What is
the Resolution?What you must understand to create quality prints with your digital camera.
A digital image is a rectangle made up of many small squares of color called pixels.
The number of pixels across the width and height of the image is called the resolution.
An image with 640 pixels across the width and 480 pixels high has a resolution of 640x480.
The more pixels in the image file, the higher the resolution.
Many cameras offer a choice of resolutions from 640x480 up to 2400x1800 or higher.
(Example: Nikon Coolpix 2100's mode selection)
The larger the file resolution, the fewer images that will fit on your camera memory card.
Commonly the size of a digital camera image is proportionate to a 4x5.3 not a 4x6.
Here is more details on digital camera's image proportion.
At Doi Camera, we use the most technically advanced equipment available today
to produce beautiful photographs from your digital files.
In order to produce a "photo quality" print, we must print at 300 dpi (dots per inch);
have at least 300 pixels for every inch of the print.
In order to produce a "photo quality" 4"x6" print we need a file resolution of
6"x 300dpi=1800 pixels across the width and 4"x 300dpi=1200 pixels in height.
Therefore we prefer a file resolution of about 1800x1200 or higher
for optimum 4x6 prints.
This resolution would require a 2.1 megapixel
digital camera (1800x1200=2.1 million pixels).
A quality 8x10 print would need an image file
with a resolution of 3000x2400 or higher.
Smaller resolution files can be printed, but the results will be less than optimum.
Below are examples of what a 4x digital print will look like at various resolutions.
Why is it that sometimes a picture-perfect image on a monitor turns out a poor print?
The reason is that a monitor shows an image ALWAYS at its best quality possible,
which is 72 dpi(72 dots per inch). When the dots are less than 72 per inch,
it shrinks down to less than an inch.
When dots are more than 72 per inch, it expands the image,
so the image is always 72 dots per inch on the monitor.
In other words, it FIXes its dpi at 72dpi.
For example, an image of 72 dpi x 72dpi is shown exactly 1x1,
a 150dpi x 150dpi image is 2x2 and a 36dpix36dpi is 1/2x1/2 on a monitor.
On the other hand, the size of a print is determined by YOU,
no matter how much dots it contains,
you tell a printer this is the size I want!.
Let's take an example of 150dpi x 150 dpi image again,
the best result is 1/2 x 1/2 size print, because the printer needs 300 dot per inch.
But you can force the printer to make 4x6 print.
The result is obviously a BAD print.
An image with 640x480 resolution will be displayed on a monitor
as 640/72=8.9 inches by 480/72=6.7 inches, or 8.9 x 6.7 inches in size.
Therefore an image with 640x480 resolution is a good size image to view on a monitor,
email to a friend or use on a website.
Unfortunately, this resolution is too small to make a quality photographic print.
