Nick Carver Photography Blog

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Common Misconceptions: High ISO Noise

The Misconception:

Digital noise caused by a high ISO setting will ruin the image.

Why This is Wrong:
Alright here’s the deal, high ISO noise is not nearly as big a problem as people make it out to be. True, higher ISO settings result in more digital noise. No doubt about that. But it is very unlikely to ruin your shots. The final presentation size must be taken in to account when determining whether or not digital noise is something to be worried about. Sure, the maximum ISO on your camera will exhibit quite a bit of noise when you look at the image magnified 100% on the computer. But that’s not an accurate representation of the image. How often do you print that big? And even if you do print that big, how often will you view that print from just inches away like you do on your computer?

It’s tempting to judge photos at full magnification on the computer, but resist the urge. Everything looks bad that big. Don’t believe me? Take a headshot of yourself then see how you like critiquing the image at that high of a magnification (look at those pores!).

This is why when I analyze film negatives on a light table, I don’t use a 10x magnification loupe even though they do exist. I use 4x for most viewing and an 8x only if I want to really critique a negative. If the loupe magnifies the image too much, the negatives just start to look soft and grainy. And it wouldn’t be a realistic critique of the image because it’s not like I’ll be blowing up the image to those magnifications, and even if I do, people won’t view it from inches away.

High ISO Noise

Below are 100% magnification crops from the original 12-megapixel image (above)
On the left is ISO 100 on my first-generation Canon EOS 5D,
on the right is ISO 3200 (the max ISO).

The noise is, of course, noticeable in these magnified views, but how big is the image
really going to be viewed? This noise won't be noticeable except for at very large
print sizes. Plus, newer cameras will have much better high ISO performance
than my out-dated 5D.

High ISO Noise

The Truth:
Unless you print really big, high ISO noise ain’t going to ruin your shot. And if you do print big, it still won’t be as big of an issue as you think. The bigger the print, the further away you view it from. And besides, most people’s pictures end up on Facebook barely bigger than a greeting card. Noise won’t show up on an image that small. You may see it because you know it's there when it's blown up, but others won’t see it.

Yes, you should use the lowest ISO you can in any given situation just so you don’t have needless image noise, but sometimes you need an ultra-high ISO to get the shot. If you do, don’t worry about the noise. Know that it’ll be there, but don’t let it prevent you from taking the shot. Like I tell my students, “better to have the image with some noise than no image at all.”

My Thoughts and Rants:
As far as I’m concerned, high ISO noise is basically a non-issue today. Every new generation of camera is getting better and better at reducing digital noise. Today’s cameras are so good at high ISOs that it’s practically not even worth talking about. Plus, no one prints anymore (which is a tragedy in its own right). It’s all Facebook, Flickr, email, slideshows, photo books, iPhones...all great ways to share photos, but they simply don’t show the images blown up very big. So why are we even talking about noise?

And remember that no one else will ever notice the digital noise in your images. Your family, friends, clients - they won’t see it. Other photographers will, but who wants to impress them anyway? Other photographers are un-impress-able.

There are a thousand things that will ruin your photos. Digital noise is number 999. Good technique, good light, good composition, good subjects...Focus on that.