As a professional photographer, I’m often asked by friends and clients how to use their cameras. Last month we began learning how to get more out of our DSLR cameras by looking at automatic modes. Today, we will go a step further and look at the semi-automatic camera modes.
What are Semi-automatic Camera Modes?
Semi-automatic camera modes give you, the photographer, a little more control over how your pictures will look. The camera will still be calculating what it thinks the proper exposure will be.
Most cameras have three camera modes that can be considered “semi-automatic:” Program mode (P), Shutter Priority mode (Tv or S), and Aperture Priority mode (Av or A).
Program mode (P)
Program mode is designated by the letter P on your camera’s dial. It operates a lot like Automatic, except that you can control the flash, the ISO (that’s how sensitive your camera is to light), and the white balance.
What are those things and why would you want to control them?!
Let’s start with the flash. Sometimes you may prefer the look of a setting as it is naturally lit. An image can have more impact when parts of it are in shadow. The natural balance of light and shadow gives ambiance.
The ISO is another aspect that you can control in P mode. As I mentioned before, ISO determines how sensitive your camera is to light. But what does that mean? If you are in a very bright, outdoor setting, you can set your ISO to a lower number. And if you are in a very dim, indoor or outdoor setting you can set your ISO to be higher. This would give you the ability to capture motion blur or light trails with sparklers or at sunset.
One thing to keep in mind is that the higher your ISO, the more noise or grain you will have in your photo. Here’s an example of a photo taken in a very low light situation. I set the ISO to 3200 because I wanted just the candle light to light the image.
If I zoom in on the upper right corner, you can see the noise more:
I honestly don’t mind the noise in this image. I think it actually adds to the overall look. However if you are photographing people, noise and grain can be more distracting.
The other thing that you can control in Program mode is white balance. White balance is the temperature of the photo. The photo on the left side is the auto white balance the camera chose. I changed the white balance to “shade” for the photo on the right. You may need to look in your camera’s manual to see how to adjust your white balance.
Aperture Priority Mode (Av or A)
When you set your camera to Aperture Priority, you can control something called Depth of Field (DoF). Have you ever looked at a portrait and noticed how the background or foreground is blurred and the subject is in focus? You can achieve that look with a lower aperture or f/stop. Here’s an example:
In this image, I set the aperture at f/2.8. The children are in focus, and the grasses that are behind them are more out of focus the further away they are.
With Aperture Priority mode, you can lower the aperture to a lower number to achieve these types of looks. The camera will then determine what shutter speed to use to expose your image for the light it has metered. You are in control of setting the ISO so you can control the amount of noise in your image.
You can increase the aperture so that more of your image is in focus which is good for larger groups or landscape images.
For instance, I set the aperture to f/16 in this image:
One thing to remember when you are using Aperture Priority mode is that your camera is picking the shutter speed. If the shutter speed is long (less than 1/60), your image may not be in sharp focus because of possible hand-shake or the subject may move a bit. You may need to use a tripod to prevent hand-shake issues.
A great time to use Aperture Priority mode is when the light is changing quickly and you want to maintain a consistent exposure. The following images were taken as the sun was setting in the Grand Canyon. I set my aperture to f/9 and adjusted the ISO, and then let the camera make adjustments to the shutter speed so that I could spend more time enjoying the beautiful views and less time looking at my camera settings:
Shutter Priority Mode (Tv or S)
Shutter Priority mode allows you to set the shutter speed. You are also in control of the ISO. The camera adjusts the aperture based on the lighting in your image. If your shutter speed is high and the aperture can not go low enough, the ISO value flashes to alert you to adjust it for what the camera determines as proper exposure.
Shutter priority is great when you are photographing sports or wildlife or active children. A faster shutter speed lets you freeze quickly moving objects. For instance, I don’t let my shutter speed fall below 1/250 when I am photographing children. And I keep my shutter speed above 1/500 when I photograph sporting events.
In the example above, you can see that the girls closest to the ball are in crisp focus even though they are in motion. The girls who are further from the ball are slightly out of focus due to a more shallow depth of field.
Shutter Priority mode can also help you get images with motion blur by setting a longer shutter speed.
Many DSLR cameras offer an automatic ISO setting. As you are learning how to use these semi-automatic modes you may want to try using auto ISO so that your camera can react quickly as lighting changes. After all, while it is great to take control of your pictures, you don’t want to miss great images while you are learning!
I found that using the semi-automatic modes really helped me to begin understanding how to get the kinds of pictures I wanted from my camera. But the only way to really learn is through practice!
- Pick up your camera every day for the next few weeks and spend 10-15 minutes taking pictures.
- Spend time using each of the different semi-automatic modes each practice session.
- Take photos of the same subject using different apertures or shutter speeds
- Practice taking pictures at different times of day and in different lighting.
- Look at your photos on your computer (the back of the camera is deceptive and won’t give you a true idea of how your photo turned out) or get them printed and see how the adjustments you make affect the way an image looks.
Next lesson we will begin looking at the exposure triangle to better understand exposure. Once you begin to understand exposure you can have even more control over how your images turn out!