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false_Aesthetic
28-Feb-2012, 08:33
So if I understand things right, Nikon has generally opted to take a full-frame sensor and leave the individual pixel size relatively large whereas Canon take a full-frame sensor and makes the pixels smaller thereby increasing megapixel size.

Can anyone explain the logic behind each choice? I'm assuming that each has its trade-offs.


I think I get the basics but I'd love to be able to explain this a bit more eloquently.

Thanks

Peter De Smidt
28-Feb-2012, 08:59
So if I understand things right, Nikon has generally opted to take a full-frame sensor and leave the individual pixel size relatively large whereas Canon take a full-frame sensor and makes the pixels smaller thereby increasing megapixel size.



Nope. Nikon's top pro dlsr, the D4, is 16mp and Canon's is 18.1 mp. That's not much of a difference. And nikon's new D800 is 36mp, and it costs about half of what a D4 does.

More megapixels = potentially higher resolution and the ability to make larger prints at a higher quality, assuming that the lenses and apertures used take advantage of the increase. Downsides are bigger files, slower shooting, and perhaps not as much dynamic range.

false_Aesthetic
28-Feb-2012, 09:17
Both Canon and Nikon opt for smaller mp for their pro cameras. Why?

And why does it seem like Nikon hasn't concentrated on increasing the MP size the way Canon has (until the D800).

Peter De Smidt
28-Feb-2012, 09:27
Because those cameras are all about speed and low light ability. They are primarily sports and photo journalist cameras. The D800 is aimed more at landscape and studio photographers.

Mike Anderson
28-Feb-2012, 09:52
....
And why does it seem like Nikon hasn't concentrated on increasing the MP size the way Canon has (until the D800).

I think in the recent past Nikon's marketing position is that lower noise at high ISO is more important than a high pixel count. But as technology rapidly advances and both a noise decrease and a pixel increase is feasible, well I guess everyone has to rethink what the best balance is.

Nathan Potter
28-Feb-2012, 11:23
Pixel size has to do with how much light you can capture per pixel. The larger the pixel the more light you can capture (larger signal) while the noise floor remains the same (well similar). But the larger the pixel the poorer the resolution.

So large pixel - higher signal strength, better signal to noise ratio, poorer resolution.
Small pixel- lower signal strength, poorer signal to noise ratio, higher resolution.

The disadvantages of pixel size reduction can be offset by a number of sensor design and fabrication techniques such as microlens use at each pixel and interpixel light shielding, etc. etc. as hardware implementation. Even software can be configured to off set the disadvantages of pixel reduction or size increase - such as demosaicing.

Overall the performance tradeoffs are very complex when assessing the difference between larger and smaller pixel arrays. There are a considerable number of tricks that can be employed even when designing the solid state sensor involving such things as the strength and shape of the electric field in the active device depletion region - again - etc. etc.

It's almost a can of worms, but a skilled designer can pick out the choicest ones!

Nate Potter, Austin TX.

Gene McCluney
28-Feb-2012, 12:08
Uh, Nikons NEW full-frame DSLR, newer than the one mentioned above, is 36 mpx. So pixel density is higher. The Nikon mentioned above is the Sports version which has ability to shoot more frames in rapid succession.

Greg Miller
28-Feb-2012, 13:04
Nikon's new D4 is 16 megapixels and provides high pixel quality, low noise at high ISOs, and a high burst rate (frames per second). Nikon's new D800 is 36 megapixels, has relatively more noise at high ISO (because of the smaller pixels (photo sites) and a lower burst rate than the D4. 2 different pro cameras aimed at 2 different types of photographers.

Interestingly enough, Nikon reps are saying that the D800 has better dynamic range and at least as good high ISO noise than the D3/D700 (12 megapixel cameras). The D3/D700 were considered the best image quality sensors available when they hit the market about 3.5 years ago. So if the reps statements are true, the D800 will be a remarkable camera. Also interestingly, I frequently get comments about the amount of detail in prints from my relatively low resolution D700. So megapixels only tell a part of the story. The quality of the pixels (generally better when the photo sites are larger), subject matter, and photographer technique (in the field, in Photoshop, and when printing) count for quite a bit as well.

vinny
28-Feb-2012, 13:42
"The D3/D700 were considered the best image quality sensors available when they hit the market about 3.5 years ago. So if the reps statements are true, the D800 will be a remarkable camera"

hasn't this been the case with every new digital camera canon/nikon has released since the first dslr?

Greg Miller
28-Feb-2012, 13:51
"The D3/D700 were considered the best image quality sensors available when they hit the market about 3.5 years ago. So if the reps statements are true, the D800 will be a remarkable camera"

hasn't this been the case with every new digital camera canon/nikon has released since the first dslr?

No - not really. The D3s (a slightly tweaked D3) is still #6, only surpassed by the four MF sensors and the Nikon D3X. Not bad for 3.5 year technology. So tripling the pixel density and maintaining high ISO noise capabilities is pretty impressive.

Greg Miller
28-Feb-2012, 13:55
Here's a link to the lab, the defacto standard these days, for the sensor rankings: www.dxomark.com (http://www.dxomark.com/index.php/Cameras/Camera-Sensor-Ratings)