ISO Image


Thank you for visiting my blog! This is the first entry of my Photography 101 series. In Photography 101, we will learn how to use our cameras. What you need is a DSLR, your camera’s manual, and a can-do attitude. This series is for the beginner. I am also working on Photography 201, which is learning about light. Check back often for updates.

First thing is first, take your camera off of Auto. No, really… do it now. Change your camera from Auto to Manual. It’s not so scary once it’s there. You there? Good! Now that you are on Manual, go read your camera’s manual about the settings of ISO, Shutter Speed, and Aperture (this may be referenced as F-Stop). Go ahead, I’ll wait. 🙂

Do you understand how to change your ISO, Shutter Speed, and Aperture? Great! You don’t need to understand what they are yet, just how to change them on your camera. Okay. Now, change your settings to the following:

  • ISO:100
  • Shutter Speed: 1/125
  • Aperture: 5.6

We are going to experiment with only ISO today. ISO is basically how sensitive your camera acts towards light. Here is a diagram that explains the affects ISO has on an image.

ISO Kristen D. Photography

There is a compromise on each end of the ISO scale. Low ISO gives you a clearer photograph, giving your more details. However, if you aren’t in a bright room or outside on a sunny day, the low end will give you underexposed photographs. On the other hand, high ISO will brighten your image, but will add noise (also known as grain) in your photo. Here is an example using my son’s train set.

ISO 100
ISO 100

ISO 6400

ISO 6400

I did adjust the shutter speed to keep the exposure the same in the above photos. Do you notice how the ISO 100 image has no grain? Now, look at the ISO 6400 image. Do you notice the added noise? The noise (or grain) comes from your camera amplifying the light available.

Let us look at how ISO affects exposure (how light or dark your image is, in brief). ISO usually begins at 100 and then doubles, with 1/3 stops between. In the following photographs, I kept the Shutter Speed at 1/125 and Aperture at 5.6. I only changed the ISO beginning at 100 and going to 6400.

ISO 100

ISO (1 of 9)

ISO 200
ISO (2 of 9)

ISO 400
ISO (3 of 9)

ISO 800
ISO (4 of 9)

ISO 1600
ISO (5 of 9)

ISO 3200
ISO (6 of 9)

ISO 6400
ISO (7 of 9)

Now it is time for you to experiment. Take your camera and photograph something in the room. It doesn’t have to be pretty, I just used my son’s train set. Start from ISO 100 and take the photo. Repeat the process at ISO 200, 400, 800, 1600, 3200, and 6400. I’ll wait. 🙂 Now, review your photos. Which ISO setting do you like the best for your photograph? I like ISO 800 for mine. Your’s could be very different, because the room in which you took your photos will have different lighting than mine.

Now for the second experiment. Is it sunny outside? If it is, then go outside and repeat the last experiment. I’ll be here when you get back. What did you notice about your photos? Did your photo start getting overexposed (overly bright) more quickly than your indoor photos? Most likely they did. That is because on a sunny day, there is much more light. Remember that ISO amplifies the light you have available. The more light you have, the more overexposed your image will be at high ISO levels.

So a general rule of thumb is to use lower ISO in bright situations, such as outside on a sunny day. Use higher ISO in darker situations, such as school plays.

Now it is homework time! Here is a list of photographs I want you to take and find the ISO you like for each photo.

  1. A flower on a bright, sunny day.
  2. A glass of water on your kitchen counter.
  3. A landscape on an overcast day.
  4. A candle in a dark room. (Safety first! If you are a minor, ask your parents for permission before lighting a candle. Take steps to ensure you don’t burn down your house.)

You can also experiment on your own. Find the ISO you like for each situation. Soon you will be able to say, “Oh! I need ISO 400 for this situation!”

Thank you for reading! Please post your favorite pictures in the comments below! Stay tuned for more in the Photography 101 series! – Kristen

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: