The camera selects both the shutter speed and aperture. You choose ISO and white balance. This is a semiautomatic but shiftable mode. When you press your Shutter button halfway, the camera shows you its ideal exposure setting in the viewfinder. You have to remember that this is held for only one shot as it goes right back to the suggested exposure. Another thing is that you cannot shift the exposure if you are using the built-in flash. Use this mode when you want to quickly change the depth of field and shutter speed for one shot while experiencing minimum camera adjustments.
Tv mode (Shutter Priority)
In addition to ISO and WB you select shutter speed and the camera chooses the appropriate aperture. This mode is used when you want to control how motion comes across. A slower shutter speed will show motion as a blur. A faster shutter speed will freeze motion. This mode is also helpful when you want to make sure that the shutter speed is within the limits for handholding the camera and getting a sharp image.
Tips that I want to remember: (credit to Charlotte K. Lowrie’s book “Canon EOS Rebel T1i/500D)
- Use 1/250 second when action is coming toward the camera.
- Use 1/500 to 1/2000 second when action is moving side to side or up and down.
- Use 1/30 to 1/8 second when panning with the subject motion. Panning with the camera on a tripod is a really good idea.
- Use 1 second and slower shutter speeds at dusk and at night to show a waterfall as a silky blur, to caputer light trails of moving vehicles, to capture a city skyline, and so on.
Av Mode (Aperture Priority)
You set ISO and WB as well as aperture (f-stop). The camera chooses the shutter speed. You use this mode when you need to control the depth of field (DOF). A larger aperture (smaller number) will give you a shallow DOF and is good for isolating points of interest like flowers/portraits. A wide aperture like f/5.6 will create a shallow depth of filed with a softly blurred background. A smaller aperture (higher number) gives a greater DOF and is good for landscape photography. A narrow aperture such as f/8, f/11, f/16, and so on, gives an extensive depth of field that will keep both foreground and background in focus and sharper.
Tips I want to remember for Av: (credit to Charlotte K. Lowrie’s book “Canon EOS Rebel T1i/500D)
- Since the only lense I have at this point is the Canon EF-S 18-55mm f/3.5-5.6 IS lens) , this tip is specific to it. When you have the lens set to 55mm, the widest aperture you can choose is f/5.6, and you can’t choose f/3.5 at this zoom setting. This is called a variable-aperture lens.
M mode (Manual)
This mode allows the most creative control. First you determine the ISO and WB settings. Then, based on a meter reading, you set aperture and shutter speed in order to get the scene as you desire. You have to think about how motion and DOF will come across.