# how does aperture and shutter speed work?

Please help! I need to know how to work this two together, can you guys write me some examples? thank you all :)

Relevance
• 10 years ago

The aperture controls how much light gets through the lens in a certain amount of time. The shutter speed controls the amount of time the shutter is open. The ISO speed is how 'fast' the film is, i.e. how sensitive it is, and that's also part of the equation.

Suppose, for instance, you are taking pictures in bright sunlight with a film that is ISO 100. That means you set the aperture to f:16 and the shutter speed to 100 (actually 1/100 of a second) and you get a good exposure in bright sunlight. Aperture f:16, shutter speed at ISO speed, in bright sunlight, proper exposure.

Now suppose you want to use a shutter speed of 1/200 of a second. That's half the time, so you use the next BIGGER f stop, f:11. Or you could go the other way, set the shutter to 1/50, which is twice the amount of time as 1/100 so you use the next -smaller- f stop, f:22.

Every shutter speed is twice as much as the one to the left, half as much as the one to the right. Every f stop is half as much as the one to the left, half as much as the one to the right. So once you have the proper exposure you have a range of choices.

Now why would you bother to change them? Easy. A fast shutter speed can be used to freeze action, while a slower one can give you some blur (sometimes you want it). A small f-stop gives you more depth of field and a larger one gives you less, so sometimes you want to blur out the background, other times you want it in focus. If you understand how to use these controls you can control these things!

For shade you open up two or three stops (either shutter or f-stop). Inside, or in twilight or dusk, you really need a light meter. (Some people seem to be better at guessing than others.)

Also modern digital cameras, you can change the sensitivity of the 'film' with another control. So if you want to use both a small f-stop and a fast shutter speed, you can crank up the ISO. If you are in bright sunlight and you want a wide f-stop and a slow shutter speed, you can turn the ISO down. With film cameras you have to change the film. A fast film gives you more possibilities indoors or in dark shade. A slower film is harder to use but the grain is finer and the tones are nicer.

• June
Lv 4
4 years ago

think you have some good answers already - hopefully they are helping. Here is an example on how aperture and shutter speed work together. Let's say you were taking a portrait and were shooting at f8 and 1/60 second. Then the wind picked up but the lighting stayed exactly the same. You could continue to shoot F8 and 1/60 but you might see some blurring of the hair due to the wind. You like the blowing hair but want it frozen, so you change the shutter to 1/125. In order to maintain the correct exposure, your aperture changes to F5.6. This allows the same amount of light to strike the sensor - giving the same exposure. As far as getting streaks of light from cars, the key is the shutter speed. Set your shutter to something like one second and the camera will figure out the aperture for you. If the streaks are too long, try a half second. If the image is overall too light, you might need to use manual exposure and set both the aperture and shutter yourself. Also, with these shutter speeds you definitely need to be using a tripod. Good luck!

• 10 years ago

The aperture in a real camera is a series of pieces of metal close in a circular fashion like the cover over the Stargate in the show.

It controls how much light enteres the camera. If the aperture is ver wide open then fewer things are in focus. This will have a lower number.

Wide open low number, more light.

A smaller aperture has a larger number and makes more things in focus.

Small opening, bigger number , less light.

The shutter speed is how long the film or sensor is exposed to light. Usually very quick.

You use the aperture to determine how much depth is in focus. At f5 only the main subject you have focused on will be focused. At f22 the main subject and some things in front and behind will also be focused.

You use the shutter speed to capture movement. At 1/1000 most actions will be frozen and sharp. at 1/60 most movement will be blurred.

You use the two in conjunction to achieve the desired effect. In a sporting event you are photographing a person kiskcing a goal. You can open the aperture all the way as you only want the main subject in focus and you need lots of light to shoot at 1/1000. In a museum you at shooting an ancient vase. You want to whole vase surface focused so you shoot at f30ish and you need to expose the film for 1/5 less light so it takes longer.

You cna then use the combination to make different effects.

• EDWIN
Lv 7
10 years ago

The "Exposure Triangle" is made up of the shutter speed, aperture and ISO.

ISO is a measurement of the sensitivity to light of a light sensitive surface, either film or digital sensor. A low ISO - 80, 100 - is very insensitive and requires more light. Its used outdoors on a sunny day and gives the best results, having smaller grain on film or less digital noise with digital. A higher ISO - 200, 400, 800 - is more sensitive and requires less light the higher the number. Its used indoors or for sports/action. With film there's more grain and with digital, more noise.

The aperture (aka f-stop) controls how much light is admitted by the lens. Traditional f-stops are expressed in full stops on your lens - 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32. This is an inverse relationship - the smaller the number the bigger the opening formed by the movable blades of the diaphragm inside the lens. So f1.4 is a very large opening and admits the most light. If we "stop down" to, say, f16 we'll have a tiny opening and admit very little light.

The shutter controls the amount of time the light admitted by our lens is allowed to expose our film or sensor. Both the ISO and the f-stop affect our shutter speed. Suppose its a sunny day and we're using ISO 100 and decide to use f16. Our shutter speed will be slower than it would be if we used ISO 100 and f8. The venerable "Sunny 16 Rule" shows this relationship. It states: "On a sunny day, set your aperture to f16 and your shutter speed to 1/ISO." This chart shows the f-stop/shutter speed relationship:

ISO 100

f32 @ 1/25 sec.

f22 @ 1/50 sec.

f16 @ 1/100 sec. "Sunny 16 Rule"

f11 @ 1/200 sec.

f8 @ 1/400 sec.

f5.6 @ 1/800 sec.

f4 @ 1/1600 sec.

f2.8 @ 1/3200 sec.

f2 @ 1/6400 sec.

f1.4 @ 1/12800 sec.

You can easily see how admitting more light - opening up the aperture - affects shutter speed at our given ISO. At f11 twice as much light is admitted as at f16; at f8 twice as much light is admitted as at f11, etc. As we admit more light our shutter speed increases to compensate.

The more light admitted the faster our shutter speed.

You can also see how admitting less light - stopping down the aperture - affects shutter speed at our given ISO. At f22 1/2 as much light is admitted as at f16. With 1/2 as much light our shutter speed decreases to compensate.

The less light admitted the slower our shutter speed.

The f-stop used also affects our Depth of Field (DOF) but that's another discussion for another day. If you'd like to explore DOF this site will help: http://www.dofmaster.com/dofjs.html This site also will help: http://www.illustratedphotography.com/photography-...

Source(s): 38+ years of learning about and enjoying photography.
• 10 years ago

On this site is an on screen simulator for the same;

http://www.kamerasimulator.se/eng/?page_id=2