HD tv than a SD one. I assume that's because the HD TV is able to more accurately display my incompetence than an SD one. What settings concerns do you have to keep in mind specifically for HD? Thanks! |
You don't happen to have the AGC switch on the side of the camera set to ON do you?
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The grain effect is due in large part to slight differences in pixel dark current and sensitivity. It is most apparent in shadows areas of the image. Longer exposures can make dark current variations more apparent. Reducing gain has the effect of reducing the visibility of the differences in pixels. However, if reducing gain is accompanied by a corresponding slower shutter speed, the benefit may be reduced.
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I do not have AGC on. Should I?
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Note that AGC is automatically ON in Night and Easy Recording modes, OFF with gain set to 0 dB in Spotlight mode, and can be on or manually adjusted in other recording modes.. |
no should not put agv on :-)
I experienced the same problem as you. My problem was that my LCD of the A1 was not properly calibrated out of the box. I hooked it up to a tv screen and used that to calibrate it. Since the LCD was displaying everything to bright I usually made my lense opening smaller and put the shutter to fast. Once calibrated you should be able to reduce the grain by setting the lensopening and shutter speed to better values |
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If you were shooting at anything other than -3 or zero db, you're going to get grain. This is true with any camera. Shutter speed should be 1/48 for 24 fps, unless you're after an effect.
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Thanks for the settings advice. I've shot some test footage and it looks much cleaner than when I started.
Does anyone have any input for the pixelation problem I noticed on external/outside shots? |
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