megapixels vs ISO

[ken212]

Is it true that the lower the megapixels your camera has that when you use a higher ISO you are likely to get less noise?

[John_Reed]

Is it true that the lower the megapixels your camera has that when you use a higher ISO you are likely to get less noise?The most important thing controlling noise is the size of the sensors in the camera. So DSLRs with much larger sensors than little Point & Shoot compacts can shoot the ISO way up, irrespective of how many megapixels they happen to have. Also, sensors using CMOS technology are cleaner than sensors using CCD technology, so that's a factor too.

And if you take a camera that has, say, 10 megapixels, and select a lower-sized 3 megapixel option, you might think you'd have less noise, but not necessarily true, since the sensors in the resulting 3 megapixel "crop" are no larger than those in the full 10 megapixel sensor array.

If you're trying to compare two cameras or more, what are the cameras?

[AdamW]

Sort of. In general, for a sensor of the same size, after a certain point, the more megapixels the lower the image quality. However, there are too many variables to simply say, "more megapixels equals worse high ISO performance." A larger sensor can fit more megapixels while maintaining image quality. That's why DSLRs can have better image quality than point & shoots, and why full frame DSLRs can have better quality than smaller frame DSLRs. Also, the technology behind a particular sensor, the camera's software, and other variables can make a huge difference.