Do you know what nirvana looks like to a digital camera photographer? High ISO photos with low noise. Until recently, that's been almost impossible - as you increase the ISO further, more and more noise appears in your image. However, cameras have started to arrive in the consumer market that sport this wonderful feature. And as I'll explain, being able to shoot with low noise at a high ISO will dramatically increase the options available to you as a photographer.
[ Top image Tea & Sympathy by Flickr user Sean Molin Photography]
I often begin these articles with some anecdote about what photographers had to go through back in the olden-days of film, you know, barefoot in the snow and all that. You may be pleased to hear that I won't be doing any such thing this time. In fact, I will instead begin this article with an anecdote about what photographers had to go through in the olden-days of digital.
Digital photography has had some growing pains, starting with those 640 x 480 pixel cameras that took pictures that didn't really even look nice when you printed them at 2 x 3. That's right, in those days megapixels were for chumps, because, you know, they didn't even have 1 megapixel. Digital cameras got better, but it took a while before the technology got to the point where it was on par with what film cameras could do. It took even longer before digital cameras surpassed film cameras, and now in many ways they finally have.
A prime example of this is ISO. Film cameras and digital cameras have always had a roughly similar problems when shooting at high ISOs, but digital cameras had it a little worse. To understand why you need to know the difference between "grain" and "noise".
Grain vs. Noise
"Grain" refers to the visible structure of the film itself. Faster ISO films are made from larger particles than slower ISO films, which results in visible "grain" on an image. Film grain has a kind of sandy appearance, and the size of those grains of "sand" depends on how fast the film is. A 1600 ISO film, for example, will have larger grains than an 800 ISO film but smaller grains than a 3200 ISO film. Film grain is also color-neutral.
Digital noise, on the other hand, though similar to grain is another animal. Digital noise is always pixel-sized, regardless of how fast your ISO. It is also not color-neutral, so you will see it in the color channels of your image, especially in the blue channel. Depending on the age/quality of your camera, noise may also manifest as "banding," which are long streaks of noise that look particularly awful.
This is film grain, which has a sandy appearance. Film grain gets larger as ISO increases, while digital noise is always the size of a pixel.waiting for her entrance by Flickr user clickykbd
Why you want to avoid noise
Now, let me preface this by saying that noise isn't always a bad thing. Noise can add an artistic quality to your images—it can make them look gritty, which is great for photojournalistic-type images or shots that you want to have a darker emotional impact. It tends to work best, though, in images that are converted to black and white, because all that colorful noise can be distracting in a color image. But most of the time, we photographers want to avoid noise. Noise can interfere with the clarity of your image, it can be distracting, and it can also have a negative impact on the quality of your photos, especially those images where fine detail is important. You can remove it in post-processing, but because noise-reduction tends to also reduce detail, ideally you want to reduce that noise in-camera instead.
The noise in this image interferes with the clarity of what would otherwise be a sharp picture of a falling drop of water.Water droplet by Flickr user Dav1dfv
Five advantages to using a low-noise camera
When cameras capable of low noise at high ISOs first came out, they were pricey. Fortunately, technology in this area has really grown in the last few years, and now you can get a low noise, high ISO camera for considerably less. If you've been wondering whether you should upgrade your older digital camera to one of these low-noise models, the answer is yes! If you need a few reasons why, here they are:
The first and most obvious reason why you would want to buy a low-noise, high ISO camera is because you will reduce or eliminate noise at ISOs where noise used to be a very obvious problem. In older digital cameras, noise was very apparent at ISOs as slow as 1600 or 800, but today you can buy cameras that take noise-free pictures at ISOs of 6400 or higher.
What does this mean in practice? You can now go out in very low light conditions and capture photos that don't require noise reduction. Although some cameras will actually do noise reduction for you, this can be a slow process. You'll get some loss of detail and you'll also be able to take fewer pictures while you're waiting for the noise reduction to complete.
Give Me a Hug! by Flickr user Chris Smith/Out of Chicago
Kiss your onboard flash goodbye
Have you ever just given in and popped up that flash even though you knew you weren't going to get a great picture? Everyone bends to popup flash temptation occasionally, because sometimes we're surprised by just how low the light is and it's impossible to get any sort of shot at all without adding flash—unless we use one of those super-noisy high ISOs instead. But if you trade your old camera in on a low-noise, high ISO model, you can turn your ISO way in low light situations. This makes it possible to capture clear shots you otherwise would have lit with your flash.
Alli | Focus by Flickr user Sean Molin Photography
Avoid camera shake and motion blur
There are plenty of situations where you want to shoot moving subjects in low light and you don't have a tripod. Before those low-noise high ISOs were available, this meant you had to choose between a noisy photo and one with motion blur, because it just wasn't possible to shoot at a higher shutter speed without compromising image quality. With a newer camera, you can shoot at ISO 6400 or higher, use a fast shutter speed to freeze the action and you don't have to worry about camera shake because you'll be able to hand hold your camera.
Are We Dancer? by Flickr user JeremyHall
More depth of field in low light
It's challenging enough to focus in low light without having to worry that your subject is going to move an inch or two and mess everything up. At those very wide apertures, you don't get much depth of field, which means there's also not a lot of room for error. When you use a higher ISO, you can use a smaller aperture. The benefit to this, of course, is that now instead of that razor thin focal plane you have the flexibility to change aperture and increase your depth of field. This also increases your margin of error when it comes to focusing in low light.
07-25-2010 Provo River Falls Night 21mm_Panorama1.jpg by Flickr user ClintonMelander
Maintain the Mood
One thing that can happen whenever you add light to a scene—and this goes for popup flash as well as external flash—is that you end up changing the mood of the scene dramatically. Imagine trying to photograph your child blowing out his birthday candles; do you want an image of him sitting there in the dim light with his face beautifully illuminated by the birthday candles, or would you rather fill the room with artificial light so that the candles are barely a footnote? I hope your answer is the former. When you have a camera that can capture quality images at high ISOs, you don't need to wreck the light (and the mood) anymore.
fuji xpro 1 + 35mm 1.4 by Flickr user marcgelinas
It used to be that the above suggestions were leading you towards buying a camera that most people can't afford, but we're living in an amazing time. Modern digital cameras—and not just DSLRs, either—have great high ISO capabilities, and that's something you should take advantage of. If you haven't upgraded yet, there's never been a better time.
Most people think this post is Interesting. What do you think?