Shutter, Aperture, Manual, Oh, My!

At our last meeting, we had quite a discussion about the best method to capture wildlife in photography. I suspect at least a few people went home more confused than anything. This is a difficult topic as there is more than one way to capture an image. 

I have my biases on the topic, but I have developed those through learning and understanding how the various functions on my camera work. I think that for those who were lost, understanding the basics will begin to get you back on track and allow you to try out different ways to capture an image. 

I will also say that the best way to learn, when you have at least a basic understanding of all the moving parts, is to go out and shoot, shoot, shoot. Back in the days of film photography, it was said that film was cheap. This was a signal that trying many things to make sure you got the image you really wanted was smart. You did not see your results until after the film was processed and images were printed. Today, you can see what you have right away and digital space is cheap so, shoot, shoot shoot, but in between each shot, modify something so that you can see what works and what doesn't.

Definitions:

ISO/ for the old school it was the ASA: ASA was the speed of the film, today it is called ISO and it is the speed of the sensor in you camera. With film a low speed like 64 or 100 was the sharpest, least grainy of the films. The films that I used went up to ISO 1000 and over the years of films development, improvements were made to make the film at higher speeds less grainy. Many people used the high speed film to get the grain for a different artistic point of view. Today, the high ISO's can show what is called noise which looks a lot like grain. Newer cameras are getting better and better sensors which is reducing the amount of noise we see in am image at higher ISOs. 

Shutter speed: how long your shutter stays open bringing in light to expose the film. Really fast is 1/2000th, 1/1500th, or 1/1000th of a second. Slow for hand held photography is 1/60th, 1/125th of a second, and really slow can be 5, 10, 20, 30 seconds or bulb (which is actually determined by how long you press the shutter and hold it before releasing it). (You need a tripod and a remote trigger for these long exposures to work. (The lens you have will also play a part in how fast your shutter speed needs to be to keep from seeing shake (blur)). With the bog lenses like a 300 mm lens, you need to have a faster shutter speed or a tripod because the lens will move slightly in your hand.

Aperture aka the f-stop: how big that hole letting light onto your sensor is. Not all lenses are created equal and often the smallest f-stop is 3.5  or 5. The smaller the number the bigger the hole of light. This means as it gets darker, and you need more light, you can go to a smaller f-stop and increase that light. At least until you are at your smallest number. Once you hit that, you will have to change some other setting to allow more light to hit you sensor. 

Color balance: How your camera reads the light; warm 5000K or Cool 3900K. Day night, Sunlight or artificial light.

How much and what control you take of your camera happens when you select the following:

Manual (M): You are taking control of the aperture settings and the shutter speed. 

Aperture priority (Nikon it is A, and Canon it is AV): You are taking control of the aperture and letting the camera choose the shutter speed to get enough light to make sure the aperture is constant.
Shutter priority (Nikon it is S and Canon it is TV): You are taking control of the shutter speed and letting the camera choose the correct aperture to get enough light to keep the shutter speed constant.
Auto (Auto): The camera choose both the shutter speed and the aperture. I have noticed that with my camera, it generally chooses a high shutter speed and will reduce the aperture to get enough light to expose the image properly. This is not necessarily good for landscape photography. Auto also decides you ISO, and white balance goes to auto. (I almost never use this setting unless, I am taking photos for work and am in a really big hurry. 

Program (P): These are setting available on most cameras that the manufacturer has created to allow you to be in Auto, but to tell the camera what kind of auto you mean. You can set your camera to the little running person when you want to capture things that are in motion. The main thing is that you have limited control over settings on your camera. If you like letting the camera take control instead of you taking control, you may want to consider this. As John Dickinson said at our last meeting, when you can shoot in Manual (M), then you have a complete understanding of what your camera is doing and you will understand what is happening in Auto or Program mode.

Note: Auto and manual focus is a separate feature that works independently of  Manual, Aperture, and Shutter priority settings. The ISO is also controlled separately.

The bottom line is that shutter speed, aperture, ISO, and your lens all play a role in getting enough light to your sensor to give you the image that you want. It comes down to what is most important to get right in your image. If you want to take a landscape photograph and have the photograph in focus from the closest point of the image to the camera, to the farthest point, you need to make sure that your f-stop (aperture) is set high enough to make that happen. This is called depth of field; often referred to as DOF. The bigger that number is the more you will see in focus from closest to farthest. However, if you are trying to stop a speeding train or flying eagle, you need to make sure that your shutter speed is set properly to allow you to stop the action. 

Here are some links to other articles written by people in the field of photography:

Digital Photography School on Aperture vs. Shutter Priority.

Image Maven on Aperture, Shutter, and Manual Priority.

Digital Photo Secrets on Aperture, Shutter, and Manual Priority.

More from Digital Photo Secrets and why we might think Aperture Priority is more important than Shutter Priority; well, maybe depending upon what you are shooting.

I did a little experiment when we were out shooting the eagles at Lock and Dam 14. I shot some in Shutter Priority and some in Aperture Priority. It was recommended to me by two people that I st the Aperture to f5.6 as my DOF would be fine to capture an eagle from head to toe with this setting. My ISO was 500, and the shutter was 1/1500th of a second. I lowered the ISO because at f5.6 it was often shooting at 1/3000th of a second and I knew that I did not need that much speed to capture a soaring Eagle. The Shutter Priority images were set at ISO 800, shutter speed 1/2000th of a second.

This was taken in shutter priority: 1/2000th of a second, f6.7, ISO 800. No crop.

This was taken in aperture priority: 1/1500th second, 5.6, ISO 500 It was slightly cropped. 

I hope that even if you were confused at the last meeting that you will come back again. Each meeting is a new learning opportunity and after a while the discussion begins to make sense. You may even want to jump in with your own thoughts.

I also hope that this post helps to clarify a few things for you so that you can make some decisions about how you use your camera.