Digital sensors and storage cards have improved dramatically over the past decade. What used to be state of the art is now old school. New digital cameras and even camera phones can take 10 Megapixel photos, where as a decade ago 3 Megapixels was considered top end. The question is, "How many Megapixels is enough?"
Let's first address the fundamentals of digital imaging. The terms pixel and megapixel should sound familiar to most people, but what are they? A 'pixel', short for picture element, is a single bit of information about the image color. Picture a blue dot. That dot represents a pixel. It could be any color at all. Now picture a tic-tac-toe board, with three rows and three columns for a total of nine boxes. Mentally place a blue dot in each spacenow you have nine pixels.
If you continue to increase the size of your tic-tac-toe box, you can see the image size quickly increases. A megapixel, represents one million pixels, or an image that is 1000 rows by 1000 columns with each cell containing a single bit of information. While 1 million pixels sounds like a lot, a 1000 x 1000 pixel box is much easier to visualize.
So what kind of image can you make with a million pixels? It depends how you produce the image. If the image will be displayed on a computer screen, the resolution of your computer screen will determine how large the image is. Suppose you have a photo a friend sent you that is 320px x 240px large. If your computer screen is set at 800px x 600 px (a common size) that image will fully appear on your computer screen without having to scroll around. An image size of 320 x 240px or 600px x 400px are nice sizes for viewing on a computer or webpage.
What about viewing the image on printed paper? The ability to include far more detail on a printed image has to do with the resolution of your printer as well as the incredible detail the human eye can see. Your 320 x 200 pixel image would print out about 1.6 inches across and 1 inch high if you are printing at 200 dots (pixels) per inch. This is also known as "DPI" (dots per inch) and is considered a minimum resolution for good picture quality. Suddenly, that nice looking image from facebook looks very very tiny when printed from your photo printer.
How many pixels does it take to print a good quality 8 x 10 " photo? If you use the minimum resoluton of 200dpi, simply multiply the inches by the dots per inch to get total dots (or pixels) per image. 8 x 200 is 1600 and 10 x 200 is 2000. So you'll need an image size of 1600 x 2000 or 3.2 million - 3.2 megapixels (MP). Most people would love to frame a nice 8 x 10" glossy print from their favorite vacation snapshots...but if it only requires 3.2 megapixels to print an image of this size, why all the hype about 10, 12 or even 14 MP cameras on the market today?
Most of us typically like to take photos that we've taken and zoom in, crop or otherwise 'enhance' the image. Zooming or cropping naturally removes some of the information and effectively reduces the image size by focusing on a smaller portion of the digital information. This is one reason that a few more megapixels will help you achieve nicer looking printed images. But at one New York City photo gallery, 13 x 19" professional images being sold were taken with a Nikon camera that had "only" a 6MP sensor. (source: Ken Rockwell dot com)
Consider this as you are shopping for your next digital camera, and you can put your money towards other features that will help you capture great looking images you'll be proud to share wth family and friends. Don't get distracted by massive megapixels in the specs of your next purchase.
Let's first address the fundamentals of digital imaging. The terms pixel and megapixel should sound familiar to most people, but what are they? A 'pixel', short for picture element, is a single bit of information about the image color. Picture a blue dot. That dot represents a pixel. It could be any color at all. Now picture a tic-tac-toe board, with three rows and three columns for a total of nine boxes. Mentally place a blue dot in each spacenow you have nine pixels.
If you continue to increase the size of your tic-tac-toe box, you can see the image size quickly increases. A megapixel, represents one million pixels, or an image that is 1000 rows by 1000 columns with each cell containing a single bit of information. While 1 million pixels sounds like a lot, a 1000 x 1000 pixel box is much easier to visualize.
So what kind of image can you make with a million pixels? It depends how you produce the image. If the image will be displayed on a computer screen, the resolution of your computer screen will determine how large the image is. Suppose you have a photo a friend sent you that is 320px x 240px large. If your computer screen is set at 800px x 600 px (a common size) that image will fully appear on your computer screen without having to scroll around. An image size of 320 x 240px or 600px x 400px are nice sizes for viewing on a computer or webpage.
What about viewing the image on printed paper? The ability to include far more detail on a printed image has to do with the resolution of your printer as well as the incredible detail the human eye can see. Your 320 x 200 pixel image would print out about 1.6 inches across and 1 inch high if you are printing at 200 dots (pixels) per inch. This is also known as "DPI" (dots per inch) and is considered a minimum resolution for good picture quality. Suddenly, that nice looking image from facebook looks very very tiny when printed from your photo printer.
How many pixels does it take to print a good quality 8 x 10 " photo? If you use the minimum resoluton of 200dpi, simply multiply the inches by the dots per inch to get total dots (or pixels) per image. 8 x 200 is 1600 and 10 x 200 is 2000. So you'll need an image size of 1600 x 2000 or 3.2 million - 3.2 megapixels (MP). Most people would love to frame a nice 8 x 10" glossy print from their favorite vacation snapshots...but if it only requires 3.2 megapixels to print an image of this size, why all the hype about 10, 12 or even 14 MP cameras on the market today?
Most of us typically like to take photos that we've taken and zoom in, crop or otherwise 'enhance' the image. Zooming or cropping naturally removes some of the information and effectively reduces the image size by focusing on a smaller portion of the digital information. This is one reason that a few more megapixels will help you achieve nicer looking printed images. But at one New York City photo gallery, 13 x 19" professional images being sold were taken with a Nikon camera that had "only" a 6MP sensor. (source: Ken Rockwell dot com)
Consider this as you are shopping for your next digital camera, and you can put your money towards other features that will help you capture great looking images you'll be proud to share wth family and friends. Don't get distracted by massive megapixels in the specs of your next purchase.
About the Author:
While researching your next digital camera purchase, read Adrian's reviews on Olympus XZ 1 Review and learn why the neat little Olympus XZ 1 should have a place in your camera collection.. Free reprint available from: Megapixel Overload - How Many is Enough For Your Next Digital Camera?.
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