Photography: Aperture & Shutter Speed - Part 2

When trying to control the amount of light that comes into your camera there are three things you can adjust; Aperture, Shutter Speed, and the ISO.

Repeat:  This is an important point I need to make that I did not mention in the previous blog. This entire blog series assumes that you are using your camera in Manual (M) mode. A lot of what I am about to say is valid in all the different modes your camera offers you, but you do not have total control unless you are in Manual (M) mode. If you really want to learn about photography, you must shoot in Manual (M) mode. Once you fully understand what we are about to talk about in the next few blogs, then you can revert to the auto settings if it suits your needs at the time? I don't need more the two hands to count the number of times I have shot in anything other than Manual over the past 25 years.

Shutter Speed

Again, in a previous blog we talked about how adjusting the shutter speed will affect how much light comes into the camera, and contributes to properly exposing the image. Shutter speed works hand-in-hand with the aperture to properly expose an image. If you increase the shutter speed, such as going from 1/125 to 1/250 second, you will decrease the amount of light that comes into the camera. If you decrease the shutter speed, such as going from 1/125 to 1/60 second you will increase the amount of light that comes into the camera. If you are shooting slower than 1/60 second, I strongly recommend you use a tripod or something else to help keep the camera perfectly still.

Well, like the aperture, the choice of shutter speed has a creative affect on the look and feel of the image as well. For example; if you are photographing a baseball game. There are times when the players are still and a fast shutter speed is not necessary. But if you are shooting at a slow shutter speed, such as 1/60 of a second, and the players are in motion, such as running to first base or swinging at a pitch, the image will be blurry. The reason being that from the time you hit the shutter release and the time the shutter opens and closes, the baseball bat will have moved. But if you take that same image at a high shutter speed, such as 1/500 second, the shutter opens and closes so fast that in that time period the bat will not have moved. In essence, you will have been able to freeze the bat.

If you take a look at the images below, they are a couple of examples of using a fast shutter speed when you are photographing an action scene. I shot these at 1/500 second, but I really should have been using 1/1000 second. I know this because the ball is not completely frozen, there is a little bit of a blur. But overall, it did the trick.

Now, there are times when a slow shutter speed will give you the desired effect you are looking for. For example, an image that you have probably seen many times, a small misty waterfall in a creek where the water going over the falls looks like a stream of smoke. In order to capture this effect, you have to be shooting at 1/15 or 1/8, or even slower, depending on how big of an effect you are trying to create.

You can see in the two images below the difference between shooting the same scene at a high shutter speed and shooing it using a slow shutter speed. There is a dramatic difference. Some images don’t look as good frozen in time.

The last image I did not have a tripod and I was in a very precarious position, so I had to braise up against some rocks.

So as you can see, the choice of shutter speed not only contributes to the exposure of am image, but also can contribute to the creativity of the image.

Tip:  If you are trying to get the misty effect with a waterfall and that waterfall is in the sun, you are probably not going to be able to. The reason is that even if you choose the smallest lens opening such as f22, because it is so bright outside, you are probably not going to be able to select a slow enough shutter speed to get the effect. This always works better when the waterfall is in the shade.


Putting It All Together

So we know that there are many combinations of aperture and shutter speed that will give you a proper exposure. And as you increase the shutter speed you have to open of the lens using a smaller aperture. And conversely, if you are shooting at a slower shutter speed you will have to close the lens opening but choosing a higher aperture. But from a creative point of view, what are you trying to accomplish? Are you shooting a action scene where a fast shutter speed such as 1/500 second is more important than a lot of depth of field? Or are you shooting a landscape where you want everything in focus, so a bigger aperture such as f16 is more important than a fast shutter speed? Or are you photographing a person and you want everything other than the subject to be out of focus, so you want a small depth of field and therefore you are going to use a smaller aperture such as f4 and a matching faster shutter speed. This is where going out and just shooting and trying different settings for the same subject will teach you a lot.

Now that you know how shutter speed and aperture work together to create a properly exposed image and capture the look and feel you are after, GO OUT THERE AND SHOOT!

Photography: Aperture & Shutter Speed - Part 1

When trying to control the amount of light that comes into your camera there are three things you can adjust; Aperture, Shutter Speed, and the ISO.

Note:  This is an important point I need to make that I did not mention in the previous blog. This entire blog series assumes that you are using your camera in Manual (M) mode. A lot of what I am about to say is valid in all the different modes your camera offers you, but you do not have total control unless you are in Manual (M) mode. If you really want to learn about photography, you must shoot in Manual (M) mode. Once you fully understand what we are about to talk about in the next few blogs, then you can revert to the auto settings if it suits your needs at the time? I don't need more the two hands to count the number of times I have shot in anything other than Manual over the past 25 years.

Adjusting the ISO does not have any direct creative aspects. Simply put, you can adjust the ISO so that if the quantity of light coming into your camera is too low or too high you can adjust the ISO without affecting the creative aspects of your Aperture or Shutter Speed choices. Think of it as a type of multiplier with the ability to double, quadruple, cut in half or quarters the amount of light

But...Aperture and Shutter Speed not only control the quantity of light that comes into your camera, but they both have creative aspects and the choices you make can dramatically change the look of your image, for better or for worse.

In Part 1 of this topic we will focus on controlling the aperture. In Part 2 we will focus on controlling the Shutter Speed.

Aperture

As I discussed in the previous blog, the aperture is the size of your lens opening. The smaller the number, the bigger the lens opening and therefore more light comes in. The bigger the number, the smaller the lens opening, the less light comes in. I know, this sounds completely backwards! It does, and that is how you remember it, because it is the opposite of what you would expect. So, if you want to increase the amount of light that comes into the camera, decrease the aperture. If you want to decrease the amount of light that comes into the camera, increase your aperture or lens opening. Now remember, aperture and shutter speed work together to control the quantity of light that comes into your camera. So this assumes that your shutter speed is staying constant at whatever shutter speed you have chosen (and we will get to shutter speed in the next blog).

Now, I know what you are thinking, "OK Rory, you said that aperture can control the creative aspect of a picture, but all you have talked about is how much light comes into the camera, that is not creative". You are correct. So, let’s continue...

There is a second change that takes place when you change your aperture from low to high or high to low, and that is called the Depth of Field. Depth of Field defines how much of your image is in focus. Meaning, if I am looking down a barb-wired fence and I focus on the third fence post, how much in front and behind the third fence post will also be in focus? If you take a look at the two images below, they were both shot at f4, which means I shot them with a really low depth of field. The subject is in focus, but very little in front and behind the subject is in focus. If you look at the first image, the bottom flower is in focus, the little white flowers above it are a little out of focus, and my niece is really out of focus. The same is true with the second image, Sherylynn is in focus, the sand at the bottom of the image which was closest to me and the waves behind her are completely out of focus, allowing Sherylynn to pop out of the image.

I remember when I first started shooting portfolios for a modeling agency here in L.A. I photographed the first model and turned in the images and the agency seemed genuinely pleased with the results. When I turned in the images from the shoot with the second model, the woman at the agency, who really liked me so she was trying to be tactful, asked me if I could shoot images like the one that was on their wall. She asked if I knew how to put the background out of focus. Up till now I had not been doing that because it never entered my mind to do it. Of course I said, "Sure I can, is that what you are looking for?" Of course that is what she was looking for and I should have been doing that all along because she wants the model to jump out from the background. While driving home I realized I really did know how to do that because I understood depth of field, I just was not applying it. So from that point forward I always shot at a low aperture, usually f4. I know photographers that always shoot at f2.8, but that is a little too much DoF for my taste.

So when I am shooting models and I want a small DoF, I choose a low aperture such as f4 and then find the corresponding shutter speed that will properly expose the image. Now when I am shooting landscapes, I usually want everything in focus so I use a higher aperture such as f11 or f16.

The next blog is going to cover Shutter Speed and its affect on an image. Following that subject, we are going to return to Depth of Field because there are other factors that affect DoF other than Aperture, such as distance and the lens you are using.

If you are interested in seeing more examples of Depth of Field (this is the shameless self-promotion I warned you about), you can go to http://www.westwindmediapub.com/ and purchase a calendar or two as a study aid in DoF, and other aspects of photography. J

Keeping on shooting!

Photography: The Science of Light

In the word “photography”, “photo” means light. Above and beyond everything else, photography is about light. A really well posed subject with a beautiful background can be destroyed by taking in too much or too little light. Now it is true that a lot of compensation can be done using post production tools such as Photoshop, but a lot of post production time can be saved by taking the picture properly first in the camera. In this blog, we are going to talk about the three components of light control, and how each one of them helps to determine the look and feel of your images.


Take 3

There are three settings in your camera that control the amount of light and the matter in which it comes in. They are the aperture, the shutter speed, and the ISO setting. In any given situation there are many, many combinations of aperture, shutter speed, and ISO that will give you a proper exposure. Generally aperture and shutter speed work together and ISO is used as a type of multiplier. The two most important settings are aperture and shutter speed.

Aperture

Aperture is the size of the lens opening. The bigger the lens opening the more light comes in, and the smaller the lens opening the less light comes in. Back in the old days, the aperture was set on the lens itself. Nowadays it is set electronically in the viewfinder of the camera. But regardless, the end result will be the same. The values of the aperture are called f-stops and go something like this: 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, and 22. In writing they look like this: f4, f5.6, f8. How many of these setting you have will depend on your lens. The more expensive the lens the wider range of values it will have. It is the lower end that will change. Some lenses only go as low as 4, while others as low as 1.4. Comparing apples to apples, the lens with the lower aperture settings will cost you more money because it has a bigger lens opening and can let in more light. Using this example, the smallest value, 1.4, is the biggest lens opening and therefore lets in the most amount of light. The largest setting, 22, is the smallest lens opening and therefore lets in the least amount of light. Each value of the aperture lets in twice as much or half as much light, depending on the direction you are taking. So f5.6 lets in half as the light as f4, f8 lets in half the light as f5.6. Or conversely; f5.6 lets in twice as much light as f8, and f4 lets in twice as much light as f5.6. Think of it as, you have a room full of people who have to get out and there is only one door. One of the factors that can determine how quickly the people can get out will be the size of the door opening. The bigger the door opening the more people can get out at one time, the smaller the door opening the fewer people can get out at one time. It is important to understand that aperture and shutter speed are partners, they work together, and an understanding of how they work together is crucial to the understanding of controlling light and of photography.

Shutter Speed

Shutter speed is, how long the shutter stays open. The longer it stays open the more light comes in, the quicker it closes the less light comes in. The values of the shutter speed go something like this: 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, 1/4000. The values are how long the shutter stays open in seconds. So 1/8 means that the shutter stays open an eighth of a second. Like aperture each value lets in half as much or twice as much light as the adjacent setting depending on your direction. Therefore, 1/60 lets in twice as much light as 1/125, and 1/125 lets in twice as much light as 1/250 of a second. Going back to our analogy of a room full of people that need to get out; let’s say that the door is broken and keeps opening and closing, opening and closing. Obviously the longer the door stays open the more people can get out at one time, and the shorter the door stays open the fewer the amount of people can get out at one time.

Now remember I said that aperture and shutter speed work together. When you are adjusting your camera to let in the proper amount of light, you can adjust the aperture (the size of the lens opening), the shutter speed (on long the shutter stays open), or both to control the amount of light that comes in. Think of it like a teeter-totter. Now this analogy will only work if you can remember what a teeter-totter is and how it works. So, you have two people on the teeter-totter, one on each end, and they start to play. As one of them pushes up, the other goes down, and as the lower one then pushes up in turn, the person who was up comes down. Aperture and shutter speed work the same way. You use both aperture and shutter speed to set the camera to let in the perfect amount of light; when you have found a combination of the two that works, realize that it is not the only combination that will work. I could open the aperture by one f-stop letting in twice as much light, and then choose the next highest shutter speed which will let in half as much light. Those two actions will cancel each other out and you will still have the right amount of light, but with a different combination for aperture and shutter speed. You could repeat that process again, giving you another combination of aperture and shutter speed that will work. Aperture and shutter speed work hand-in-hand. So which combination is the best? We’ll talk about that in the next blog.

ISO

What about the ISO setting, formally known as the ISA. The normal values for ISO are 100, 200, and 400. The bigger the ISO the more light is allowed in, the lower the ISO the less light is allowed. Nowadays they can go as high as 6400. Think of the ISO as a magnifier. If you find the perfect combination of shutter speed and aperture and then the sun starts setting and the amount of light starts to decrease, by simply changing the ISO from 100 to 200 you will let in twice as much light without having to change the aperture or shutter speed. Typically this is not played with as much as aperture and shutter speed. Usually if you are outside on a sunny day you will set the ISO to 100, if it is a cloudy day or you are shooting indoors with or without a flash, day, you might set the ISO to 400, letting much more light in. In the 20th century, I love saying that, when we used film, the particles that absorbed the light were a different size depending on whether you were using 100 or 400 ISO. For 400 ISO to let in more light, the particles in the emulsion had to be bigger, causing the images to be grainier. Sometimes this was unattractive, and other times it was more artistic, depending on your taste.

Choices: Which do you adjust and why

OK, so if you can use all three of those settings to adjust the camera to let in the correct amount of light, which one would you change and why? Stay tuned to my next blog, Photography: The creative side of aperture and shutter speed.