|
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.
|
RELATED ARTICLES
Stitching Memories Sometimes, usual photographs look so common and boring. Converting your pictures into charcoal or oil painting is a welcome change but then, a lot of people have been into these crafts already that there are times when these portraits too, look clichéd. There could also be a time that a charcoal or oil painting of your photo does not look exactly the same as your original photograph. I have been a witness to several charcoal portraiture failure. Have you ever had your portrait done in charcoal in which the result didn't actually look like your image? Disposable Cameras for Weddings Disposable wedding cameras (also called single-use cameras) will never replace a professional photographer, of course. But they could save money on the overall photo budget, provide memorable fun for you and your guests, and occasionally turn up a priceless casual shot. Digital Camera Memory Cards A digital camera accessory you should purchase is a spare memory card. Most cameras are sold with a 'starter' memory card that is usually a low capacity card that's enough to take a few sample photos on, but not enough for day-to-day use. Types of Digital Cameras If you are in the market to purchase a digital camera, you have surely seen several different types of cameras. It isnt exactly clear what the differences between the types are, and it can be confusing trying to choose the digital camera thats right for you. In this article, we wil discuss the different types of cameras so that you can better understand what to look for in purchasing a digital camera. 9 Tips For Taking Great Digital Photos Introduction Wildlife Scouting Cameras For years I wondered how big the bucks were that were roaming our property in the dark of night. After all, I knew that monster bucks had to be eluding me during the daylight hours only to roam the woods at night. In an attempt to reveal these mysterious nocturnal monsters I purchased a scouting camera in 1996. Disposable Underwater Cameras Disposable digital and film cameras (also called single-use cameras) provide a cheap and easy alternative for photographers. They offer an option for times when you don't want to risk your expensive equipment but you do want to take some photographs. For example, what could be a scarier combination for a photographer than an expensive piece of camera equipment and water? While professional underwater photographers (or serious hobbyists) are willing to spend a lot of money on their underwater cameras, what about the rest of us? Disposable underwater cameras offer an inexpensive alternative. After all, we may only want to take pictures one time on a snorkeling vacation. Why should we have to buy or rent a lot of expensive equipment? Who Had The Better Brushes Leonardo or Michelangelo? Ordinary photos of dull subjects do actually sell, but the dramatic shots generally have an unusual element that makes them stand out from the crowd. They are well-composed and they carry no excess baggage. Video Camcorder Formats and Media There are way too many tape, disk and stick formats out there: Creating Printable Photo Greeting Cards STAY CONNECTED WITH FAMILY AND FRIENDS. Digital Film Processing is Really the Only Option for Truly Quality Prints Digital photography has taken off like wildfire these days, primarily due to its ease and quality in its digital film processing. With a good digital camera, it's as though you're using the very best Kodak film for every single one of your digital photos. Moreover, digital film processing can be done from the comfort of your own home with the right digital film processing software or with digital photo developing online. Memories That Get Lost How many people have pictures in a shoe box? In a drawer? Inside a book? Sitting in the garage? Review of the Photek Product Shooting Tent Here's the challenge. You have to photograph small items for Ebay or for clients' brochures. Lighting them can be challenging. Small reflective items usually exhibit specular highlights that must be controlled. If you add a product/shooting tent to the equation, your job is made dramatically easier. Diffusion & Softening of Digital Photography Images Like many people who've made the switch from film cameras to digital, I've discovered that the lens tools I once used so effectively on my cameras to soften, diffuse and vignette my images for quality "finished" professional results won't do for digital what they did for film. A Guide to Underwater Cameras There are two types of underwater camera systems: an ""amphibious"" camera, which is a self-contained waterproof system, and an SLR land camera with waterproof housing. Amphibious systems are small, compact, and easy to travel with, while SLRs offer more advanced features, such as auto-focus, advanced exposure control, and through-the-lens viewing. How Can I Preserve My Lifetime of Memories in Photographs? Like most folks you have probably have organized and sorted your photos atleast once. The problem is they never seem to stay organized no matter how hard you try, and even if they do they seem to lack that original impact that they had shortly after you took them or if they do, you never drag them out until sadly, someone passes on. Studio Photography and Digital Backgrounds The article given here was written for Adobe Photoshop 5,6,7,CS, and Adobe Photoshop Elements 2 and 3. How Many Megapixels Do We Need? Are you having megapixel envy each time you walk by the camera section of your favorite electronics store? So do I. But, do we really need more and more pixels? The answer depends on what we intend to do with the images. First, a quick definition of megapixel: Imperfect Photos And How You Can Fix Them So your picture came out less then perfect. Blemishes or wrinkles, red eyes and wrong color balance - you can fix it all without having to learn or pay for Adobe Photoshop. Try these tools instead. Digital Imaging Explained Digital Imaging is a process where an electronic photograph, scanned document, or image is converted into a series of electronic dots called pixels. Pixels is an acronym for "picture elements". |
|
Copyright © 2006 Advancing Women/font> |