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Welcome to this week's edition of the Computer Kindergarten Newsletter.
Today is Sunday, May 13, 2007
To all the Moms, Happy Mothers Day!!
In this Issue:
Special Feature: Photography Jargon
Tips & Tricks: Set Up Periodic Virus Scans
This Week's Topic: Canned Air
Websites of Interest: Mothers Day; BBC Interviews; Optical Illusions; Ocean Explorer
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Special Feature: Photography Jargon
From Worldstart. Used with permission.
If you’ve recently bought a new digital camera or if you're planning on buying one in the near future, these technical terms will help keep you better equipped. The best buyer is one who is better informed and nothing is a better beginning than knowing what some of the terms mean when it comes to understanding the basic settings on your camera. Let's begin!
Pixel
The word "pixel" stands for picture element. What you see on the LCD viewfinder of your camera or on your PC monitor is a bunch of pixels. A general rule of thumb is that the greater the pixel count, the better and sharper the image. A greater pixel count means the image can be viewed at its native resolution. That is, the resolution it was captured at, with less loss in visual detail.
Megapixel
The megapixel (MP) rating of a camera represents the resolution (in millions of pixels) that the camera is capable of producing. A six megapixel camera’s CCD sensor would be capable of capturing an image containing up to approximately six million pixels.
Sensor
The digital image on your digicam is produced by the camera’s sensor. The sensor is basically a unit that measures the brightness of each pixel. The sensor unit consists of millions of tiny pixels in an array like fashion. Each pixel is tasked with capturing photons and each pixel can capture a certain number of them. The photons collected by each pixel are converted into an electrical charge via a photodiode. After this, the electrical charge needs to be amplified and then converted to a digital charge to a digital value. That is done by the ADC (Analogues to Digital Converter).
CCD and CMOS
There are two types of digital camera sensors. The most common are CCD (Charge Couples Device) sensors, used in nearly all cameras. CMOS (Complementary Metal Oxide Semiconductor) sensors are relatively faster and smaller than their CCD counterparts and they are found only on some select high-end cameras.
Optical and Digital Zoom
It’s simple. Optical = good. Digital = not so good. Optical zoom uses the camera optics. That is, the lens, to bring the subject in for a closer focus. This is the actual way a zoom should work and even film cameras use this sort of zoom. Digital zoom is a "simulated" zoom, which means the sensor crops the image and then enlarges the cropped portion to the size of the original. This is called interpolation and it results in image quality loss. Therefore, digital zooming has nothing to do with camera optics.
Noise
Noise is nothing but unwanted pixels. It's like the presence of color speckles where there should be none. For example, instead of a blue sky, you notice faint pink, purple and other color speckles among the otherwise blue color. One of the major differences between a consumer digital camera and a digital Single Lens Reflex (dSLR) is that the former produces images with a lot of noise when using high ISOs and long exposure times and the latter is practically noise free.
Pixelation
This refers to the graininess you sometimes see in an image, which can be caused by either a weak pixel fill rate, improper geometry of the individual pixels or other factors, like color accuracy, noise and unnecessary storage of pixels. It’s an unwanted element in digital photography.
The ISO Rating
This value represents the sensitivity of the image sensor to the light present in a scene. The higher this figure is (64, 100, 200, 400, 800 and higher), the better equipped the camera will be to take good photos in low light conditions.
White Balance
White balance is a camera setting that can be tuned to adjust the tone of the color in the resultant output. Its objective is to make the scene as neutral as possible, as far as, white goes. This way, the white actually appears white without hues. A camera will display a white object with different hues under yellow, fluorescent or natural light. This is a naturally occurring phenomenon that can spoil photographs with even the best cameras. It all happens if the white balance is not set correctly. Cameras have settings, such as Auto, Incandescent, Fluorescent and more for the white balance.
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Tips & Tricks: Set Up Periodic Virus Scans
Most antivirus programs have protection that should prevent a virus from getting onto your computer. It is still a good idea to periodically scan your computer just in case something was missed by the automatic protection.
To setup a scan schedule, open your antivirus program and look for an option such as disk scan, full scan, or system scan (all antivirus programs differ in the command names).
When scheduling virus scans, choose a day and time when your computer will be on but you will not be using it.
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Today's Topic: Canned Air
Question: My son said I should use canned air to clean out my keyboard. Can you give me information on that, in particular whether it is safe or not to use.
Answer:
Canned air is air that is in a pressurized can. It is very useful in cleaning out debris in hard to reach places such as the inside of computers and between the keys on keyboards. The can comes with a long straw that can fit in tight places and shoots out a blast of air, which blows out any dust and dirt.
The air used for canned air is made up of nitrogen and other harmless gases. It is ozone safe.
While canned is safe to use on your computer, you do need to buy the non-flammable kind. If a flammable gas mixes with voltage from your computer, it could flame up. read the label closely; it will say whether it is flammable or not.
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Websites of Interest:
Mothers Day
Visit our website for many fun and interesting links for and about Mom.
http://computerkindergarten.com/html/mom.html
BBC Interviews
Visit this website for fascinating interviews with actors, painters, religious thinkers, and many more famous people.
http://www.bbc.co.uk/bbcfour/audiointerviews/
Optical Illusions
This website has some pretty interesting optical illusions and explains why and how they work.
http://web.mit.edu/persci/gaz/gaz-teaching/index.html
Ocean Explorer
Anyone who appreciates the beauty of the ocean will love this very cool site. Read information about current explorations and marine expeditions, and see some amazing photographs and images.
http://www.oceanexplorer.noaa.gov/ |
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