ISO Ranges and Performance

DM FB Blog Preview Sizing 1200630

Your ISO setting is important to understand and set correctly to ensure your images are of high quality. Along with shutter speed and aperture, it is one of the main functions to comprehend.

What Is ISO?

To explain it simply, ISO allows you to lighten or darken your image. The lowest ISO of 100 is the darkest, and your photo will get lighter as you increase the ISO (without changing the other settings). In bright sunlight, you might use a low ISO of 100 or 200. In a dark setting indoors, you might push your ISO to 800 or more to allow more light. Adjusting your ISO can help you shoot in low light and have more flexibility with aperture and shutter speeds. 

The downside is the higher your ISO, the more grain you might see. Grain or noise can be reduced in the editing process. If you are printing the image at a small size, you might not even notice it much. You can smooth the image in post-production to make it look less grainy. A grainy image might even be desirable. Often it can look moody or artistic, especially with black and white imagery. 

The more you enlarge an image, the more obvious noise or smoothing techniques are. So you should always keep your ISO as low as possible, only increasing it when you really need to. If you can lighten the image by adjusting your shutter speed and/or aperture, it is preferable.

ISO Settings

  • ISO 100 (low ISO)
  • ISO 200
  • ISO 400
  • ISO 800
  • ISO 1600
  • ISO 3200
  • ISO 6400 (high ISO)

As you double your ISO speed, you double the brightness of your photo. So, if you take a photo of a cat at ISO 400, it will be twice as bright as the same image taken at ISO 200.

The Wonders Of High ISO Settings

It is amazing what digital cameras can capture at high ISO settings. These days, technology is advancing quickly and the noise you see at ISO 6400 is much less than it was a decade ago, for example. 

When you don't want to use flash or aren't allowed to use flash (such as in a church or temple), using your ISO setting to light up an image is a lifesaver. If you are taking photos for fun and don't plan to enlarge them, shooting at ISO 3200 or 6400 can be creatively satisfying. If you use a tripod so you can have a slower shutter speed, your ISO settings can push the boundaries of your photography even more. For shooting interiors, this can be very useful.

A stunning sunset captured at a high ISO. You can see the sky is grainy, but beautiful all the same!

When Do You Need High or Low ISO?

If you are shooting stock photography, a low ISO is essential. Images with too much noise will be rejected if they are not sharp when viewed at 100%. If you are shooting for clients who might enlarge their photos, you should also try to control the ISO. A bride and groom, for example, might be disappointed if they printed their favorite image at a large size and it looked grainy. So basically, a high ISO can compromise the quality of your image. Even if you are aiming for a grainy look, you can shoot at a low ISO and add grain during editing. This gives you more options to manipulate your photo later. 

Many cameras have an auto ISO setting which lets your camera select the setting it reads as based on the lighting situation. We recommend always setting your ISO setting manually so you can have full control over the quality of your image. 

Even if the light is good, a higher ISO setting can help you achieve the results you want. If you need a really fast shutter speed to photograph a fast-moving subject, a higher ISO might help you freeze the motion. A sports photographer might use a high ISO combined with a fast shutter speed to capture a runner. A wildlife photographer might do the same to get a sharp image of a cheetah running across a field.

If you are shooting indoors without a flash and want to ensure capturing an important moment at an event, you might push your ISO setting higher as a safeguard. This would be especially important if your subjects were moving fast, such as a bride and groom entering a reception or a dancer coming onto stage for a finale performance. 

When you know how to use your ISO settings to your advantage, they can be very powerful. In some situations getting an image using high ISO, even if it is super grainy, is better than getting no image at all (or a very underexposed image that is hard to save). What if you run into Beyonce at the park on a cloudy overcast day? Knowing how to use your ISO could be vital in that amazing moment. We often see paparazzi images taken in terrible light. Even those grainy images of famous people can be very valuable. Or a parent might capture the first steps taken late at night in the dimly lit kitchen. Those moments can have great value, sentimental or financial, and your high ISO might be what makes it possible. 


Look closely and you can see a big number on the side of the film canisters. That is the ISO number.

Fun Facts

  1. ISO stands for International Organization for Standardization. But it doesn't actually refer to the organization. 
  2. In the “old days,” ISO referenced the sensitivity of film and how much light it could capture. High ISO film could capture images in low light and low ISO film was best used in well-lit situations. Isn't it amazing when you think about how much flexibility we get with digital cameras? These digital days ISO references the sensitivity of your camera's sensor.
  3. It is better to increase your ISO before taking the shot than lightening the image during editing. The quality will be higher. 
  4. Most digital cameras have ISO 100 as the lowest setting, also known as base ISO. Some older digital cameras start at ISO 200.

Now you understand what ISO is and how it works, you can use it to improve the quality of your photography. Experiment with different settings in all kinds of light and find out what you and your camera equipment are capable of. We think you will be impressed with the results.


11 thoughts on “ISO Ranges and Performance”

  1. Thank you for the information. I am trying to learn as much as possible about shooting in different light. This was very helpful and appreciated.

  2. Charmien Dexter

    thank you, that was very easy to understand and I look forward to experimenting and improving my shots.

  3. Thanks for the info, and this brought about a question; I heard another photographer friend mention the term ISO Invariance and the difference between simulated and real ISO in your camera. It really confused me and I do not think he really understood it either since he could not explain it very good. It seems very technical and differs with every camera.
    So is this something that I should read more about and get a good handle on, or something that is just out there and not worth the worry?

    1. David Molnar - Your Photography Mentor

      David, great questions! There is plenty out there to research on the topic. Some articles are going to explain it better than others. With technology being what it is, I tend to worry about it less than I used to. I think if you’re a new photographer, don’t worry so much about this right now. Pay attention to getting your settings right in your camera and things will fall into place and make for a great photograph. Again, there is enough information out there that you can research it, if you’d like. Good luck!

  4. Frances Schliminger

    Thank you for the great article. I am a beginner and read your book, purchased your online course and purchased a canon RP, with additional lenses and not the ones that came with the camera because I want it good lenses. Looking forward to finding time to get started and try it out. Been taking a lot of notes as
    I read your book and reviewed the online course.

Leave a Comment

Your email address will not be published. Required fields are marked *

Referral Link Copied!

Send it to your friends via text, email, or social media to invite them to TPM!

Select Your Camera
Please choose a camera for a personalized version of Master Your Camera.
Send this to a friend