What Exposure Mode Should a Photographer Use?

By Lane Erickson

“In the right light, at the right time, everything is extraordinary.” – Aaron Rose

Sometimes people ask me how I use my cameras to create the images I’ve made. A frequent question I’m asked is “What exposure mode should a photographer use?” It’s a good question, but really I think it is the wrong question.

You see, to me, as fun as cameras are to look at and hold and talk about . . . in the end, a camera is only a tool. As a tool, it should be used by each photographer in the way that best helps them create great images. For each photographer, this could be different. 

Having now preached the truth, I will rephrase the question to be: “What camera exposure mode should a photographer use for this situation?” 

Exposure for a Photograph

I’ll assume for a moment, you don’t know anything about photography so we can talk about the basics of an exposure. Most modern cameras have several “exposure modes” that you can choose to use when you take a photograph. The exposure mode is the way your camera determines how much light will strike the digital sensor so a picture can be captured by the camera. 

To keep things simple, exposure is controlled by 3 things: 

  • How sensitive to light the digital sensor is (called the ISO (in the old days we called this the film speed)); 
  • How long the shutter is open to allow light to strike the digital sensor (called the shutter speed); and 
  • How big a hole in the lens the light travels through to get to the sensor (called the aperture). 

Except for the manual mode, the different exposure modes on your camera create a “correct” exposure by making adjustments to the 3 things listed above, depending on the choices you make as the photographer. For example, if you choose the shutter priority mode, you are choosing the shutter speed at which the picture will be taken. The camera will then adjust either the ISO or the aperture or both so that with the shutter speed you chose, enough light strikes the digital sensor to create a photograph. 

In the manual mode, you control all 3 of the things listed above: ISO, shutter speed, and aperture, manually. In other words, you manually decide the exposure. The camera makes no adjustments at all. 

In my photography I find that I use 3 different exposure modes, depending on the situation I am photographing. These modes are: Aperture Priority (I use this about 85% of the time), Manual (used about 10% of the time), and Shutter Priority (used 5% or less of the time). 

Let’s explore each of these exposure modes and use some photographs to illustrate how they work. 

1. Aperture Priority

In aperture priority mode, you choose the aperture (how big a hole in the lens the light comes through) and the camera automatically chooses the shutter speed, and the ISO if you have that setting placed on auto, to allow enough light to strike the digital sensor so an image is created.  I use this setting about 85% of the time. There are 2 good reasons why I do this. 

The first reason is that by using aperture priority mode, I am controlling not only the exposure, I am also controlling focus. The aperture of a lens affects how wide or how narrow the focus will be in the image. The larger the number, such as f/16 or f/22, the more that is in focus. The smaller the number, such as f/2.8 or f/2, the less that is in focus. 

The second reason I use aperture priority mode most of the time is that it is fast.  I can capture fast moving action with this setting without much anxiety. These 2 images were created with the aperture priority setting so I could control the area of focus in the image.

Winter pine trees frozen forest in the snow
Girls with Corsage Flowers for Prom.

Keep in mind that no mode is perfect, including aperture priority mode. Many times I need to adjust the exposure through the compensation dial (+1 or -2 for example) to get the exposure the way I want it. 

2. Manual

My favorite camera of all time is the Nikon FM2N.  It’s an all manual camera. You have to set the ISO . . . and the shutter speed . . . and the aperture . .  all manually. Nothing is automatic on this camera. 

I learned more about photography by using my Nikon FM2N than in any other way because I was forced to set everything manually. This is also why I love the Fujifilm X system of cameras. They look and feel like a manual camera, and can be used as a manual camera, but can also be used on several auto exposure modes.


If you always use the auto settings on your camera, you will never know what the settings mean or how they affect the image. Because of this, I recommend the manual setting for all photographers, especially while they are learning photography. 

In manual mode, a person can instantly see what happens when they change the shutter speed, or the aperture, or the ISO setting. This is how a person comes to know what settings to use when they want to create a certain look in a photo.  I used the manual setting to capture this composite image of the solar eclipse.

Solar Eclipse of Sun by Moon in North America 2017.

I also used the full manual setting to take images that I stitched together for this panorama image of a windmill. This allowed me to keep the exposure consistent so the stitched photo looks natural.

Windmill on hillside in countryside rural America with sky and clouds

3. Shutter Priority 

Shutter priority mode is where the photographer chooses a shutter speed and the camera chooses the ISO and/or the aperture so enough light strikes the digital sensor to create an image. 

Detail of Camera Shutter Speed Dial and ISO.

When you use shutter priority you lose the ability to control the amount of focus the image will have. But, you control the shutter speed. This allows the photographer to create sometimes unusual and creative images. I used shutter priority to create this image of runners because I wanted a slow shutter speed to show motion.

Runner running a race around a track holding relay baton.

I generally only use shutter priority when I am shooting action and I either want to freeze the action completely or I want to show some motion in the photograph.  I used shutter priority to provide just the right amount of motion to the windmill turbines.

Power generated by wind with windmill turbines spinning.

Conclusion

So what exposure mode should you use on your camera? The best advice I can give any photographer is to learn how your camera works.  Once you’ve done that, you can choose the right tool or exposure mode that will help you capture the image you want to create.  

If you still don’t know which exposure mode to use, then go manual. By using the manual setting, you will learn more about the craft of photography and your images will only get better.  

Always open to comments, I welcome your thoughts, suggestions and even your critiques. 

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2 Comments

    1. Marc, thank you for your comment. You are absolutely correct. Depth of field is also known as the “area of acceptable focus”. My goal was to keep the article simple, and try to keep the technical jargon to a minimum.

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