Hey guys – If you’re joining me for the first time before you continue please check out “Understanding your first DSLR”
OK… now that we’ve gotten that out of the way. Welcome back to my blog this is part 2 of understanding your first DSLR. Today we are going to talk about ISO, Aperture and Shutter Speed . I want you to familiarize yourself with these settings and get comfortable with them. It can become very difficult to take “good ” pictures without having a solid understanding of the Exposure Triangle or as I like to call it the Three Queens of Photography.
Most DSLRs have an “Auto” mode which allows the camera to automatically pick the correct shutter , aperture and ISO settings. However, this mode will limit what you can and want to achieve with your camera. In certain cases the camera is going to try and guess the correct exposure by evaluating the amount of light that will pass through your lens.
If you take the time to understand the exposure triangle this will allow you as the photographer to take full control over your camera and push it to its limits to take great photographs.
So lets jump right in and quickly review the exposure triangle to refresh your memory or give you some insight if you are unfamiliar . I’m going to make this SUPER EASY for you to remember .
- SHUTTER SPEED – the length of time the shutter is open to allow light into the camera sensor. The shutter speed is typically measured in fractions of a second meaning that a slow shutter speed will allow MORE light into the camera sensor. This is best for low light settings and night photography. A FAST shutter speed will help freeze motion.
- examples of shutter speeds : 1/15 (1/15th of a second) 1/30 , 1/60 , 1/125 (1/125th of a second ) etc
- APERTURE– Think of aperture as a hole within the lens where light travels into the camera body. The LARGER the hole =MORE LIGHT / SMALLER hole =LESS LIGHT into the camera sensor. Aperture also controls your depth of field ( the portion of the scene that appears sharp and in focus) if you have a SMALL APERTURE= LARGE DEPTH OF FIELD / LARGE APERTURE= SMALL DEPTH OF FIELD. Aperture is usually expressed in “F” numbers aka “Focal ratio”
- Examples of F-Stops: f/1.4 , f/2.0 , f/2.8 , f/4.0 ,f/5.6 , f/8.0
*Side Note A Lens with an Fstop of 1.2-2.0 will give you great control over depth of field for selective focus and also benefits working in low-light.
- ISO- Think of this as a way to brighten your photos if you can’t use a longer shutter speed or a wider aperture. ISO is usually measured in numbers , a LOW NUMBER = DARKER IMAGE / HIGHER NUMBER = BRIGHTER IMAGE . However, its very important to remember that the HIGHER you go in ISO the visibility of graininess/ noise will show in your image .
Examples of ISO
- ISO 100 (low ISO)
- ISO 200
- ISO 400
- ISO 800
- ISO 1600
- ISO 3200
- ISO 6400 (high ISO)
I hope at this point you have a better understanding of the Exposure Triangle. I’m going to try my best in helping you understand how they all work together. In order to have a good understanding we need to understand what happens within the camera when the picture is taken.
Now as you point your camera at a subject and press down on the shutter button the subject goes through your camera lens in a form of light. If your subject is well-lit then you will have plenty of light traveling through your lens. When light passes through your lens it goes through many optical elements made of glass then it goes through your lens = APERTURE.
Once light goes past the lens aperture it will then hit the shutter which acts like a window that is closed at times but opens when needed. It only takes the shutter a quick second to open letting the light hit the camera sensor for a certain amount of time. This time is called SHUTTER SPEED and it can be short ( up to 1/8000th of a sec) or long (up to 30 seconds). After all of this happens the sensor will gather the light allowing your ISO to brighten up the image if necessary. Then the shutter will close and block the light from reaching the sensor.
*Side Note : Grain and image quality problems may be more visible at this point.
In order to get an image properly exposed so that its not over exposed or under exposed – the shutter speed , aperture and ISO need to work together as a team. Lets say it’s broad day light with plenty of sun what will happen if the lens aperture / hole is very small ????? A lot of that day light gets blocked out – that means the camera sensor would need more time to gather the light. What needs to happens in order for the sensor to collect the correct amount of light? That’s right, the shutter would need to stay open longer so with a very small lens aperture we would need more time I.E longer shutter speed for the sensor to gather light to produce a properly exposed image.
Now what happens when the aperture is very big ?? MORE light will hit the sensor so in turn we would need a much shorter shutter speed for the image to get properly exposed. Make sense ??? If your shutter speed is too low the sensor will get way more light than it actually needs and you will over expose your image. In contrast, if the shutter is too high you will not gather enough light and your image will be too dark or under exposed. In some cases some photographers prefer to photograph under exposed in order to see the information in the image if they are in a low light situations because you can adjust this in post (photoshop).
So lets try and practice a real-life example. Pick up your camera and change the camera mode to “Aperture Priority” Now set your “lens aperture” on your camera to the lowest it can possibly go such as f/1.4 for fast lenses or f/3.5 for slower lenses. Set the ISO to 200 but make sure that “AUTO ISO ” is turned off.
Now that we have the settings all set up – point your camera at any object that is not a light source (for example closet, wall, doors) then i want you to half press your shutter button to get the correct focus. We are letting the camera determine the correct exposure settings. DO NOT MOVE your camera – keep it pointed in the same spot at the same subject.
If you look inside the camera viewfinder or on the back of the LCD you will see several numbers. One number should show you the aperture which should be the same as the number as what you set in on previously- then it should show you shutter speed which should be a number such as 1/125th and last your ISO aka the sensor for 200.
Remember to write these numbers down on a piece of paper and then take your picture. When the picture pops up on your viewfinder it should be properly exposed. Not too bright and not too dark. Now switch your camera to Manual Mode and set you manual settings to the same as what you wrote down earlier ( the lowest your lens will go 3.5).
Then set your shutter speed(1/125th) and keep your ISO (200) the same . Don’t forget to make sure you’re using the same subject in the same spot with the same lighting. Now take the picture- your results should look fairly similar to the picture you took earlier however, this time you are manually setting your shutter speed instead of letting the camera guess for you.
This time around we are going to block out the amount of light passing through the lens by INCREASING THE APERTURE. lets try and see what happens.. Go ahead and increase your aperture to a much larger number like 8.0 still keeping the rest of the settings the same. Once again point your camera at your subject and take another picture. Lets take a look…. So what happened? Your image should be too dark or underexposed.
Why do you think this happened??? Because we blocked out a portion of light from hitting the sensor and we also did not change the shutter speed. In turn, The camera sensor didn’t have enough time to gather the light = underexposed image. If you decreased the shutter speed to a smaller number this would not have happened…
Does this make sense? Do you understand the relationship ?
So now lets go back- set your camera to what is was before (smallest number) but this time around i want you to decrease your shutter speed to a much smaller number. Now try taking another picture- what happen this time ?
Your image should have come out over exposed with parts of your image being too bright. This time you let your lens pass through all the light it can gather without blocking it then you let your sensor take in all this extra light (more than it would need ) just by decreasing the shutter. This alone kind of gives you an idea of how shutter and aperture work together. But now your wondering where does ISO fit in or play its part.
So far in each practice we’ve kept the ISO pretty much the same (200) but keep in mind ISO means “sensor brightness”. The lower the numbers the lower the brightness if that makes sense.Higher numbers means higher brightness. If you decided to change the ISO from its 200 to lets say 400 your going to end up making your image twice as bright than it was originally. Aperture f/3.5, shutter 1/125th of a second ISO 400= meaning you would need twice less the amount of time to properly expose your image.
TRY IT. take the example we tried earlier ( the one you wrote down ) however, this time your going to multiply your shutter by two and set the number then set your ISO 400. Your image should look the same as the first image you took earlier – now increase ISO 800 AGAIN you will need to double your last shutter speed from 1/125th to 1/500.
By now you can see that increasing ISO from 200 to 800 this will allow you to shoot at a higher shutter speed and being that we’ve increased the shutter from 1/125 to 1/500 that alone is plenty of speed to freeze motion . Just always keep in mind the more you increase your ISO the higher of a risk you take with noise/ and grain being visible in your image..
I know this was a lot to take in and it may still seem a bit confusing but i promises if you practice the example i gave you will be on your way to taking some amazing images. This is how the Three Queens work together to give you the best exposure for your image. I highly recommend to keep playing with your settings – change the aperture, shutter, and ISO and see what time of crazy effects you can get.
Dont for get to hashtag me #NoelleCoPhoto and let me see your practice examples.