Technical question regarding sensor
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Changing the image size between small, medium and large changes the number of pixels being recorded by the camera. So, medium is more or less using every other pixel across the entire sensor.
A medium size image may appear sharper to the eye because the loss of pixels is also a loss of detail along the edges, effectively smoothing them a little.
What suffers going from large to medium is the print size. A large image size can be printed (or viewed) larger than a medium and there will be more detail in the large image size.
A medium size image may appear sharper to the eye because the loss of pixels is also a loss of detail along the edges, effectively smoothing them a little.
What suffers going from large to medium is the print size. A large image size can be printed (or viewed) larger than a medium and there will be more detail in the large image size.
My guess is it just does a simple resample to the smaller sizes (always from the full image capture).
Because Large is 100%, Medium is 75%, and Small is 50%. The 75% would be a sub-sampling problem, and sub-sampling can cause aliasing (moire) and loss of dynamic range. Why not resample?
Either way, smaller is a loss of resolution... but that is speaking of a 100% view. Unless printing murals, we always have to resample (or crop) a 24 megapixel image to use it. Normal monitor screens are at most about 2 megapixels, and an 8x10 print is about 7 megapixels. They cannot show 24 megapixels.
I'd add that Medium size is a choice if you want a smaller file or image, but always leave JPG Quality at Fine. There would seem no point of a lower quality image.
My puzzle is about video format, to 1920x1080. We are led to believe some of the advantage of DSLR video is that it uses the full sensor (allowing Hollywood lower DOF). But Thom Hogan talks like it is a given that the D800 (36 megapixels) subsamples every third line of the Bayer pattern (video). And then resamples that a little smaller. Says the sub-sampling costs two stops of dynamic range for video (ISO 1600 video compares to ISO 6400 still - speaking of D800). Dunno, I've never heard any other mention of that?
Because Large is 100%, Medium is 75%, and Small is 50%. The 75% would be a sub-sampling problem, and sub-sampling can cause aliasing (moire) and loss of dynamic range. Why not resample?
Either way, smaller is a loss of resolution... but that is speaking of a 100% view. Unless printing murals, we always have to resample (or crop) a 24 megapixel image to use it. Normal monitor screens are at most about 2 megapixels, and an 8x10 print is about 7 megapixels. They cannot show 24 megapixels.
I'd add that Medium size is a choice if you want a smaller file or image, but always leave JPG Quality at Fine. There would seem no point of a lower quality image.
My puzzle is about video format, to 1920x1080. We are led to believe some of the advantage of DSLR video is that it uses the full sensor (allowing Hollywood lower DOF). But Thom Hogan talks like it is a given that the D800 (36 megapixels) subsamples every third line of the Bayer pattern (video). And then resamples that a little smaller. Says the sub-sampling costs two stops of dynamic range for video (ISO 1600 video compares to ISO 6400 still - speaking of D800). Dunno, I've never heard any other mention of that?
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PaulPosition
Senior Member
Is there really a DSLR-advantage to video? I mean, except for the Canon+MagicLantern crowd who get "raw" video and/or hacks such as dual-iso for noisy-but-wiiiide-dynamic-range shoots?
ISO might be only 1600 on D800 video, but that still beats the tiny camcorder sensors. Plus we've got lenses that cost x times more than the entire camcorder.
I have this Canon R300
Canon VIXIA HF R300 Full HD Camcorder 5978B001 B&H Photo Video
which retailed near $300, and I paid $160 direct from Canon for refurbished, closeout I think.
It has a 1/4.85 inch sensor, which I think is about 3x2 mm size. 3x2! It has a 2.8mm lens (zooms to 32x optical!).
Seems very adequate. The D800 is a little better quality images, at least at ISO, but less convenient to use. Except D800 can at least control shutter speed and aperture.
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