Why ‘more megapixels!’ doesn’t mean better pix

[steven johnson]

Six megapixel cameras are usually more than adequate for most people. More Megapixels won't necessarily yield better pictures, especially with the newer small cameras. Here's why.

A high megapixel count doesn’t always equate to better image quality. In fact, if camera designers try to cram too many megapixels into a small camera it can actually have the opposite effect.

To keep sizes down, manufacturers place itty-bitty image sensors inside their point-and-shoot models. These small parts perform well within a certain range. But when companies try to raise the megapixel count without increasing the dimensions of the camera, that means the same size sensor now has to do more work.

This leads to larger but less accurate images, says Mr. Gupta. The overburdened sensor can lose sharpness, struggle in low-light situations, and add “noise” (small blotches or odd colors).

Digital SLR cameras are bulkier than sleek point-and-shoots, but the extra room allows for much bigger sensors and often better image quality per megapixel.
http://features.csmonitor.com/innovation/2009/04/22/why-%e2%80%98more-megapixels%e2%80%99-doesn%e2%80%99t-mean-better-pix/

[Stevenmarc]

1. And that's why I have a Sigma DP2 on order

A compact camera with a DSLR sized sensor

[priller]

2. While camera manufacturer's have gotten really good at it

they've still gone crazy with the megapixels. My compact camera is a Canon G9 and I thought it was crazy to have 12 MP (and it has a slightly larger sensor than most compacts). It has noise even at ISO 100, not a lot, but it's there. Then they came out the with G10 with almost 15 MP. Just nuts!

It will be interesting to see what they do with the Micro Four Thirds cameras. I would love to see something in a Rangefinder style with smaller lenses and such. Something like a Leica M8 at 1/4 the price would be nice.

[Tallison]

4. Because MPs are the one spec even the village republican gets

I'd bet that 80% of camera owners don't even know what aperture is.

[dbmk]

3. It is one of the few numbers that can be quantified

Its like the size of the tv-screens. Its the one thing the average consumer can differentiate on.

And if it didn't work (sadly), they prob would not do it. Educating the entire P&S customer base about image quality vs pixel size must seem insumountable and not profitable businesswise. I _think_ they might be approaching the limit though - where they HAVE to develop other parts to the same degree.

Or as in the Sigma case, find a way to put in larger sensors. But even that would take some explaining to the customer base, when they field less resolution than the competitor using a sensor the size of a pinhead.

I think they are afraid to be the first to drop out of this race.

[Tallison]

5. Seriously - I don't think my Macbook and Nikon RAW software

could manage much more than 12 MPs. The computer's two years old, and is already glacial processing 6.4MP RAW.

[flamin lib]

6. There's also aspect ratio to consider.

Most compact cameras are geared to about 1.2 to 1.3 to one ratio. The image is 1.3 times longer than it is high. That's pretty close to traditional formats of 4x5, 8x10, 11x14 etc. It's also very close to the aspect ratio of computer screens and desktop printers. That means there is no "wasted" image area that has to be cropped out to fit those formats. You simply don't need that many pixels to get equivalent quality in an image. Hasselblad, the king of medium format, is 6x6 mm because it's awkward to rotate the camera . . . the focus screen has crop lines to show what image will print on 8x10 paper.

35mm has an aspect ratio of 1.5 : 1, much wider than traditional formats. Same with the wide screen imagery of new high def TVs. It flies in the face of traditional formats like 6x7 mm, 6x4.5 mm and 4x5 inches. I've never liked the 35 format. It just isn't pleasing to my eye. True, it's based on the "Golden Rectangle" that dates back to the pyramids but so what?

That's one of the reasons I shoot 4/3 format; 1.25 : 1. That and blind loyalty to the Olympus brand. The 4/3 format closely matches the aspect ratio of the paper I print to so there are no "wasted" pixels. My 10 mp Olympus is equivalent to 13 mp in the 1.5 : 1 format. Plus it's easier to compose because the viewfinder is much closer to the printed image.

Back in the OM system days I had a 1-10 focusing screen with etch marks 2 mm from the edges so I'd know how much of the image would fit on 8x10 paper.

*Sigh* I miss the OM days. If I could combine all the best features of all the major manufacturers I could ALMOST match the OM system. Give it another 10 years and digital will get there. Maybe.