Digital Cameras - how many pixels do you need?

The cameras buyer tend to fixate on the image size, in particular the number of megapixels. But how do you really need?

Well, that depends on a number of things: If the image on a computer screen or print, how great is the theme to be displayed, and how small it is.

The standard resolution for computer monitors is 72 dpi. This means that you should have 72 pixels on each inch screen. If you have an image to display3 "x 2", then this is 216 x 144 pixels (3 x 72 = 216: 2 x 72 = 144).

For a picture on a standard Blogger blog, but only as much of the width 400 pixels. Although a photo of the landscape is high, 600 pixels, which is still a paltry 0.24 megapixels. If I have a picture to add a text message, there is something greater than this. In other words, every mobile phone, a camera that has enough pixels for your blog.

If you fill the entire screen, (perhaps for a Power PointPresentation) is the most common screen size is now 1024 x 600 pixels, which is still only 0.6 mega pixels.

But if you print a photo at 72 dpi, it will look terrible. The standard resolution for printing is 300 dpi. A postcard-size print is 6 "x 4", or 1,800 x 1,200 pixels = 2.16 megapixels. A standard 10 "x 8" print (slightly smaller than letter size) is 3,000 x 2,400 pixels = 7.2 megapixels. Obviously a 10 or 12 megapixel camera that is easy to do. But a full-size His exhibition print, 24 "x 16" would be a huge 7,200 x 4,800 pixels. That with 34 megapixels.

If you find an affordable 34-megapixel, please let me know. Until someone does, it's probably best to keep the variables that can not print.

Fortunately, this is not the end of the story. You can increase the number of pixels of the image with Photoshop or GIMP with the free program. There are no good as a result of the additional pixels in> Room, but it is better to stick with not enough pixels. The details are a bit 'blurry, though. Even the best algorithm of inflation in the world can not produce parts that fell between the cracks of the detector

300 dpi is the standard, but that does not mean it's set in stone. Some subjects in which there are no details, see the definition much lower in order. Sunsets and clouds, or something out of focus, for example. Some, like water, can also look betterlow resolution, since the effect is similar to soft-focus. Print out the skin under my eyes at 100 dpi, please!

And then there are the issues that seem much better at 400 dpi or higher resolution. Long grass and animal skins are particularly demanding. Do not you see it at 300 dpi is more bad news they are looking better at 400 dpi or more. (In the same way as a print from a negative 35 mm looks OK, but a larger negative looks better. It 'a simple reason whyAnsel Adams was wearing a heavy camera and tripod plate in Yosemite.)

And finally there is the question of how small it is. Some people do not mind blurry prints, as well as some people do not mind a tilted horizon of the sea of ​​ten degrees. But if you intend to sell your photos, I suggest you should be picky when your customers.

So, if your photos just go on the Internet, the number of pixels in the camera is not really important. If you only wantSmall items, is to make a small camera. But if you have ambitions to exhibit their work, you want every pixel you can afford.