You are looking at two pictures, one is very bright with pale colors and has a harsh appearance. The other photo is dark, so dark you can barely make out the subject. What do both of these photos have in common? You got it...the wrong exposure.
Exposed!
Exposure is the amount of light your camera's sensor picks up. To put it simply, it's how bright or dark a photo is. Aperture, shutter speed, and ISO are the go to guys to create the right exposure for your photo. You will find however, that the camera relies more heavily on aperture and shutter speed to control exposure when the ISO is constant (in a setting where you do not need to change the ISO).
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| Effect on exposure by changing shutter speed Photo courtesy of Wikipedia |
Bring on the diagram!
The diagram below shows the relationship between the three amigos: aperture, shutter speed, and ISO as if you haven't heard enough about them already! Am I right? I feel your pain, but they are really very important to your success as a photographer. Once you've got this all figured out, it's all downhill from here! The chart is rather helpful in giving you a visual reminder as to the effect of each function.
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Aperture: The opening within the camera's lens that allows varied amounts of light to reach the sensor.
Shutter speed: The length of time the camera's shutter is open.
ISO: Measures the camera's sensitivity to light.
Which shooting mode is best to use?
Today's digital cameras are equipped with different shooting modes that are of great help to the amateur photographer. I thought it would be useful to discuss the different modes and how they either help or hinder your efforts to properly expose your photo. The semi-automatic modes Aperture Priority (A or Av), Shutter Priority (S or Tv) and Program mode (P) will give you some creative control of the shot.
Aperture priority allows you to set the aperture while the camera controls the shutter speed and exposure. It's important to keep in mind that the camera doesn't always get the exposure right in this mode, you may have to use the exposure compensation feature to lighten or darken the photo.
Shutter priority does the reverse of this. You control the shutter speed to either blur or freeze the action you want to capture and the camera selects the aperture and exposure. In this mode again, you may need to use exposure compensation to achieve a more balanced exposure.
Program mode allows the camera to make the decisions as to aperture, shutter speed and exposure. This leaves you free to focus on how to set up your shots. Some cameras allow you to override the settings the camera uses in this mode, but the Nikon D40x does not offer this feature. This is not a major concern because it does a really good job selecting the settings that will produce a great shot.
Tip: If you are shooting in a situation that requires you to switch between the aperture priority and shutter priority modes, you may want to give the manual mode a try.
Manual mode (M) is the mode preferred by professional photographers because it gives them full creative control of the shot. In this mode, they select the aperture and shutter speed to obtain the correct exposure. For an amateur photographer, using manual mode can seem a bit daunting at first. My suggestion is give all of the shooting modes a try to become familiar with them. This was a useful tip for me because it enabled me to take the plunge from automatic mode into semi-automatic mode and now I use manual mode quite frequently. Give it a try! You will love it!
So when deciding which shooting mode is best for you, select the mode that will give you control of which effect you want primarily in the shot. If you want your photo to convey movement, choose shutter priority and if you're seeking the dreamy blurry background (great for portrait shots) then choose aperture priority. Easy peasy mac and cheesy! Like my kids always say.
Tip: After making your selections for your photo, if you find that your photo is over exposed or underexposed, use exposure compensation to darken or lighten it. When adjusting exposure compensation, the Nikon D40x makes it easy for you because it displays on the monitor how a picture will look like at different exposure settings. This is very helpful to use until you get the hang of selecting the correct exposure for the scene you are shooting.
Take me with you!
The following exposure value chart is great to print and take with you.
Exposure Value: Each of the following shutter and aperture combinations allow a balanced amount of light to enter the camera lens. Decide which effect you are looking for, a fast shutter speed to freeze motion or a small aperture to bring everything you are shooting into focus. Make your selection and then adjust the other function using the chart below.
Shutter Speed Aperture
(Slow to fast) (Small to large opening)
1/4 f/22
1/8 f/16
1/15 f/11
1/30 f/8
1/60 f/5.6
1/125 f/4
1/250 f/2.8
1/500 f/2
1/1000 f/1.4
