Why 1.5 Megapixels is Enough

Dots Per Inch is a useful measure of relative resolution. But if you don't know the image size in inches or some other measure of size, then the amount of dots per inch doesn't mean much. That's why DPI is used in conjunction with scanner Specifications, because you know that the size is going to be 3.8 by 1.7 inches!

Different resolutions are used for different purposes. 72 or 75 DPI for screen viewing; 250 for digital photography and 300 dpi for printing. See how this is a nice comparison, yes, you can get away with 50 less pixels per inch in your photographs than would be required for A4 printing, this is because of the physical size of the photo!

Dots Per Inch specifies how much information is resolved in a picture, whereas the number of megapixels is usually used to describe the total output size (in pixels) of an image.

Example: I want to reproduce the standard photograph size. This would be 6 by 4 inches. Digital photography requires a minimum of only about 250dpi, So: 6 * 250 = 1500 and 4 * 250 = 1000, so you need an image sized about 1500 * 1000 pixels (about 1.5 megapixels). Thus you can get a perfectly good standard print from a 1.5 megapixel camera!

If you take a photo twice, one at 5 and the other at 1.5 megapixels, than ask your self which one looks "better"? They will both look reasonable because your computer generates colours such that the image looks better than it really is; if you were to print both as a 6 by 4 image, they will look identical, because your printer can't generate more than 300 dpi so the "better" image is effectively reduced in quality anyway. This example demonstrates how it is possible to literally waste memory, ie for everyday use the additional memory required for the other 4 megapixcels gives you no real benefit!

This is quite good because a 36 Megabyte media card can store 50 to 65 images at 1.3 megapixcels but only 8 to 10 at 5 megapixcels, so unless you are planning on getting your images printed larger than 6 by 4 there's no real advantage to the full 5 megapixcels.

Now we have established that a 1.5 megapixel camera will produce a 6 by 4 inch standard photograph, that is, it will generate a resolution such that each pixel is simply reproduced "as is", we come to the more interesting issue of enlargement.

If you wanted to print your 6 by 4 inch image as a 10 by 8 photo (which would normally need the full 5 megapixels), there would not be a sufficient number of pixels for the additional surface area, so we now need to scale up the existing pixels by "resampling" the existing pixels, a process which estimates how the "missing" pixels should appear, and fills them with the appropriate "colour". A 25% resample

I am the website administrator of the Wandle industrial museum (http://www.wandle.org). Established in 1983 by local people to ensure that the history of the valley was no longer neglected but enhanced awareness its heritage for the use and benefits of the community.

---

Digital Camera Bags - Purchasing and Using

Some compact cameras are small enough to fit in your... Read More

Let Those Digital Photos Out! (You Don?t Have To Print Them Yourself)

What have you done with the photos you've taken with... Read More

Start a Photography Business from Home

Anyone with the right camera equipment, and the necessary skills... Read More

Photography - Rules of Composition

Composition is defined as the combining of distinct parts or... Read More

Digital Image Files ? Megapixels, Megabytes, or DPI?

When I promised readers that I was going to do... Read More

Digital Cameras vs. Film Cameras- the debate goes on

One of the biggest debates in the photography world is... Read More

Everybody is Fixing Their House or Apartment Up These Days. Use That Digital Camera to Capture

That's right, you go through all the trouble of making... Read More

Panasonic Digital Cameras - The History Behind Their Cameras

Panasonic is a world-renowned consumer electronics company today. Its digital... Read More

The Naked Truth on Shooting Nudes

There are major obstacles to overcome to get into nude... Read More

Exposure Compensation

The digital camera is in reality a great possession with... Read More

Transfer The Digital Camera Images To Your Computer

There are a few very important tasks associated with using... Read More

7 Things You Must Do If You Want To Make That Perfect Camera Shot

Saturate yourself with your subject and the camera will all... Read More

Christmas Rush this Holiday Season to go to Digital Photography

So you have rushed out into the malls in a... Read More

The Well-Dressed Photographer - Summer

Outdoor photographers shoot year round. That includes the hot summer.... Read More

Becoming A Digital Artist On A Budget

So, you want to become a digital artist but paying... Read More

A Guide to Disposable Digital Cameras

Disposable Cameras (also called single-use cameras) first came on the... Read More

Take Spectacular Nighttime Photos with your Digital Camera - Part I

Night photographs express a special something that cannot be seen... Read More

Review of the Photek Product Shooting Tent

Here's the challenge. You have to photograph small items for... Read More

Photography Contest - a fun and rewarding experience

Do you like to take photos? Are you always standing... Read More

How to Take Better Photos of Your Baby or Toddler

Every Mom wants to take great photos of their babies... Read More

Wildlife Scouting Cameras

For years I wondered how big the bucks were that... Read More

Digital Cameras Demystified

Demystifying Digital Camera JargonWant to buy a digital camera but... Read More

Get Closer to Your Subject

Almost any shot will look better if you take two... Read More

Photography Poses ? The Missing Ingredient

You've read all the "best digital camera" articles, got the... Read More

What You Need To Buy A Digital Camera Wholesale

Digital cameras are available in several price ranges today. They... Read More

Digital Camera Memory Cards

A digital camera accessory you should purchase is a spare... Read More

How to Take Great Photos of Your Child

Children are naturally photogenic. Ive worked in studios and children... Read More

Tips for Purchasing a Digital Camera Lens

Your lens is an essential element to good photographs. It's... Read More

Black and White is Beautiful

Think about Laurel and Hardy for a moment, or Charlie... Read More

Photography - Things to Consider Before Buying a Camera

Before you are able to take the kind of photos... Read More

Digital Camera Metering

Looking at the most intricate details of the digital camera... Read More

Using Film Speed Effectively (Black & White Film Thoughts)

It's hard to find sometimes but it's making a resurgence,... Read More

8 Simple Tips for Taking Great Baby Photos

Taking pictures of your new baby is a great way... Read More