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Many photographers don’t like using the high ISO settings on their digital cameras. That’s because they remember what using high ISOs on early digital cameras was like – terrible. But things have changed. Any camera made in the last ten years will give you a decent image quality at a high ISO. It’s time to stop being afraid of high ISO and start thinking about the creative benefits it gives you instead.
What is a high ISO?
The definition of high ISO has changed as digital cameras get better.
Back in the pre digital days, when everybody used film, some photographers considered ISO 400 to be high. I remember experimenting with a 400 ISO slide film known for its large grain (I rather liked the effect). If you were adventurous you’d go for an ISO 1000 or ISO 1600 film. Most photographers never touched films with such high ISOs!
Early digital cameras were little better. You had to think before using ISO settings like ISO 400, 800 and 1600.
But fast-forward to the present day and there are digital cameras with ISO settings as high as 102,400. Twenty years ago few photographers would have thought this would be possible.
The evolution of sensor technology makes it hard to define exactly what a high ISO is. For the sake of simplicity I define it as ISO 3200 or higher. But your definition may vary depending on which camera you use, how old it is and your tolerance for noise.
How important is the ISO setting?
ISO used to be important because it had a big affect on image quality. But nowadays image quality is better and ISO isn’t as important as it used to be. And it’s not as important, from a creative point of view, as aperture and shutter speed.
That’s because aperture and shutter speed both affect the look of your photo much more than ISO.
Aperture controls depth of field. If you need to stop down to get more of the subject in focus, that’s more important than ISO.
If you need a faster shutter speed to freeze movement (or prevent camera shake) then that’s also more important than ISO.
In other words, get the aperture and shutter speed right first, for your own creative and practical reasons. Then let the ISO go where it needs to. In low light scenarios, such as shooting outside at dusk, you’ll be using high ISOs, and that’s fine.
Learn to appreciate your camera’s high ISO settings. They let you make photos that would have been impossible in the past.
Test your camera’s high ISO settings
This is all about trusting your camera and understanding how it works. If you’re unsure about the effects of using high ISO on your photos, then you need to test your camera.
Go out at dusk and shoot some photos at your camera’s various high ISO settings. Go home and look at them on your computer. At what point does the noise become too much for you? How high are you happy to push the ISO?
This is a personal decision that nobody else can make for you. But be sure to read the tips below on minimizing noise at high ISO settings before you do your test.
For example, here’s a portrait I made in low light with an ISO of 25600.
It was an experiment, and I wasn’t expecting great results, but the test revealed three problems.
- Too much noise.
- The light wasn’t great.
- The camera struggled to focus accurately.
This simple test that took a few minutes showed me that I couldn’t get good results in these conditions at ISO 25600.
High ISO settings and your lens
The lens you’re using on your camera has a big influence on your ISO.
Let’s say you are going out at dusk to take some photos. You have two lenses to choose from – an 18-55mm kit lens with a maximum aperture of f5.6 at 55mm, and a 50mm f1.4 lens. Which one would you choose if you could only take one?
You might feel that you need the zoom, but the 50mm f1.4 lets in three stops more light at the widest aperture. This lets you use a lower ISO or faster shutter speed. Plus you can experiment with bokeh at the wider apertures.
Focal length is another consideration. If you’re using a long telephoto lens then you’ll need to use a faster shutter speed to prevent camera shake. This means using wider apertures or higher ISOs to compensate.
What about Image Stabilization / Vibration Reduction?
Many lenses (and some camera bodies) have some form of Image Stabilization (camera manufacturers have different names for this feature).
Image Stabilization lets you use slower shutter speeds (and in turn lower ISOs or smaller apertures) than would be otherwise possible.
But remember that Image Stabilization doesn’t prevent blur caused by subject movement. If you’re taking a photo of a walking person, for example, at 1/60 second then you’re going to get blur. You’ll need to use a faster shutter speed if you want to freeze that person’s movement.
How to minimize noise in your photos at high ISOs
There are two ways to minimize noise in your high ISO photos.
The first is to get your exposure correct. If you underexpose a photo and compensate by making it brighter when you develop it you’ll get more noise, especially in the shadows.
You’ll get a better result (i.e. less noise) shooting at ISO 6400 and getting a good exposure, then shooting at ISO 1600 or 3200, underexposing, then making the photo brighter.
Learn more: Exposure Lesson #6: Exposing to the Right
The second is to minimize the shadows and dark tones in your photo. This is a consideration not a rule. If you’re shooting at dusk (for example) then it’s natural to end up with shadows in your photo. Just bear in mind that noise shows up a lot more in the shadows than it does in the highlights when composing your photos.
Examples of high ISO use
Let’s finish this tutorial with some examples of where I’ve used high ISOs in particular photos, so you can see how it works in practice.
Inside dimly lit buildings
If you’re indoors and there’s not much light, and you don’t have the option to use a tripod, then you’ll need to hand hold your camera to make a photo. Image Stabilization can help, but you may also need to use a high ISO. I made the photos below in a dimly lit temple in China, and in a glassblower’s studio. Raising the ISO to 6400 enabled me to get the photos.
Making portraits at dusk
Making portraits at dusk, when there isn’t much ambient light, is a challenge. So why do it? The answer is that low light is often beautiful. I made the first portrait below (left) just after sunset. The afterglow of the setting sun lit the model’s face and gave it a red glow. You don’t get that quality of light at other times of the day.
In the second portrait (right) the lights in the background have come on, adding mood. I made the photo in the short period of time when the fading light balances with the artificial light sources. Again, that creates mood.
In both cases you need a high ISO and a wide aperture to get a good exposure.
If you use a low ISO to photograph the night sky the resulting long shutter speed turns stars into circular lines. That’s fine if it’s the effect that you’re after. But what if you want to capture the stars as points of light instead? In that case you need to use a high ISO and a wide aperture to limit the shutter speed to around 20 seconds.
Many concerts take place indoors or during the evening. If you’re lucky enough to be able to take photos without restriction then you’ll need to use a fast shutter speed to freeze any action combined with a high ISO. In both photos below I needed to use ISO 6400. The first photo is of a guitarist playing at an outdoor concert, the second of a little boy watching in the audience.
In murky lighting conditions outside
Depending on where you live there are times in autumn and winter when it’s dark and cloudy outside, even during the day. The situation is worse if you’re in a forest and there are trees blocking the light. I had to use ISO 3200 to make the photo below, and that was with an aperture of f2.
Light painting effects
If you’d like to experiment with painting with light techniques you’ll get the best results at dusk. It’s all about balancing the fading background light and whatever tool you are using for light painting. Even with a tripod and shutter speeds around two to four seconds you’ll need a high ISO to get a good result.
Travel photography at dusk
Dusk is an interesting time to make photos as the light is so moody. If you’re traveling, especially in warm or developing countries, it’s also a great time to be outside with your camera as so much life is lived on the streets. You’ll need a high ISO to get good results, especially if you stop down for more depth of field.
You don’t have to travel far from home to do this either. There are plenty of interesting subjects close to hand. I made the photo below a few blocks from my home.
Using a telephoto lens in low light
If you use a telephoto lens in low light then you’ll also need to use a high ISO to get a shutter speed fast enough to prevent camera shake. For the photo below I had to use ISO 1600 (a high ISO on the camera I had at the time) to get a shutter speed of 1/400 second that would guarantee me a camera shake free photo with my 50-150mm lens.
You may think that I could have used a slower shutter speed (like 1/200 second), but in practice with telephotos you usually need to increase the shutter speed by at least a stop to avoid camera shake.
If you’re shooting wildlife or sport you may have no other option than to use a telephoto lens. But if the situation allows another option is use a lens with a shorter focal length. That means you can use a slower shutter speed and keep the ISO lower (or use a smaller aperture).
The high ISO capabilities of digital cameras means you can now make photos that would have been impossible with film, so enjoy the freedom your camera gives you to make photos in these conditions. The examples I’ve given should give you some ideas and inspiration for photos you can make using high ISOs.
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