Sun is shining in the sky, there ain’t a cloud in sight. It’s stopped raining, and I’m blogging every day, don’t you know?
Since I got a shiny new Sony NEX-5 camera a couple of years ago I’ve started trying to take photos on manual mode a lot more. Taking control of your own focus and exposure settings is a great way to experiment with depth of field, that look you see in professional photos when the background is all blurry. For night-time cityscape shots too, where failing to hold the camera still will make for a very blurry photo, tuning the shutter speed, ISO and aperture settings yourself will help greatly. I don’t pretend to be an expert, but I have been investigating for a while, and I find it fascinating what a difference a couple of settings makes to the overall look and feel of a photo.
Step one is to understand the jargon and what all the different settings at your disposal do. I struggled with this for ages until Xav, one of my friends who runs his own photography business, used a water tap analogy to explain it all to me over dinner in Paris. And that’s how I’ve remembered it ever since.
Imagine all the water flowing through a tap is light coming into your camera. Now imagine the time the tap is open is the shutter speed, because the longer you have your tap open for, the more light your photo will have. Now think of the width of the pipe as your aperture or F-stop, A wider pipe will let more water in than a thinner pipe in the same amount of time. In other words, a wider aperture lets in more light to the camera than a small aperture given the same shutter speed.
Shutter speed is how long the sensor in your camera is exposed to light when you take a picture, so for dark shots you might want a slow shutter speed to give light longer to get into the camera. The interesting thing about shutter speed is how it blurs your image. Lots of sports modes on cameras set a very fast shutter speed because otherwise a fast-moving object will be blurred in the final photo due to it moving while the shutter is open. With a faster shutter speed, the subject won’t be blurred. And this goes for taking photos without a tripod or rest too. If you use a slow shutter speed, i.e. the tap is open for a long time, then if you are shaking the whole frame will be moving. That’s where that blur comes from. So if you’re taking night-time shots without a tripod, try and keep your shutter speed down and opening your aperture instead to compensate, i.e. using a wider pipe instead of keeping the tap open for longer.
Aperture is the size of the gap at the front of the lens that the light can go through. So a higher aperture is a bigger gap. The thing to remember about F-stop is that it’s 1/aperture. In other words, an open/high aperture is represented with a low F-number. Confused, so was I. So here’s a diagram.
Aperture is also the key ingredient to getting a shallow depth of field, those photos with the sexy blurry backgrounds. An open aperture (think low F-number or a wide pipe) gives you a nice, sexy, shallow depth of field. As opposed to a closed aperture (thin pipe, high F-number) that gives a flatter look to pictures. Flat is very good for landscape shots, or when you want to give the illusion that the foreground and the background are very close to each other, called forced perspective. Here’s a great video about how they used forced perspective to portray Gandalf’s height in The Lord of the Rings.
There’s one more key piece to this puzzle and that’s something called ISO. ISO is the sensitivity of the sensor on your camera to light. So you can imagine that a high ISO means it’s very sensitive, and a low ISO means it’s not. In our tap analogy, ISO is like the water pressure in the pipe. A lot of pressure and no matter how wide the pipe, or how long the tap is open, you’re always going to get a lot of water. The caveat here is that high ISO‘s introduce a lot of noise into the photo because the camera is more sensitive to the inevitable inaccuracies in the sensor itself. When shooting, ideally you want to keep the ISO as low as possible to reduce the noise, but that’s not always possible.
This is why you always see so much light in photo shoots and film sets, because ultimately the more light you have to work with, the less you have to worry about ISO noise and shutter speed blur. The less you are restricted, the wider your creative window to play with depth of field, blur (if you want it or not) and other effects. This should also explain why a tripod is very valuable, because then shutter speed can be adjusted freely without having to worry about being able to hold your hand still to get that perfect shot.
In the next blog post I want to show you some examples I’ve found of when you can use shutter speed, aperture and ISO to great effect in different conditions from night time panoramas to fast action to sunsets.
until next time x
p.s. I am aware that I am a few days behind myself at the moment. I’ve realised I’d rather spend a bit longer writing a better post than trying to rush something out every day. I will still be trying to post every day, but if I manage to miss the odd one then I will still be posting 30 blogs, one for every day in April, they just might not all be written in April…