Depth of field preview
This is a button on the camera body that allows me to stop the lens down to the aperture I am using. The image in the viewfinder will become dark and it will show my how much of the picture is going to be in focus. My lens gives me the point of focus and the aperture gives me the amount that will be in focus. It is usually 1/3 in front and 2/3 behind the point of focus.
Mirror Lock up
Not all camera manufacturers offer the feature of mirror lock up. It is a very important factor that I overlooked when I bought my latest equipment. I would have preferred this function, as it will lessen the amount of camera shake when you make a picture. At certain shutter speed the vibration from the mirror is more noticeable. I have to try my best to not use shutter speed in the 8 to 15 second ranges or I may not be pleased with the sharpness of my pictures, even though I use a tripod 99% of the time. With mirror lock up you would compose you picture and just before making the picture you would switch the mirror lock up button to swing the mirror out of the way. It makes for one less piece of you equipment moving during the taking of the picture.
Other features
Why buy a camera that offers more than just an auto exposure mode. Most of the mid to high end cameras offer you the option to shoot: Keep in mind that the meter in the camera is only going to see things as a middle tone or 18% gray. I will explain this further.
Fully automatic
Aperture priority
Shutter priority
Fully manual
Choosing your Camera
I will take you thru my experiences in buying photographic equipment. I purchased my first camera over 20 years ago. If I had the knowledge I do now I may have made a few different choices. What I now look for in buying a camera are what most professional photographers consider the most important features.
(where the camera pick the aperture and shutter for you)
This setting is great if all you are shooting is a subject that is a middle tone, but if you are shooting a white flower or a dark brown moose you picture will come back looking more or less a middle tone.
(where you control the aperture and the camera controls the shutter)
This setting can be used if you want to be more in control of how much of the picture is in focus (depth of field)
(where you control the shutter and the camera controls the aperture)
Use this mode when you want to be in control of the speed at which your shutter is set. Faster shutters will stop the action and slower shutters will blur the subject. If you were shooting a bird you would need a fast shutter (250, 500,1000) to stop the movement of the wings. And to give the affect of water moving you would use a slow shutter speed (1/8, 1/4, 1/2 or slower) to blur it’s movement.
(where you control both the aperture and shutter)
If you were serious about becoming a photographer I would recommend you learn how to use this mode. It gives you the most control and with a lot of practice it will give you the best pictures. In the mode you need to control both the shutter and the aperture. Most cameras will tell you how close to the meters reading you are with you settings. All you need to do is decide if the subject you want were have as correct exposure is lighter or darker than middle tone. Looking back at the white flower, it is lighter than middle tone so you need to increase you exposure to keep the whites white. The dark brown moose needs to have the exposure decreased in order to keep it dark brown. The amount you increase or decrease will depend upon your subject and the amount it takes up in your viewfinder. This is where you need to get out and take those pictures and experiment with you new camera.