1) prevent the light from reaching the leaf...cover it with a piece of black paper
2) controlled variables : amount of water, type of plant used
3) independent variable: presence of light
4) dependent variable: presence of starch
5)
6) using a table??
7) errr...not sure
because we have been doing this experiment for many years...and it is reliable...unless you screw up the exp...
9) follow the procedure CAREFULLY...

How to Improve your Digital Slr Camera Pictures?

Digital SLR cameras are amazing tools to expand your creativity and to document special moments. If your starting out and strive to improve your work master these five important tips. These tips deal with the relationship of shutter speed and focal length, achieving proper focus, stability, handling backlighting, and the effects of ISO and noise.

Understanding how the focal length of your lenses relates to the shutter speed you are shooting with.

If your shooting with a 50mm lenses the rule of thumb is that you can hand hold your camera with shutter speeds of 1/50th of a second and higher. With a 200mm lenses that it’s 1/200th of a second. With expensive image stabilization lenses you can hand hold a 200mmm at about 1/100th of a second maybe 1/60th of a second if you have steady hands. One trick I have used to squeeze an extra shutter speed stop while hand holding my camera is holding my breath and keeping my arm tight close to my chest. Knowing your lenses and remembering this simple tip should yield sharper results in your photos while hand holding your digital SLR camera.

Understanding the focus system in your camera

Practically every digital SLR camera focuses when you press the shutter button halfway down. Usually you will hear a beep and see a green or red square through the viewfinder. This is what the camera is focusing on. Then press the button the rest of the way down to take the picture. Understand that the computer inside the camera is looking at differences in image contrast and that difference is what is focusing the camera. Most digital SLR cameras also let you change the focus point manually to anywhere there is a predetermined point in the viewfinder. At a minimum you will get 9 points of focus up to 45 points of focus. It depends on the model and make of your digital SLR camera.

While executing my day-to-day shooting I always start with my focus point in the center of the viewfinder then I move it according to the subject I am shooting. It is easy to forget about where you set your focus point and then wonder why your photos are off focus or out of focus. So when you start a shoot the first place to check is where your focus point is and then center it, this should help you get more shots in focus.

Stability and when to use a tripod

If you are dealing with long exposures when shooting or if the shutter speed exceeds the focal length, then you need to use a tripod. All tripods are not the same. If in the studio a lightweight tripod can be used effectively if you weigh it down with sandbag or an alterative weighting device. When outdoors use a tripod on the heavier side is probably best, it also depending on weather condition. If there is a lot of wind you really need to secure the tripod with weight or some tripods even have a feature where you can spike them in the ground for more stability.

Any movement during a shot with a long exposure will almost always render that shot useless and that is why stability is so important. One of the newest advancements in camera technology is "image stabilization" in both lenses and camera bodies. This new technology is great and its best used if shooting with two hands on the camera and bracing your body against something. Still in some shooting situations there is still no replacement for a good weighted tripod.

How to handle strong backlighting

Backlighting subjects can be our enemy. Many people try to shoot a photo with a strong bright window light in the background, and then wonder why the shot didn't come out. Why does this happen? The bright light from the window floods the lens, and your camera usually can't compensate for it. One way to combat this is to use a fill flash on your subject or use a large white fill card. Another option is to diffuse the strong window light and fill the subject with a white fill card. Do not be afraid of backlighting use it to your advantage, just remember you need to counteract a strong backlight with a strong fill.

Understanding the effects of ISO in Digital SLR Cameras

Digital SLR cameras have some of the same characteristics as film SLR Cameras like interchangeable lenses, viewfinders, matrix metering, etc, but they do not handle ISO the same way. They are similar in that the relative ISO setting handles the light sensitivity that reaches the sensor or film. Where they differ is in the look they achieve in the final product. High ISO speeds on film have a certain film grain look to them that can be pleasing, but high ISO speeds on a digital SLR camera creates noise on the files and the look is not the same as film grain. In most situations noise is your enemy. If you want that film grain look, shoot your digital photos with the lowest possible ISO and then use Alien Skins Exposure® 2 plug in for Photoshop to achieve that film grain look.

In closing mastering these five tips will make your photography stronger, sharper, in focus and properly lit.

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