One of the things that helped me most in my progress as a photographer was learning to take control of my camera, making it do what I wanted it to, rather than just letting the camera decide. Hopefully I can pass this on, with some tips on how to move away from auto settings.
The first thing you need at this point is a basic understanding of shutter speed, aperture and ISO, so you can make informed decisions on how to set up your camera. These three settings are often described as the exposure triangle, as each one contributes to the amount of light that gets into your camera. One common analogy is filling a bucket of water, the ISO is how big the bucket is (how much light you need), the aperture is how fast you pour the water in and the shutter speed is how long you’re pouring for. You always need the same amount of water (or light) to fill the bucket, but you can add it quickly or slowly. The shutter speed and aperture are often chosen for creative reasons, so I’ll explain what they all mean and why you would choose certain settings below.
This is how long your camera leaves the shutter open for. Normally you want this to be a fairly short time, as leaving it open longer will make things blurry. A rough guide if you’re shooting handheld is that your shutter speed should be no slower than 1/focal length of your lens. For example shooting at 200mm you should be 1/200 or faster, if you’re shooting wider at 50mm then you can get away with a slower shutter speed of 1/50. Using a tripod can let you go slower than this which means more light will get into the camera which is great for low light situations, but then you have to consider whether the subject is moving. Sometimes you are forced into a very fast shutter speed to get the right photo, sometimes you want it very slow for artistic effect, but there is always a trade off to changing any setting on your camera.
Time for some examples. If you’re photographing birds, you’ll want to be at 1/1000 or even faster to keep the moving wings nice and sharp. Motor racing would be around 1/250 so you can get a nice blurred background as you pan to follow the car and give a feeling of speed. For a waterfall you can go two ways, if you’re freezing the water you’ll need to be above 1/100, anything from there to 30 seconds will show different amounts of movement and give a nice silky texture to the water. Photographing a landscape at night you’d need a long shutter speed to let enough light in, up to 30 seconds or so, going past that you’ll start to see stars as lines as you’re capturing the rotation of the Earth. Sometimes you might want to use a long exposure to purposefully blur things that are moving, that’s a whole subject on it’s own which I covered at Long Exposure Photography
So to round up, faster shutter speed is less light but a nice sharp image. Slower shutter speed is more light, but will start to get blurry, either due to the subject or the camera itself moving.
In the photos of Loch Ness below you can see that the 30 second shutter speed has been used creatively to make all the ripples in the water blur together and give a simple minimal photo. The observant among you might notice the aperture and ISO don’t change between the two images, so you’d expect the 30s version to be overexposed. I used a very dark 10 stop neutral density filter here to allow me to get a longer exposure, which is covered in the long exposure tutorial linked above.
This is how wide the hole is through which the light passes in your lens, the smaller the number is the wider the hole, a high number means a very narrow hole. It’s as obvious as it seems, bigger hole equals more light. The trade off here is that a bigger hole also means shallower depth of field, this is how much distance front to back which can be in focus at one time. This is often used on purpose to get nice soft backgrounds in portraits, but if you’re shooting a landscape you’ll want plenty of depth of field in order to get everything sharp from the foreground to the horizon. Depth of field is reduced by focussing close to the camera or using long lenses, with a wide angle lens or focussing a long way away you can use a wider aperture while still getting everything in focus. Usually the largest and smallest apertures lack sharpness and your lens will perform best between around f8 and f11.
Some examples again. Portrait photography you often want the widest aperture your lens can get for a nice soft background, typically f1.4 to f3.5. For group shots you need more depth of field to get everyone in focus, try around f5.6. If you’re shooting a landscape with foreground interest you might need to go up to f16 or above to get everything in focus, but look into hyperfocal distances or focus stacking if you want to work within a range where your lens is at it’s sharpest. For macro you need the highest aperture you can use as depth of field is always very shallow when you’re working on that scale. f22 or above may also be the way to go if you want a slow shutter speed for creative reasons, as it will let less light in so you need the shutter open longer to get the same exposure. For photographing the night sky you want to go as wide as you can as you need to get as much light in as possible before the stars start getting blurry, as mentioned above if you’re using a wide angle lens and focussing a long way away the depth of field is less of an issue.
Aperture is in the lens not the camera, so when you choose a lens this is an important spec to look for. Lenses always list the widest aperture they can achieve. Usually zooms aren’t as good for this and will list two numbers, an example would be f3.5-5.6 on an 18-55mm lens, this would mean at 18mm the aperture can’t go wider than f3.5 and at 55mm it is limited to f5.6, so you might struggle in low light and won’t get that beautiful blurry background in portraits. You can get zooms that have good apertures but they will be more expensive, the Tamron 17-50mm I use for most of my work has a widest aperture of f2.8 at all zoom lengths, which is about the best you get on a zoom lens. For wider apertures than that you need to look into prime lenses, these have a single fixed focal length so they have to make less compromises in the optics. A very popular one is the Canon ‘nifty fifty’, a 50mm lens with an f1.8 aperture for a very reasonable price. Prime lenses are available in plenty of focal lengths, normally with apertures between f1.4 and f2.8 – the wider the aperture the more you will pay!
To sum this up, wider aperture is more light but less depth of field so part of your photo may be out of focus, narrow aperture lets less light in, but will keep the subject sharp from front to back.
See in the roses photo below, with a wide aperture of f2.8 the blurry background puts more focus on the single rose, with less distractions. At f22 all the other flowers are in focus and there’s a lot more detail in the garden behind which looks messy, the shutter speed was also much slower which meant I had to use a high ISO for these shots.
The last of the three settings, ISO is the sensitivity of your camera to light, in the old film days you would select a roll of film with an ISO or ASA value, now you can just choose this on your camera. This doesn’t really have a creative purpose like the two above, it’s simply a trade off between how much light you need vs how noisy your image is. As a general rule, always choose the lowest ISO you can which lets you expose the image correctly once you’ve got a suitable shutter speed and aperture, this allows you to get the best quality image your camera can produce. Shooting still life, or landscapes in good light on a tripod, there should be no reason to go above ISO 100, if you’re taking photographs handheld in poor light, shooting wildlife with a very long lens, or capturing the night sky, you will have to start increasing the ISO. This is where the quality of your camera can make a huge difference, sensor size and quality will define how well your photos come out with high ISOs. On a cheap point and shoot anything from ISO 400 might start to look like a horrible grainy mess, with a medium level DSLR or mirrorless camera you can get away with ISO 800-1600, get to the top of the range DSLR bodies and you can happily shoot away at 3200 or more! Try taking the same photo with each of the ISO settings on your camera then look at them fully zoomed in on your computer and see the difference it makes, decide which is the highest ISO you’re happy with in terms of noise and keep that in mind when you’re setting your camera up. Remember that noise can be improved in the edit, whereas if you set your ISO too low and as a result the shutter opens for longer and the photo is blurry, there’s nothing you can do to save that later.
An easier summary here, low ISO number is less light but a cleaner image, higher ISO number is more light and more noise.
You can see the amount of noise present in the orchids below at ISO 3200 from my Canon 500D, imagine how bad this is when you’re looking close, you couldn’t use this for a large print as the quality wouldn’t be good enough. I normally limit myself to ISO 1600 on that camera and stay at ISO 800 or below if I can.
A stop is a doubling or halving of light, so we can use it to talk about how changing each of the settings above affects the exposure of your photo. This is quite an important concept to get to grips with as it’s the foundation of the exposure triangle concept. Stops can be added or removed by changing any of the three settings we’ve just discussed, and that’s how you balance your exposure.
Changing shutter speed from 1/50 to 1/100 will halve the amount of light getting in (minus one stop), going the other way from 1/50 to 1/25 will double the amount of light (plus one stop).
Aperture is a slightly less obvious one as the actual numbers don’t double or halve, going from f4 to f5.6 actually halves the amount of light (minus one stop) whereas going from f4 to f2.8 doubles the light (plus one stop). The reason for this is is a bit complicated, but most cameras adjust aperture in 1/3 of a stop increments, and the handy chart below shows the common full stop values.
ISO thankfully makes it easy again, increasing ISO 200 to ISO 400 doubles the light (plus one stop), changing from ISO 200 to ISO 100 halves the light (minus one stop). ISO settings are usually only adjustable in full stops.
The chart below shows full stop increments of each of the three settings, with the left settings allowing more light in, then getting darker to the right. I’ve also included the effects you get from changing each setting. If you go back to my Loch Ness photos in the shutter speed section above, I mentioned I used a 10 stop neutral density filter on the second one to take the exposure from 1/25 to 30s without changing any other settings, you should see on the chart below that this change in shutter speed is almost exactly 10 stops.
So why do you need to know this and how do you put it to use?
Say you’re taking a cloudy landscape photo, you’ve got it exposed perfectly using f8, a shutter speed of 1/100 and ISO 100, you take the photo and review it to find the background is a bit out of focus so you need to adjust your aperture to get more depth of field. You change the aperture to f16, which is taking away two stops of light, this means to maintain your exposure you need to add two stops of light some other way, either increasing the shutter speed or the ISO. Two more stops of shutter speed would take you from 1/100 to 1/25 (double the time and double it again), this might be a little bit slow as you could see trees blurring as they blow in the wind, or the camera might be moving a bit if you’re shooting handheld. You could add two stops from ISO and leave the shutter speed as it was, which would go from ISO 100 to ISO 400 (double and double again). Alternatively why not add one stop from each, so your shutter speed would be 1/50 and ISO 200.
All the settings mentioned above give the exact same exposure, so you actually have quite a lot of choice on each photo on how you want the settings to balance out in order to get the same amount of light in the camera. On auto your camera is just picking all those for you, but how does your camera know how you want the photo to look?
To go to the extreme ends and show how much effect this can have, f22, 1/8 and ISO 100 is the same amount of light as f22, 1/125 and ISO 1600, which is the same as f2.8, 1/500 and ISO 100. The difference this makes to your photo is huge, the first one might be blurry because the shutter speed is too slow, the second one would be noisy because the ISO is high and the third one wouldn’t all be in focus because the aperture is very wide. If none of those settings work for your subject you could balance this instead with f8, 1/125 and ISO 200, again the exact same amount of light.
OK, so how do I set up my camera?!
If you’ve taken all that in, you now know what you need to make the decision on what is important to you when you’re taking each photograph.
The aim of this tutorial is to get you away from automatic modes on the camera so that usually leaves 3 options, full manual, aperture priority (Av) or shutter priority (Tv).
Full Manual Mode
Full manual speaks for itself, you need to choose the shutter, aperture and ISO yourself, this is great when you have time to get it right and have consistent conditions to work with, for example studio photography where you are shooting the same subject with control of the lighting. It’s daunting to start with though and can slow things down or cause problems if you need to get the photo right first time. The camera will have a light meter built in, so you’re not completely on your own here, choose your ideal settings and hold the shutter button halfway down, there’ll be a bar on the screen looking a little like this:
If that marker at the bottom is to the left it’s underexposed, on the right you’re overexposed, you can then adjust settings to get more or less light until it’s in the middle.
I’d recommend starting with the priority modes as they do some of the hard work for you, I spend most of my time in aperture priority (Av) so let’s start there.
Aperture Priority Mode
Aperture priority means you set aperture and ISO then the camera works out the shutter speed needed to expose the photo correctly. This is great as the camera is constantly adjusting for you which speeds things up a lot. If you know you want the blurriest background you can get then just turn the aperture right down and walk around shooting happily all day, if you’re taking landscapes set the aperture up around f11-f16 and snap away.
Make sure you do keep an eye on the shutter speed your camera is selecting for you while doing this, if you’re using a wide aperture in good light you can probably set your ISO to 100 and have no issues. If you’re trying to shoot wildlife with a 200mm lens at f8 to get some background detail in focus and the light isn’t great you might find the camera is choosing 1/50 shutter speed to expose correctly and things are getting a bit shaky, in that case turn the ISO up two or three stops and try again.
You would most likely choose shutter priority when this is the most important consideration, so sports photography where you need to freeze action, motor racing where you want to set a pretty specific shutter speed to get the car sharp but blur the background as you pan your camera to follow the car, or wildlife where you need a nice fast shutter to capture fast moving animals.
Bear in mind that as above you still need to keep an eye on what the camera is doing to get the exposure right. Your most likely problems here are that it sets the aperture too wide and some of the things you want in focus get a bit blurry as they’re outside the depth of field, or the aperture is at its widest and you’re still not getting enough light in to expose correctly, this will be shown by the marker on the exposure bar pictured above being far over to the left and possibly flashing. You’ll also soon notice when you review your photo and everything is dark. You can fix this by increasing ISO, or slowing down the shutter speed you’re aiming for and trying again.
I hope this has helped explain some settings on your camera and how you can use them to take control of how your photos come out, let me know in the comments if you’ve got any questions!