[Photography] How to Avoid and Reduce Noise in Your Photos (2021 Guide)

The post How to Avoid and Reduce Noise in Your Photos (2021 Guide) appeared first on Digital Photography School. It was authored by Barry J Brady.

We’ve all seen it in our images: that uneven grainy look that makes our images unappealing.

But how can you avoid noise? And, in cases where it’s unavoidable, how do you reduce noise in photos?

In this article, I’m going to share plenty of tips and tricks for both preventing and removing noise. Specifically, I’ll share:

• Why you’re actually dealing with noise in the first place
• Five simple ways to stop noise from ever appearing in your images
• A noise reduction workflow you can use to reduce noise in Lightroom and Adobe Camera Raw

Sound good? Let’s dive right in, starting with the important first question:

What is noise?

Generally speaking, noise is defined as aberrant pixels. In other words, noise is made up of pixels not correctly representing the color or exposure of the scene.

Why does noise happen?

Noise is introduced when you shoot a long-exposure image or use a high ISO setting on your camera.

(What counts as a high ISO setting? That depends on your camera model, but these days, most cameras start getting noisy around ISO 1600 or 3200.)

Does that mean you should never do long exposures or go over ISO 100?

No! There are times you may need – or even want – to use long exposures or raise the ISO. Landscape photographers, event photographers, and wildlife photographers shoot in low light all the time, which requires long exposures and/or a high ISO.

At the same time, there are simple ways to avoid too much noise in your photos, even when using the above techniques, which I’ll discuss in the next section:

Reducing noise in your images can make a huge difference to the overall quality.

5 ways to reduce noise in-camera

Below, I share the five methods for minimizing noise while out shooting.

Not every method will apply for every situation, which is why it pays to be familiar with all of them – and to carefully choose the right method for your particular shot.

1. Shoot at lower ISO settings

Yes, we’re starting with the most obvious method. But photographers often push their ISO too high, too fast, leading to bad image quality.

Now, if your camera is three years old or newer, the ISO functionality will be great. You shouldn’t see too much noise creeping into your images, even up to ISO 3200. However, there might still be some noise at the higher ISO numbers, such as ISO 6400, ISO 12800, and beyond.

So don’t raise your ISO with abandon. Instead, be aware of your exposure, and recognize that shooting at a high ISO will produce more noise in your images. Boost your ISO if necessary, but consider other options before dialing in ISO 12800.

Here are a few items to think about before increasing the ISO:

• Open your aperture to its widest setting (e.g., f/2.8)
• If you are shooting in low light, use a tripod and drop your shutter speed
• If you are shooting a smaller subject (e.g., a person), use a flash

Each of these strategies will help you get a nice, bright exposure – without unnecessarily raising the ISO.

Of course, if your shots are still turning out dark, then you will need to push the ISO up higher. I’d recommend doing some test shots to find out your camera’s ISO capabilities and at what point the ISO settings start to really degrade image quality.

For many years, I shot on a Nikon D80, and I knew that anything above ISO 500 was really difficult to use. Noise at ISO 640 and beyond became difficult to remove. And if I was able to successfully remove it, the whole image looked like a watercolor painting thanks to the noise reduction process. So I worked within my constraints.

2. Shoot in RAW format

Does the idea of shooting in RAW intimidate you? It shouldn’t! RAW is a great way to get the best out of your images, so be sure to use it.

You don’t have to shoot RAW all the time. But when you notice that the light is becoming a little too dark, switch over to RAW.

Why is this so important?

JPEGs come with compression – a process during which noise becomes baked into your images. So removing noise in post-production becomes really tough (as does increasing exposure, which is often important in high-ISO situations).

3. Expose correctly from the start

Boosting a too-dark exposure will reveal noise – which is why it’s essential that you get your exposures right from the very beginning.

When out shooting, I highly recommend checking your camera’s LCD – including the histogram – to make sure you’ve nailed the exposure.

And don’t be afraid to take several shots at different exposures, especially if you’re dealing with a tricky scene; better to be safe than sorry!

Also, the higher your ISO, the more unforgiving the file. In other words: If you’re using a high ISO, you had better get the exposure right, because boosting an underexposed high-ISO image will result in a noisy mess.

(Of course, don’t overexpose, either. While overexposure won’t cause problems with noise, it will obliterate detail, which is never a good thing.)

4. Be careful when doing long exposures

Long exposures produce some of the most dramatic images.

But if the exposure is too long, the camera sensor may heat up, causing unwanted noise.

Don’t let this stop you from doing long exposures – if you love long exposures, then do long exposures – just be aware of how your camera handles the long exposure time.

In fact, you might consider shooting a series of long exposures, then checking each file on your computer for noise.

Then, once you’ve determined your camera’s limitations, make sure you don’t set your shutter speed for longer than your camera can handle.

The key point here is to know the limits of your gear and to shoot within those limits. You’ll end up with great images and have an easy time when editing.

Long exposure images can increase noise in a scene.

5. Use in-camera noise reduction

Most cameras offer a function called Long Exposure Noise Reduction, and if you’re doing long exposures, it’s a good idea to turn it on.

Why?

Well, as discussed above, long exposure photos are especially prone to noise. A long exposure noise reduction option is designed to counteract this issue – by taking a second shot after the first, then using the noise profile of the second image to subtract noise from the first.

Long exposure noise reduction comes with a serious drawback, though: it takes time, usually as long as the original exposure. So if you use a 30-second shutter speed, the camera will take an additional 30 seconds to get rid of the noise. And if you shoot for an hour, you’ll need another hour to reduce the noise, which is an annoyingly long time to wait!

So yes, it may be impractical if you are doing 10-minute shots. But for medium-length long exposures, it’s often worth doing.

(And if you do have the timed, do it on the very long exposures too, as it can dramatically improve the image quality.)

Use in-camera noise reduction for long exposures!

Reducing noise in Lightroom or Adobe Camera Raw

Even with the best techniques, you’ll still end up with noise in your photos – at least on occasion.

Which is where post-processing noise reduction techniques come in handy!

Here’s my recommended workflow using Lightroom Classic or Adobe Camera Raw (but note that you’ll be able to use very similar methods in other programs):

Step 1: Open your image and view at 100 percent

Start by opening your image in Lightroom or Photoshop.

Note that RAW images opened in Photoshop will first go through Adobe Camera Raw, which is what you want. Also note that the controls in Adobe Camera Raw and in Lightroom are identical, so while the photos below are taken from ACR, the instructions are equally applicable to Lightroom users.

The noise reduction sliders in Adobe Camera Raw are identical in Lightroom.

I recommend viewing your image full screen, then zooming into 100 percent. The goal is to look for noise; after all, not all images require noise reduction.

Adobe Camera Raw has some powerful noise reduction tools.

Step 2: Adjust the Luminance slider

The Luminance slider reduces luminance noise (i.e., noise resulting from over- or underexposed pixels).

And many, many high-ISO images suffer from excessive luminance noise.

So zoom in to 100 percent, then boost the Luminance slider until the noise starts to disappear.

Don’t go too far, however,

Step 3: Fine-tune your result with the Luminance Detail and Luminance Contrast sliders

The Luminance Detail and Luminance Contrast sliders control the amount of detail and contrast preserved in your photos following luminance noise reduction.

You see, noise reduction smooths out noisy pixels, which automatically reduces detail and contrast. But by boosting these sliders, you’ll retain detail and contrast.

As you’d expect, the sliders do come with a drawback:

When you increase the values, you decrease the strength of the noise reduction. So while you’ll end up with a sharper image, you’ll also see more noise.

Step 4: Adjust the Color slider

The Color slider reduces color noise – which is the second type of noise you’ll find in your photos (often in the underexposed shadow areas).

So boost the Color noise slider, and zoom into 100 percent to see its effects.

Step 5: Fine-tune your result with the Color Detail and Color Smoothness sliders

As with luminance noise reduction (above), you can further adjust your image with the Color Detail and Color Smoothness sliders.

Want more detail in your photo? Boost the Color Detail slider. Higher values will protect thin, detailed color edges, but can also result in color speckles. Lower values remove color speckles but can result in color bleeding.

Want to keep colors nice and smooth? Boost the Color Smoothness slider.

And you’re done!

A final note on noise reduction

While I wish I could give you standard, one-size-fits-all settings for noise reduction, it just doesn’t work that way. Every image is different, so you’ll need to slide each adjustment around until you get your desired result.

I tend to increase Luminance and Color to about 50, then work from there. I slide each option up and down, carefully watching how it affects the image while zoomed in to 100 percent.

Then, after each adjustment, I zoom out to see the effect it has on the overall image. And if I’m happy with an adjustment, I move onto the next slider.

Is the process a little tedious? Sure. But if done properly, you’ll eliminate most of the unsightly noise in just about any image.

Practice is also important here, so try this on as many images as you can. Pretty soon, you’ll be able to predict the effect of each change.

How to avoid and reduce noise in your photos: conclusion

Now that you’ve finished this article, you know that avoiding and reducing noise shouldn’t be too complicated. Just follow the steps I’ve given, and your images will turn out great.

Now over to you:

Do you have any other tips for noise reduction and removal? Share your thoughts in the comments below!

The post How to Avoid and Reduce Noise in Your Photos (2021 Guide) appeared first on Digital Photography School. It was authored by Barry J Brady.

it's from Digital Photography School https://ift.tt/3x2DGcY
via Barry J Brady