What is Aperture Priority? Have you ever looked at the mode dial on the top of your D-SLR and wondered what the other settings are outside of auto? Within this series of introductions I hope to help you on a voyage of discovery.
What is Aperture Priority?
Quite simply put, within this mode, the aperture that the camera is adjusted to is the primary setting, the camera will then calculate the shutter speed and ISO.
I’m still unsure – what is Aperture Priority!
Fair enough – took me a while to get my head around the settings and how they work!
The aperture of the camera can be likened to the pupil of the eye. Ever noticed that in very shadowy, dark environments, the pupils of the eye dilate, growing bigger, but in very bright conditions they contract into a very small dot in the middle of the iris?
This is due to the amount of light that is being passed through the eye to the brain, making sense of the world around us. The body needs to stay safe, therefore if the ambient light is very poor, the pupils dilate to allow as much light in as possible to ensure you don’t trip over any unseen hazard.
Aperture numbers also work backward, the larger the number, the smaller the aperture. Typically, aperture values range from F2.8 (large opening) through to F22 (very narrow).
Ok, I get that, but how does this explain what is Aperture Priority?
The camera needs to see in the same way as the human eye, to make sense of the world around, the sensor of the camera needs a specific amount of light to capture the image.
However, Aperture Priority (AP) allows you to set the aperture to meet the various conditions that you encounter in your travels, allowing you to create your unique image in your style.
In AP, the camera will then determine the shutter speed and ISO value to create the image. You should be aware that this may result in a very slow shutter speed being achieved. It is recommended that for any shutter speed below 1/60th that the camera is mounted on a tripod to avoid camera shake and disappointment.
Aperture is also very important in creating stunning images due to the Depth of Field. Like the pupil of the eye, the larger the aperture (F1.4), things in the distance are going to be out of focus, blurred, but the foreground to be pin sharp. Great for close up portrait shots.
As you can see in the portrait snap of our cat, Alfie, his face is in focus, the eye on the left being the point of focus, his body and the background are out of focus. This was taken using a Sigma lens with an aperture value of F1.4, matching Alfie’s pupils!
Working with a very small aperture (F22) the foreground will remain in focus as well as any objects in the distance. Great for landscape photos.
It is also worth noting that dependent on your camera’s capabilities, in AP mode, a high ISO value may result in a very grainy, noisy photo. Whilst this may be appropriate for some photos, a portrait of a new born baby which is grainy probably wouldn’t be the right subject.
A lot of photographers recommend AP as their preferred method of taking photos, which I think is a great way of easing yourself away from auto, a gentle transition toward manual mode.
It is also the suggested setting for using the Lensbaby Optic Swap System taking some of the pressure off learning to create beautiful, diverse images. The Lensbaby system uses magnetic aperture discs which are simply dropped in front of the optic.
Due to the aperture discs, the automatic setting in the camera will not work, therefore you have to tell the camera what aperture you are working with, it then calculates every other setting as previously described
Some people (and everyone has their own opinion) would argue the point why bother? Surely the Manufacturer’s Auto setting is more than up to the job?
Whilst they try their best to achieve great results in the auto mode, you will find as you become more confident within your photography that this has limitations, the image it captures doesn’t reflect what you saw. This is where AP (and other modes) come into their own, allowing you to express your creativity.
In the day of 35mm SLR film cameras, the photographer crafted their photo, taking a light reading, ensuring the correct exposure for the shutter speed. Using the dial on the top of the camera, you set the ISO to the value on the film canister and you created an image.
This is what I am hoping that you will do by taking your first step away from auto and discovering what is Aperture Priority.