A Beginner's Guide to Effectively Using ISO for Better Photos

ISO is one of the three fundamental exposure parameters and something you need to have mastered to take successful photos. If you are new to photography and still working on learning the basics, this great video tutorial will show you everything you need to know about ISO.

Coming to you from Photo Genius, this excellent video tutorial will show you everything you need to know about working with ISO. If you are still learning the basics, you can generally think of ISO as your sensor's sensitivity to light — the higher the ISO, the less light you need to make an exposure. The tradeoff, however, is increased noise and decreased dynamic range, thus the need to balance your ISO settings with the other exposure parameters. One thing to remember, however, is that it is always preferable to have a sharp photo with noise than a blurry photo without noise. You can always take steps to reduce the noise in post-processing a bit, but once a photo is blurry because you used too slow of a shutter speed for either your subject's motion or to prevent camera shake, there is little that can be done to save it. Check out the video above for the full rundown.

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Fred Larsen-Dowuona's picture

Nikon wide angle lenses

Károly Zieber's picture

It still baffles me to read things like "ISO is one of the three fundamental exposure parameters" on a professional site like FS in 2021. No, there is no such thing as exposure triangle. Exposure depends on illumination and exposure settings (only f-stop and shutter speed). ISO has to do with image lightness. It has nothing to do with sensor sensitivity, as sensor sensitivity to light is a structural constant. After setting the required f-stop and shutter speed for for your photography needs, ISO is a given. Don't do it backwards.

Black Z Eddie .'s picture

That’s because ISO is one of the three fundamental exposure parameters.

You are partially correct in saying you would set the required f-stop and shutter speed, ISO is a given. I say partially because this could apply to in a low light scenario. However, if you ever shoot outdoors in bright light (yes, people do do that), you would (should) know one of the first things you set is ISO, f-stop (or f-stop then ISO), then shutter speed.

Károly Zieber's picture

"That’s because ISO is one of the three fundamental exposure parameters." - that is simply not true. Exposure settings consists of the f-stop and shutter speed. Number of photons reaching the sensor/film area through the aperture under time unit. That is it.

In bright light with fixed exposure settings, ISO will be as low as possible, no need for setting, just as previously. If you want to underexpose in this situation, depending on what program you use (M, A, S), you can choose higher shutter speed, smaller aperture, ND filter, exposure correction (which can do any, depending on the program setting) or if not reaching lower limit because of the algorithm is trying to reach an image lightness it thinks adequate - ISO. That is it. Why would you choose ISO in the first place, if it has nothing to do with exposure, rather than image lightness? If you need a certain shutter speed and aperture for a purpose, ISO is the last. Amount of motion and depth of field for your purposes comes first, ISO is a given. Unless you you need a different image lightness, but that is not exposure.

ISO is not - of all the things it is not - sensitivity in digital technology.

One more thing: the latest update to the ISO standard makes it explicit that it does not apply to raw files.

Good read: https://www.dpreview.com/articles/9698391814/the-ins-and-outs-of-iso-wha...

Black Z Eddie .'s picture

I think you (probably based off that article) are over complicating things one thousand fold. Almost Illuminati TL;DR like. :)

Bottom line, the ISO setting isn’t going to set itself. Either you do it or the camera does it (auto ISO). Therefore, it’s one of the three settings on the camera to get the exposure you want. You can call it "lightness" (LOL) if you want. But, I think most of us will continue to refer to it as "exposure".

Károly Zieber's picture

Why the ignorance...nice. Keep on spreading inaccuracy and showing lack of understanding basic principles in photography. FS should be more, than just posting unreviewed, unverified and inaccurate videos. Brent Daniel's articles is the way to go.

Good read again from Richard Butler for those who want to hear something useful: https://www.dpreview.com/articles/8924544559/you-probably-don-t-know-wha...