The Effect

As I mentioned in my previous post, shutter speed is the length of time that the shutter is open and passing light onto the camera’s film or digital sensor. When most people use their cameras, they use them in an ‘Auto’ mode, where the camera adjusts all of the settings for them automatically. Typically, only the amount of lighting affects the shutter speed when in automatic mode. When the lighting is darker, the camera automatically adjusts for a slower shutter speed, allowing as much light in as possible. However, you can benefit from adjusting the shutter speed in more ways than just the surrounding light.

In almost all situations where your subject is a live being (human, animal, insect, etc.), a slow shutter speed will result in unwanted blurring in your photo without making your subject stay still for an extended period of time while the shutter is open. This doesn’t work too well when your trying to take pictures of your children’s soccer game. But when you’re taking pictures of non-living beings (notwithstanding plant life) an extended shutter speed may give you that “pizazz” in your photographs that separates you from the rest.

One example of this is photographing fireworks. If you were to use a slow shutter speed the firework explosion will look frozen, and may not capture the overall look and feel of the explosion. Take the examples below:

You’ll notice the largest impact of this fast shutter speed in the second picture, where the shot was initiated at the very beginning of the explosion. Although the shutter speeds on these two shots were 1/2 and 1 second respectively, each only captured a very small portion of the firework explosion.

Now, look at a couple of shots with longer shutter speeds:

You’ll notice, in these two shots, long streaks coming from the fireworks, creating a far better shot than the first two images. Both of these shots were taken with a shutter speed of approx. 2 second.

Another subject that a longer shutter speed can make your shots look better is water, such as a waterfall or river. Just like with the fireworks, a fast shutter can cause the water to “freeze”, losing the feeling of motion in the shot. Take the following example:

The water in this image appears frozen, and although you know the water is falling its effect is lost in this shot. This image was shot on a very sunny day, at ƒ/10 with a shutter speed of 1/400.

Now, take the following example shot at ƒ/36, with a shutter of 1/13.

You’ll notice that because the shutter was open longer, the water blurred slightly as it moves while the shutter is open. This gives the shot a feeling of motion.

You’ll also notice that because the shutter was open longer, allowing more light in, that the camera had to adjust the aperture size to ƒ/36, a very small opening, to compensate for the lengthened shutter speed.

How To?

There are two ways to alter the shutter speed of your camera. One is more difficult, and that is the Manual setting on your camera. This setting allows you to chose all aspects of the settings in getting your shot, shutter speed, aperture setting, etc. I do not recommend using the Manual setting for these types of shots.

The setting I used is the “Shutter priority” setting. Shutter priority allows you to chose the desired shutter speed, while allowing the camera to automatically adjust the other settings of the camera, such as the aperture size. You’ll want to check your camera’s manual to find out exactly how to use your camera in shutter priority mode, but I’ll provide the steps for the Nikon D40, which may be similar for your camera.

To switch the camera into shutter priority, look for the Mode dial on your camera. Most dSLRs have the Mode dial on the top of the body. Point-and-shoot cameras may be on the top or back side, or they may not have one at all, requiring the use of the on-screen menus. If your camera has a Mode dial, it will look similar to this:

To get this particular Mode dial (as well as on Nikons) into shutter priority mode, you would need to select “S”, for Shutter. As far as I know, Canon still uses the symbol “Tv” to represent shutter priority on their Mode dials. I then select my desired shutter speed by holding the “Info” button (near the shutter release button), and toggling the real dial to the left (longer shutter speed) or right (shorter shutter speed). Once the desired shutter speed is selected, release the “Info” button, and frame and shoot your picture as you normally would.

Once finished shooting, remember to switch your Mode dial back to “Auto” or to “P” (Program Mode), or else all of you future shots will remain in shutter priority.

Remember, I provided instructions for doing this on a Nikon D40 dSLR. Check your camera’s manual for directions on using your particular camera model.

Welcome

First and foremost, I’m an amateur photographer. If even that. I’ve always enjoyed taking photographs, and could get some pretty good ones with my older Canon S3 point-and-shot. Recently I got a Nikon D40 and started going around the Dayton area and getting some shots. Colleagues and friends of mine have said that I take pretty good pictures, and have asked for pointers here and there. So, I thought I’d create a blog of tips, tricks, and good photography spots I find. My gallery is located on my website, just click the Gallery link. If you like my photographs, great, maybe you’ll enjoy my blog as well.

The Basics

For my first post I’ve decided to discuss some of the very basics of photography, and the terms associated with it.

Shutter Speed

When your camera is idle a piece of the camera called the shutter is closed and prevents light from hitting the film or digital sensor. Think of this as you having your eyes closed. Once you press the shutter release button to take your picture, the shutter opens up and allows light to expose the file or digital sensor. The length of time the shutter is open is the shutter speed, noted in seconds. Shutter speeds range from thousandths of a second to, in theory, infinity, but vary depending on your particular camera model. The Nikon D40 has a range from 1/4000 to 30 seconds. Some cameras, including the D40, have what is called “bulb” mode, where the shutter will remain open as long as the shutter release button is pressed. Once the button is released, the shutter closes.

If your camera has a manual, or semi-manual mode (technically called Shutter Priority), you may be able to determine the shutter speed yourself, without the camera doing it automatically. When you adjust your settings there are a couple things to keep in mind

1. If the number does NOT have a single (or sometimes double) quote, the number represents is the denominator in a 1/x of a second shutter speed. So, if you see 1000, it means the shutter speed is 1/1000th of a second; 50 means 1/50th of a second.
2. If the number does have a quote, the number represents full seconds of the shutter speed. So, if you see 1″, the shutter speed is 1 second.

Shutter speed is important because it is a part of the equation on determining how much light passes onto the film. The longer the shutter is open, the more light that is exposed onto the film. In low light situations, a longer shutter speed is necessary to allow enough light onto the film to capture a good image. In high light situations, a slower shutter speed is necessary to prevent too much light from being captured.

It is also important to remember that the longer to the shutter is open, the more motion will have an effect on your shot. This can have a negative effect, but can also have a positive effect depending on what your looking for in your shot. You must also remember that natural human movement will affect your shots as you hold the camera. You may think that you’re holding the camera very steady when in fact your body is moving just enough to cause a blurred image, sometimes called “camera shake”. Since everyone is different, I can’t give you an idea on how slow of a shutter you can manage without needing a tripod. If you’re using a digital camera, great. You’re able to experiment with your shots to determine your limit without having to waste film.

Focal Length

The focal length is the length, measured in millimeters (mm), between the middle of the lens to the film or sensor.

The main thing you need to take from focal length is that the higher the number, the more magnified your image will be.

According to one reviewer, the equivalent focal length of the human eye is about 50mm. I’ve never tested this, but it sounds about right. What this means is if you look at a scene without your camera, then with your camera at 50mm, you should see the same image.

Focal length is one aspect that SLR, or single-lens reflex, cameras excel because the lenses are detachable and higher or lower focal length lenses can be added. For example, I use two lenses with my D40, an 18-55mm and a 55-200mm. In contrast, most consumer cameras have fixed lenses that can not be changed and focal lengths are fixed within a certain range. For example, the Nikon Coolpix 8-Megapixel L18 camera has a focal length range of 35-105mm, which seems to be pretty close to standard on present day digital point-and-shoot cameras.

One term you hear a lot is the “zoom” power of a camera, mostly the “optical zoom”. This is really just a marketing effort by the camera manufactures. All the “zoom” number represents is the highest focal length of a lens divided by the lowest focal length. So, with the Coolpix example from the previous paragraph, it has a 3x zoom (105 / 35 = 3)

An important photographic note to mention is that the higher the focal length you use when taking a picture, the lower distance relationships are between near and far objects. Take the following two examples:

The first image was shot at 18mm, while the second image was shot at 55mm. You’ll notice that the “BGSU Alumni” mug is very close to the same size in both shots; however, the blue cup and door appear much farther away in the first image, even though they were in the same location for both shots.

This effect is exposed in Hollywood, by use of the Dolly zoom where the camera moves away from a subject (via a dolly), while simultaneously zooming to make the subjects occupy the same amount of space within the frame. An stop-frame example of the Dolly zoom, provided from Wikipedia, pay close attention to the size of the subjects within the frame and the size of the vehicles in the background:

One thing to look for in higher focal length lenses is something Nikon calls “Vibration Reduction” and Canon calls “Image Stabilization”. Because of minute motions your body makes, having a powerful zoom can cause severe “camera shake”. To compensate for this, lens manufactures develop lenses that have internal mechanisms to compensate for this shake, allowing for the exposure to remain steady.

I’ll discuss more advanced considerations when dealing with focal lengths on digital cameras in a later post.

Aperture/F-Number

Another device on your camera that controls the amount of light to the exposure is the aperture of your lens. The aperture is basically a hole in your lens through which light passes, the smaller the hole the less light that can get in.

The aperture size is measured by the f-number (ƒ/x), and mathematically is the ratio between the focal length (and the width of the opening. What this means is that the smaller f-number, the wider the opening. In simple terms, lets say you have a 10mm lens and your f-number is set to ƒ/1, the width of the opening of the aperture would be 10mm. The numerator, ƒ, represents the focal length, so in the previous example 10/1 = 10. What this also means is that the actual width of the aperture changes, even when the f-number is the same. Take the following:

1. A focal length of 55mm at ƒ/5.6, the width of the opening would be approx. 9.82mm.
2. A focal length of 100mm at ƒ/5.6, the width of the opening would be approx. 17.85mm.

All lenses have a minimum and maximum aperture size. A visual example of aperture is shown here:

You can see the opening in the first image is very small, and the second image is wider.

You may be asking, “Why does this matter?”. It matters because of a concept know as “depth of field”. Having the aperture open wide (small ƒ-number), only the subject that is being focused actually shows in focus. Anything closer or farther from the subject will become blurred, known as having a small depth of field. When you decrease the aperture (large ƒ-number), more objects become focused, a large depth of field.

Take a look at the book in the background.

The first image has a large depth of field, and was taken at ƒ/36. The second image has a small depth of field, and was taken at ƒ/5.6. It should also be noted that because less light is able to get in at ƒ/36 (because the aperture has a smaller opening), it required a 6 second shutter, where the ƒ/5.6 only required a 1/6 second exposure.

Hopefully, this basic information about photography will give you some ideas to make your pictures even better than they already are