There are some common words you will see again and again as you delve into digital photography; Megapixel, Resolution and DPI. What do each of these mean?

Megapixels

Megapixel basically means one million pixels. A pixel is a small dot that contains a piece of your finished picture, similar to a puzzle piece. When you put each of these pixels together, they form a picture. Like the picture of marigolds above, you can see that the first one is clear. In the second picture, we have shown how it is formed of millions of tiny pixels. Our eyes process an image as a whole, where as a computer and a digital camera break each image up into pixels.

The more megapixels per image, the clearer and sharper it becomes. Digital cameras today range anywhere from 2 megapixels to 6 megapixels for each picture taken.

These settings will affect the quality of your image and the file size of each image.

Resolution

Resolution refers to the size of the image that your camera will produce. This is normally referred to as megapixels, which we discussed above. You will normally see cameras advertised as having a 1600 x 1200 resolution. To figure out the amount of megapixels that will give you, you multiply the dimensions. For example:

1600 times 1200 = 1.92 million pixels or 1.92 Megapixels. This would commonly be rounded up and referred to as a 2 megapixel camera.

As this amount goes higher, you will notice a much sharper image. We have provided the following examples below. Please look closely at them and you will be able to see the difference each level makes.



1024 x 768 resolution = .78 megapixels




1839 x 1461 resolution = 2.61 megapixels



3200 x 2400 resolution = 7.8 megapixels

DPI - Dots Per Inch

DPI means Dots Per Inch. This is what your printer will recognize when it prints your image. Your computer monitor is configured to view items at PPI, or Pixels Per Inch. This can cause a great disparity when trying to get what looks like a great image on your screen to come out looking just as good on your printer.

An image that has 72 PPI will look fine on your monitor. Each inch of the image will contain 72 pixels. However, when you print that image, it will not be as clear. In fact, it may look choppy and distorted. When you print an image, it will be sized at approximately 25% of what you see on your screen. You will need to have a larger PPI in order to get a printed photograph that is true to size.

The best way to get a true print is to have your image sized at 300 DPI. This will ensure that your image will be the correct size when you print it.

Print Sizes

So what does this all mean in the final analysis? In order to get the best finished product, you will need to have a higher resolution, more megapixels and a high DPI. Unfortunately, this also means extremely large files and very large prints. How can you estimate the size of your images before you are ready to print?

Here is an easy reference guide to get you started:

As you can see, if you wish to get an 8 x 10 print of a certain shot, you will need to have a higher megapixel amount to achieve good results. Otherwise, your finished print will have a coarse, or grainy look to it, instead of being a sharp image.