Low End DSLR: digital photography on a budget

February 17, 2006

The Megapixel Myth

David Pogue recently posted some interesting insight from a reader regarding just how many Megapixels we need in a camera. In a previous column Pogue quoted Chuck Westfall of Canon’s camera marketing group as saying, “Seven- and eight-megapixel cameras seem to be more than adequate. We can easily go up to a 13-by-19 print and see very, very clear detail.”

His reader wrote in to agree, stating that, “Round about 6 megapixels was always going to be a tipping point, because at that density, the average person won’t see any difference in quality when using a standard lens and printing at reasonable size.” This agrees with what Ken Rockwell has been saying for some time. In fact Rockwell goes so far as to say that for the average person, “a 3 MP camera pretty much looks the same as a 6 MP camera, even when blown up to 12 x 18!”

So why would we want more pixels?

As Pogue’s reader points out, quadrupling the number of pixels is effectively doubling the zoom of the camera. With light sensitivity and resolution doubling every two years, there is a doubling of the zoom factor every four years. We could be seeing the gradual replacement of mechanical zooming on even high quality cameras.

The whole idea of digital zoom will take on new significance. Where cameras now use smoothing algorithms to interpolate pixels that are not there when they use digital zoom, in the future a 24 megapixel camera will be able to “boast” a 2x digital zoom at the equivalent of 6 megapixels. Right now such a camera would have no place in a Low End DSLR site. However, it might not be too long before such a camera is the low end.

Posted by Mark in: Equipment | Lenses | Comments (4)

Comments

It’s less about megapixels, and more about the quality of those pixels. My first DSLR was the Canon D30. I still have the body, and use it as a backup to my 20D. It is a 3MP camera, but because Canon makes pretty good glass, and the CMOS sensor they used was very high quality, the images were great. With my D30, I was able to produce 10” square (printed) photographs, and they were sharp and beautiful.

When you have a high pixel density, you have the potential for leakage… current that spills from one element of the CCD/CMOS to the surrounding areas. Many smaller cameras boasted a much higher MP rating, but the sensor was crap, so they didn’t come out as well.

Posted by: CM Harrington on February 17, 2006 08:37 AM

You’re absolutely right - most consumer level 8MP cameras have small CCDs with very small pixels. DSLRs, on the other hand, have much larger CCDs so the pixels are larger, and can gather more light and faster. So the quality of the resultant images is much higher.

We’re paying for more than jsut the ability to change lenses!

Posted by: Mark Newhouse on February 18, 2006 05:59 PM

I do enjoy the benefits of extra megepixels to crop out details which you otherwise can’t capture. I’ve also noted that a 50% view of a 6-8MP shot will look sharper than a 100% of a 4-8MP.

I’ve never liked interpolation and don’t see use shy away from using our zooms for a while; though I could see benefits for compact systems & phone cameras for such an idea over a mediocre lens system.

Posted by: frank d on March 14, 2006 06:42 PM

You’re right—we won’t be seeing this technique replace/enhance zooms on DSLRs for quite a while, but you make an interesting point about how it would make sense to use it for cell phone cams.

Posted by: Mark Newhouse on March 15, 2006 10:40 AM

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