Debunking the Megapixel Myth

Back in 2012, just when we thought the Megapixel Race was over, Nokia released the 41 Megapixel 808 Pureview. 41 megapixels seemed quite impressive for a phone camera, and still is quite impressive. Apparently that wasn’t enough to save the Nokia 808 from the Symbian jinx. I mean, who puts 41-megapixel Carl Zeiss lens on a dying OS?

Fast forward over a year later and Nokia are about to release another 41 megapixel camera phone – the Nokia Lumia 1020 – this time running on the Windows Phone 8 OS.

I think the design is pretty slick, considering how much power those lens behind pack. The Nokia Lumia 1020 is due for launch on July 26th, exclusively on AT&T in the US. But I’m not here to do a pre-release review, I am not worthy. My only aim here is to debunk the myth that megapixels are the ‘be all and end all’ of image quality.

What really is a megapixel?

An 8 megapixel phone camera basically means that the image sensor captures a resolution of 3,264 pixels (across) by 2,448 pixels (downwards). Multiply those 2 figures and you get 7,990,272 which is approximately 8 million – 8 megapixels. In the same way, an image sensor that captures resolutions of 2,592 X 1,944 pixels will produce 5,038,848 – 5 megapixels.

While a higher number of megapixels is definitely instrumental to producing quality images, the number of megapixels is only one of the many factors that determine the quality of an image. There are many 8 megapixel phone cameras out there that take terrible photos in comparison with their cheaper 5 megapixel counterparts.

What other factors matter?

The size of the sensor, size of individual pixels, the quality of the lens, shutter speed and imaging processing software are amongst many other factors that determine the quality of a digital camera.

For example, the HTC One ‘Ultrapixel’ phone camera is just 4 megapixels. Yes, 4 megapixels. This is because, the size of its pixels are way larger than the average pixels you find in any other phone camera. So each pixel occupies more space on the image sensor. Consequently, the image sensor takes in more details, resulting in image quality that easily levels with a lot of 8 (and even 12) megapixel phone cameras out there. And it’s only just 4 megapixels! It isn’t about the megapixels alone!

How many pixels is too much?

A typical HD monitor can only display a resolution of 1920×1080 (2 megapixels). So in theory, 8 megapixels already seems like overkill for the average computer user.

If all you want is to view photos on your computer, share on Facebook/Twitter or upload on your blog, you really do not need more than 3-5 quality megapixels. Note the use of “quality”.

As stated earlier, most monitors can’t even display more than 2 megapixels resolution. Which means that after Facebook crops your uploads, you usually end up with a sharp 1 megapixel image at best.

Even for the enthusiastic printer, a well-shot 8 megapixel image is capable of producing professional looking 8 x 10″ prints – about the size of the standard N50/N80 photos you snap at weddings and owambes. Again, note the use of “well-shot”.

And don’t forget memory space. More megapixels means more MB taken, so what’s the point of having more megapixels than you’ll ever need?

If your end-game is full-scale prints, billboards and the like, we can start talking about 12 megapixels upwards. But even at that, the relevance of over 12 megapixels is debatable. There’s only so much edge more pixels can get you. In short, the camera can only be as perfect as its user.

So why are cameras of over 5 megapixels still being produced for regular users?

You can blame that on the Megapixel Race.

Back in the day, in an effort to tout “superior” specs, phone makers employed ‘guerrilla tactics’. They began to cramp more and more pixels into image sensors, without bothering to increase the size of the image sensor accordingly. So a phone would have an image sensor that cramped 8 megapixels into the same space that was meant for 3 megapixels. All the responsibility of balancing out the unwanted effects, produced by such practices, was pushed to the image processing software. Software that was hardly ever developed properly so you ended up with average looking images. So why not just get it right from the moment of capture?

What’s most innovative about Nokia’s Pureview technology is that it addresses these issues. In order to better accommodate the humongous number of pixels, Nokia increased the image sensor size by a multiple of up to 3 times the normal size of other phone cameras. Coupled with their oversampling technology, the end result is high resolution images with near “lossless” zoom quality.

It would be interesting to see how well the Nokia Lumia 1020 will fare against competition with its 41 megapixel and Windows Phone 8 combo.

Author: Muyiwa Matuluko