Resolution – Does it Matter?

There’s a seemingly never-ending war on at the minute between digital camera manufacturers, and consumers appear to be getting taken in by it all. It’s one of the biggest selling points for a digital camera – the resolution, or in high-street terms the megapixel count. So does resolution really matter?

Put simply, for the average consumer, not really.

There’s plenty of cameras available now which have a resolution of 10-12 megapixels (MP). So are they any better than my Canon 350D, which “only” has 8MP? And what can my big, heavy, expensive camera do that your svelt pocket sized 10MP thing can’t? A friend once asked (referring to my £700 Canon lens) “so how many times zoom is that?”. Well, it’s a 70-200mm lens, so that would probably mean “nearly three”. “Only three? Mine has got 10 times zoom”. So what gives then?

For a quick demonstration, have a look back at my post about the religious pamphlet, dated 31st December. The image of that leaflet was taken using my camera on a tripod (see the post following it) and that produced a picture with quality far better than is necessary for a simply blog entry.

To highlight the difference, the leaflet itself was 4” x 5.5” and I’ve zoomed into a section of the woman’s head. Note that the zoom level is twice normal size: i.e. for every pixel on your screen, that’s two which appeared in the original image. The actual section of print you’re looking at below corresponds to about 0.75” on paper.

Woman's head

The first thing you notice is the grainy-ness of the image (click for a bigger version). That, though, is nothing to do with inadequacies of my camera. It’s actually the camera picking up the way the printing process works. I couldn’t believe it at first either, but apparently so. I had to go back and very carefully examine the original, only to find that there wasn’t anything wrong, but under very close inspection there was the print bubbles as seen above.

So how does it capture such fine detail? Well that’s because the lens is massive compared to all of the standard compact cameras. A bigger lens means more light is captured, which means a better quality photo. After all, that’s what a photograph is: just some light landing on a bit of film (or electronics in this case). Unfortunately, a bigger lens means it’s more expensive and heavier.

There’s also a bit to do with what happens to the light after it hits the electronics. In compact cameras, the camera makes a quick decision on what it deems to be detail that would never be noticed by your average punter and then throws it away. That’s right: at least half of the detail your compact camera picks up in a photo is thrown away before it even appears on the screen at the back of the camera.

There are two reasons for this: so that you can get more pictures on a memory card; plus it means that you can take the card out of the camera, plug it into a computer and you’ve got images. With my camera, it’s a bit different. Instead of throwing away stuff, my camera keeps it all and I go through each image deciding for myself what will look good and what will look bad. Yes, it means I use more memory up per picture and the process takes longer, but I think it’s worth it.

If you’re heading out to buy a camera, don’t be fooled by megapixel count.