CẬP NHẬT VIDEO HOT HẰNG NGÀY

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 take the example of a simple tic-tac-toe board to understand what a pixel is. "Picture element" was shorted to "pixel" and represents a single dot of color information. In a tic-tac-toe board, there are nine discrete boxes. Imaging coloring in each box with a blue dot. There would be a total of nine blue dots (three rows times three columns). You can see that the total pixel, or image size, is simply the number of rows multiplied by the number of columns in a rectangular digital image.

If you took your tic tac toe box and made it 10 rows by 10 columns (instead of 3 x 3), then you'd have a 1000 pixel image. Likewise, 1000 rows & 1000 columns equals a million pixels, or one megapixel. You can see how image size can quickly grow by simply adding more rows and columns of information.

Nice image sizes for viewing on a computer screen are 320 x 240 pixels, or even 600 x 400 pixels. If you consider that a typical computer monitor might be set at a resolution of 800x 600 pixels (that's actually a bit smaller than most large computer screens), an image of 320 x 240 pixels will fit nicely inside the computers window without having to scroll.

Now consider taking that great snapshot from your facebook page and printing it on your fancy photo printer. A minimum resolution of 200dpi (dots or pixels per inch) is considered necessary for good quality photos. That 320 x 200 px image now prints out at only 1.6" x 1" on your glossy photo paper. To get a better quality image, you'll need a larger sized image.

With all the hype and marketing of increasingly large sensors on digital cameras, most people believe that 10, 12 or even 14 MP cameras are the way to go for nice prints. However think about what it takes to create an 8 x 10" printed image from a digital photo. If we go by the minimum of 200 DPI (dots or pixels per inch) to create a nice quality printed image, then an 8 x 10" photo requires only 1600x 2000 or 3.2 MP for a nice image. So why do we have all these large megapixel cameras on the market?

One answer is that hardly any of us are happy with the initial snapshot we typically take. It's common to zoom, crop, rotate and otherwise manipulate your digital image after the photo is captured. Therefore the more detail you can record at the time the image is taken, the more manipulation you can do and still have a nice looking printed image at the end of it all. But do we really need camera phone apps that can take 10MP images? Consider that limited edition professional prints of up to 13x 19" are sold at the natural history museum for $650and were taken with a 6MP Nikon Digital Camera. (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.