As digital camera’s gained popularity, there was a battle among the various camera manufacturers to gain as much market share as they could in as little a time as possible, and one of the tactics used to accomplish this, was to offer bigger and better image sensors with more and more pixels, and so began the megapixel wars.Naturally, ‘bigger’ appeals to our ‘more is better’ instinct, and it also appealed to basic common sense because who can argue that an 8 megabyte sensor won’t produce a better picture than a 6 megabyte picture, and so we allowed ourselves to believe that we had to get more megapixels. But follow this argument – there are only two things you can do with a digital image. You can view it on a computer monitor or send it to a printer.

To view an 8 megapixel image on a screen, you would need in the order of a 36 inch monitor. Yes, you could scale it down to fit your actual monitor, but it would still be a scaled down image. So what was the point of having such high resolution?

When it comes to printers – frankly, the printer really doesn’t care what the resolution of the image is because the final image (with limitations) is only as good as the printer’s resolution, and print quality is determined by dpi (dots per inch). A 1440 dpi printer will produce a significantly better picture than a 720 dpi printer. The 1440 dpi printer will even produce a better picture from a 6 megapixel image than a 720 dpi printer could make from an 8 megapixel image. Of course there is a limit to when print quality falls off. For example – consider a 6.3 meg image. This is 2048 by 3073 pixels. If we wanted to produce an image that was 5 by 7 inches, then the resolution would need to be set at about 400 ppi (pixels per inch). This is calculated thus – 2048/400=5.12 and 3072/400=7.68. As you can see there will be a bit of cropping, but you get the picture – no pun intended. 400 ppi is more than adequate for any photo-quality printer in the range of 1440 dpi resolution. When we move up to an 8 by 10 inch print, then 2048/250=8.2 and 3072/250=12.3. 250 ppi will work, but as you can see 250 ppi is far less than 400ppi – the larger the image, the smaller the ppi.

Many photo experts agree that this limit should not be less than 300 ppi. That is, to realise the maximum performance from a printer, the image resolution must not fall below 300 pixels per inch. I beg to differ – in fact I regularly print 12 by 18 inch prints from 6.3 megapixel images. I perhaps would not care to go over that limit, but the quality at this size is incredible. Why? Because I have an incredible printer.

So, do not get yourself caught up in the megapixel war. Don’t trade in or give away your 4 megapixel camera for a 5 megapixel or even an 8 megapixel camera unless you have a very good reason to do so. Remember – it was less than a decade ago that 2 megapixel SLR (Single Lens Reflex) cameras were all the rage!