Manuals and instructions for everything

 why do you need a lens hood

why do you need a lens hood

As is the case with filters, the humble lens hood is something some photographers swear by and some don t want anything to do with. Hoods usually come with certain lenses, or can be bought separately, and can be standard circular types or petal-shaped that latter being arguably more effective as they re shaped to match both the aspect ratio of a sensor and the field of view of a lens though rectangular types also exist. So what exactly is their role? Essentially, a lens hood acts to block out light that the lens shouldn t be receiving, which can contribute to aberrations such as flare, particularly when shooting towards the light. Wideangle lenses, due to their expanded field of view, are naturally prone to gathering stray light, though the reduced field of view on standard and telephoto

 why was the great wall of china constructed

why was the great wall of china constructed

2. Why was the Great Wall of China bulit? The Great Wall of China was built to protect China from its enemies and invaders from the North, especially the Mongols. The Mongols were a tribal group that would regularly conduct raids into China. Despite the wall, the Mongols eventually conquered China. The Wall also kept Chinese citizens from leaving China. Actually, China is not the only country in history that built wall along its boundary. Athens, the Roman Empire, Denmark and Korea all did so at certain time in the past. The Hadrianйжжs Wall in northern England, built "to separate the Romans from the barbarians", extended 117 kilometres from Wallsend-on-Tyne in the east to Bowness-on-Solway in the west. All the walls were built for the purpose of military defense, and the Great Wall of

 why do my toes get numb when i exercise

why do my toes get numb when i exercise

Toe numbness during exercise is quite common, but that doesn't mean it's normal. It can be caused by something as simple as lacing your shoes too tight, or it could be a manifestation of a more serious condition that requires medical treatment. In most cases, toe numbness can be traced to improper equipment or technique, but if it continues after those things are fixed, it may be time to see a doctor. You should wear sport-specific shoes that fit properly from day one. It is important that your foot be cushioned and supported correctly for your specific sport, or you will end up compressing nerves in the ball of your foot or in your heel, which can lead to numbness or tingling in the toes. Don't lace your shoes as tight as they go -- as long as your heel doesn't slip out, they're tight

 why do shadows change length during the day

why do shadows change length during the day

Why does the sun move across the sky? The sun appears to move across the Earth's sky as a consequence of the Earth's rotation. As Earth turns on its axis, an observer on the surface sees the su. Why does the sun appear to travel across the sky during the day? The Sun appears to move across the sky during the day due to the rotation of Earth along its axis. Because Earth rotates from east to west, the Sun first a. ...

 why do we love sports so much

why do we love sports so much

The thing that drives you. The reason behind your ambition. The thing that catapults you (or in my case, not a morning person, slowly drags, but drags nevertheless) out of bed each morning. Your why. Whether or not we realize it, there is a why behind everything we do and there are ways in which to increase the motivational capacity of our "why's". My junior year of high school, in my English class, we examined how rhetorical strategies in literature, advertising, etc. all employ a motivating force. John Lennon once identified the two main motivating forces in a human's life as fear and love. When we are afraid of something, we draw back out of a desire to avoid the very thing with which we fear coming into contact. When we are motivated out of love or rather, passion or concern, we are

 why does windows 7 take so long to shut down

why does windows 7 take so long to shut down

Help! Computer takes too long to wake from sleep or shut down. having a problem in windows startup after a interrupted shut down due to low battery problem. Resuming windows takes much time i was installing a new copy of windows 7. It got hung up for a long time so I shut down the computer Now when I boot up the c windows 7 / 64 bit / is taking to long to shut down, and shuts down on its own randomly. ...

 why do plants in water need carbon dioxide

why do plants in water need carbon dioxide

Where Does a Plant's Mass Come From? Have you ever wondered where plants get their mass? All those leaves and branches have to come from somewhere, but where? It turns out that the main ingredients for plant growth are water, air, and energy. The air around you may seem empty, but it's not. Air is made of tiny bits that we call molecules. If you had enough air molecules, you could even weigh them. Two of the molecules in air are oxygen and carbon dioxide. You may think oxygen is the most important moleculeвwe need it to live. But carbon is important too. All living things on Earth are made of carbon. If you removed the water from our bodies, you would find that carbon makes up most of the rest of our weight, or mass. The same is true for plants. We get carbon from our food, but where do

 why does my car shake when i slow down

why does my car shake when i slow down

Sitting in a vibrating chair can be a very relaxing experience. But sitting in a vibrating car? Not so much. If your vehicle is vibrating or shaking, whether while idle or in motion, this indicates that something is wrong. Often times, the sensation will be felt through the steering wheel, but it can sometimes be felt throughout the entire vehicle. Left unchecked, this small problem could turn into a much bigger one. So why is your car vibrating and shaking? Here are some common causes: Wheels out of balance -- This is a that will cause vibrating and shaking in your automobile. Once your wheels get far out of balance, it can cause dangerous driving conditions, so it's important that you have them checked right away. Loose or disconnected hoses -- Several types of engine vibration are

 why do some cats not cover their poop

why do some cats not cover their poop

Covering poop is a normal behavior,бright? Not necessarily. Wild cats that bury their excrement do so for basically two reasons: One is to keep their presence unknown from possible predators. The other is to show that they are not challenging more dominant cats. These more dominant cats rarely bury feces, and often leave waste on grassy tussocks that elevate and make it even more prominent. So, it seems the only reason for a domesticated cat to bury her poop is if there is a dominant cat in the house. However, it is a very natural cat behavior. So why is your cat not doing it? Humans have encouraged the behavior in our pet cats, by selectively choosing (and breeding) the ones that are Бclean. Б Cats that leave their excrement uncovered for the world to admire are not abnormalБtheyБre just