image sensor (pixels/effective pixels)

John C Lyons

John C Lyons

Veteran
Hello,

What are the best numbers to compare within the specs of two cameras to see how they match up as far as image quality? Say I am doing a 2 camera shoot and the other camera isn't a DVX, what should I be looking at numbers-wise?

And how do they come up with the pixels/effective pixels for example? Are these important? Canon is pretty open about these numbers (XL1s: 270,000 Gross Pixels, 250,000 Effective Pixels) and I can't find them for the DVX.

So how do I go about figuring them out? And are they a good indication of image quality for a camera?
 
Re: image sensor (pixels/effective pixels)

for the dvx100 these numbers can be found in the tech spec. addendum in the camera manual. for my dvx100e, these values are reported as: 470 kpixels total / 440 kpixels effective. from what
i know, pixelcount is an indication of image quality, but by far not the only one to go on. i.e., if camera A has a higher pixelcount than camera B that does not automatically mean that camera B will deliver an image inferior to camera A. there's a slew of other factors that affect the quality of the final image... among the most obvious here are "optics" and "dsp algorithms"...

cheers,

serra
 
Re: image sensor (pixels/effective pixels)

Pixel count is one of the most misleading indicators of picture quality. Many people brag about their cameras having megapixels, as if that makes for a better picture. The simple fact is, the CCD should have about enough pixels to cover the frame. On pro cameras, like the $25,000 SDX900 or the $15,000 DSR570, you'll find about 500,000 pixels... just about enough to cover the frame.

The XL1 is severely deficient in pixel count at only 250,000 or so. It tries to make up for this by using pixel shift.

Sony's PDX10 has a megapixel CCD. Anyone who's seen the picture side-by-side with the DVX would not say the megapixel CCD was superior! It is severely lacking in low-light performance, and exhibits strong vertical smearing tendencies.

So, pixel count is nearly irrelevant. As long as there's about as many CCD pixels as it takes to fill a frame, that's about all you need. In standard-def video, that means you need somewhere around 350,000 to 400,000 pixels on the CCD and you're good to go.
 
Re: image sensor (pixels/effective pixels)

thanks guys!

sure i know its not the ONLY factor, i just wondered why those #'s for my 100A werent as readily available as they seem for other cameras.
 
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