I used the 350D to get these shots.
Regarding Av mode and Tv mode, its all really simple.
Let me explain
When you take a picture with your digital camera. What happens?
Light falls on your sensor through your lens and your sensor records it.
So if very less light is captured, you get a dark image, if more light is captured you get a bright image.
Your camera offers you various tools on controlling "exposure", i.e. the amount of light
1. Aperture : this is the lens opening. The wider you open the opening, the more amount of light will come in. For example if your room window is fully open, it will be brighter, right?
2. Shutter speed : The more time your shutter is open, the more light will fall on your sensor, and more "number of photons" will be captured by your sensor. But if you open the shutter too long, you will get "motion blur" if the subject is moving, or hand shake blur, if your shutter speed is slower than 1/<focal length>. Suppose you have a 300mm lens, a rough rule for people whose hands are somewhat stable is -> use a 1/300 shutter speed atleast. Some people can shoot steady with 1/100 speed too(for example surgeons, who have steady hands). There are people who can't take a steady shot with 1/600 speed also on a 300mm lens. Example is software engineers after 100 cups of coffee a day.
3. ISO : This is the sensor gain. Its the volume button. what happens when you increase volume on your stereo? Well you get more sound, but at the same time distortion also increases, right? Its a poor analogy, but think of this in same way. If you increase ISO noise will increase. Canon 350D is really good in the sense that even at ISO 1600 noise levels are acceptable. Hooray for canon CMOS
So if you are at a place where its very dark and you are unable to take steady pics do this
1. If the subject is stationary and nearby, use flash. Max flash speed is 1/200, but you can go slower if you want. There is a C.Fn to do that, look up the manual
2. If the subject is far, flash is useless, use a tripod
3. If the subject is moving, you need a fast shutter speed, tripod is useless.
So in case 3, first select the focal length at which your subject looks okay. Lets say you are shooting a bird far away. Using your 18mm Focal length will show the bird as a dot, not something you want, so zoom in.
Then select the widest aperture, lets say F5.6(which was in my case) I used a 75-300Lens.
Select ISO 400 and half press, and see the shutter speed you are getting. So if you are getting 1/200 and your focal length is 1/300, you can get camera shake, so up the ISO to 400.
You may be a surgeon and may get better shots at slower shutter speeds, or you may be a coffee addict, in which case you may need to go to ISO1600.
Hope this post clears up the confusion! |