Each post in this series builds on information discussed in previous posts. See the Photography for Beginners page on the menu for links to all the posts.
In this post I’m going to discuss Shutter Priority Mode, usually designated by an S on your camera mode dial if it has one. (Tv, or time value, on Canon cameras.)
What is Shutter Priority Mode?
It’s called Shutter Priority Mode because you are making the shutter speed your priority in how you expose the image. In Shutter Priority Mode you control the shutter speed and allow the camera to automatically choose the correct aperture to go with it.
You have a decision to make about ISO. In addition to choosing the shutter speed you can also set the specific ISO you want to use. Or you can set ISO to automatic, and the camera will choose that setting for you along with the aperture.
If you set the ISO number and your combination of chosen shutter speed and ISO won’t work because the aperture can’t get large or small enough to compensate, the camera display will let you know by numbers turning red, or something similar.
It’s easiest for a beginner to use auto ISO because it’s one less detail to have to think about. But auto ISO isn’t just for newbies. A lot of professional photographers use it in many situations.
Whether auto ISO is a good idea or not can depend on your camera model. You should already know how your camera performs in terms of noise in relation to ISO settings. (See the Program Mode section in Part 2.)
With my previous camera it was more important for me to set ISO manually because I needed ISO to be 400 or under to get the sharpest photos. Though up to 1600 was okay in some situations when absolutely needed. My new camera handles noise much better so I will be using auto ISO a lot more often since I don’t need to worry about it as much.
When should you use Shutter Priority Mode?
Any time shutter speed is critical to the image you want to capture. This could be for practical purposes or artistic reasons.
Shutter Priority is especially useful in situations when you want to freeze action and avoid motion blur by using a faster shutter speed. It could be anything from your child playing soccer, to water flying from a fountain, to a bird in flight.
How fast your shutter speed needs to be to freeze action not only depends on how quickly your subject is moving, it also depends on how close you are, either physically or from zooming in/using a telephoto lens.
If you take a photo at the beach using a wide angle the waves will look fine with middling shutter speeds, despite the fact the waves are moving pretty quickly. But if you zoom in to get a closeup of a wave crest you will need a fast shutter speed to capture sharp details.
Creative Use of Motion Blur
There are times when you want to actually show motion blur in a photo for creative effect, in which case you need to slow the shutter down.
You see this in photos of waterfalls and automotive tail light streams at night. You’ll need a tripod for these types of very slow shutter speed photos (long exposures) in order to eliminate camera shake blurring. To get a slow enough shutter speed in daylight a dark lens filter is usually necessary.
Another type of motion blur used for creative effect is when much of the action is frozen and sharp, but the shutter speed isn’t quite fast enough to freeze everything.
Instances of this might be a karate tournament, a rock concert, or a moving car. With the correct shutter speed most of your subject will be fairly sharp, but there will be some blurring of the faster movement of the feet, hands, or tires, which conveys the energy and action of the moment to someone viewing the image.
Whether fast or slow, you will often need to experiment a bit to find the shutter speed that will produce the results you’re trying to obtain.
A starting point for using Shutter Priority is the Reciprocal Rule, which is actually just a very rough guideline, not a rule. The idea is to use your lens focal length to determine the minimum shutter speed needed for a decent photo. So if you’re using a 25mm wide-angle you could try as slow as 1/25. If you’re using a 200mm telephoto you’d need at least 1/200.
The Reciprocal Rule was developed in the film days, and even then it was only somewhat useful. For one thing, it assumes a stationary or slower moving subject, not something like a dog flying through an agility course.
With digital photography it breaks down even further. If your camera/lens has image stabilization you can use even slower speeds. But there are other things that mean you might need faster speeds.
You can use the Reciprocal Rule to give you an idea of where to start as a beginner, but don’t be surprised if you can go slower or need something much, much faster. In addition to your subject, how steady your hands are, how heavy your lens is, and other factors all play a role.
It takes practice.
Experiment! The only way to know what shutter speed you need for any given situation is from a combination of experience and trial and error in the moment. Even experts don’t always get it right the first time. They might need to take several shots before getting what they want. The more you practice, the more likely you are to get it right, or close to right, on the first try.
If your camera/lens does not have image stabilization (IS) shutter speed is a lot more important for all types of photos when you’re shooting hand-held. This is especially true if you have a zoom lens or are using a telephoto lens. The more you are zoomed in the higher a shutter speed you need to use to eliminate camera shake blurring.
If you are consistently disappointed because too many of your photos look soft or slightly out of focus, think shutter speed. It is possible something is wrong with the camera or you keep missing with your focus point, but it’s much more likely the problem is shutter speed.
Balancing ISO With Shutter Speed
When you have less light it can become a pitched battle between a fast enough shutter speed and ISO low enough to prevent noise degradation. It’s frustrating.
When shutter speed is critical it’s usually best to just accept more noise and boost ISO to make sure you get the shot. But once you have the shot you can try slower and slower shutter speeds. Sometimes everything works and one of those photos will turn out great, and then you have less noise.
When should you use Shutter Priority Mode?
Some photographers prefer Shutter Priority as their primary shooting mode because it suits their subjects, shooting style, or their mental process of how they think about capturing images. For most photographers Shutter Priority is a mode used when called for by a specific situation.
It’s a tool in your photographer’s tool box. It’s entirely up to you!
Photo #1 is an example of how shooting a wide scene from a distance often doesn’t require a fast shutter speed, even though the waves are constantly rolling and frothing.
Photo #2 is from a day I was playing around with shutter speed to see how fast it needed to be to capture water spraying out around a rock with no motion blur.
You might notice that even though the water is frozen in mid-air a lot of it isn’t sharply in focus. That’s mostly due to shallow depth of field, not lack of shutter speed. We’ll discuss DOF in the next post.
Photo #3 is from a day at the beach when I became curious how slow I could get my shutter speed in daylight for the water smoothing effect.
I used my smallest aperture and lowest ISO to allow the least amount of light, but the resulting 1/20 shutter speed still wasn’t slow enough to truly smooth the wave. It just ended up with a lot of non-artistic motion blur.
This demonstrates why a dark lens filter is needed to get a super slow shutter speed in daylight. I will also discuss filters in a future post.
Photo #4 shows what happens with motion blur in a long exposure. This was an oops. A couple walked in front of my camera (on a tripod) just as the timer opened the shutter for a 1 second exposure.
With the long exposure and the couple walking quickly the camera captures motion blur only, not the people themselves. Even though it was originally an oops I ended up liking the ghostly effect and tagged this as a keeper.
This is a trick that a lot of travel photographers use to either reduce the impact of people in a photo or, with a long enough exposure, remove them entirely. It comes in handy if you want a good photo of a monument but don’t want throngs of sightseers cluttering things up. Blurred crowds are much less distracting. A tripod (or conveniently placed rock or low wall) is necessary, and if done in daylight a dark lens filter is again needed in order to make exposures ranging from a couple seconds to several minutes.