UNDERSTANDING ISO

photo of candles inside cages
Photo by Craig Adderley on Pexels.com
ANOTHER ARTICLE ON: “SOMETHING YOU CAN’T DO WITH A CELL PHONE”

Too often in today’s world, it seems that people are thinking that cell phone photography is getting close to everything a regular SLR or DSLR, or even a mirrorless camera can do.

This article will dispel that myth so you can see that cell phone photography is still far away from doing what a good camera can do.

WHAT IS ISO?

ISO refers to your camera’s sensitivity to light. The higher the ISO, the more sensitive your camera sensor becomes, and the brighter your photos appear.

ISO is measured in numbers. Here are a few standard ISO values: 100, 200, 400, 800, 1600, 3200.

That said, pretty much every camera offers intermediate ISO values (for instance, ISO 125 and ISO 160 between ISO 100 and ISO 200). And most cameras these days include additional ISOs on the high end of the range, such as ISO 6400, ISO 12800, ISO 25600, and beyond.

WHAT DOES ISO STAND FOR?

ISO is the acronym used by the “International Standards Organization”. This is where the ISO came up with it’s standard across the world.

For the purposes of photography, the name isn’t important. Just think of ISO as your camera’s sensitivity to light, and you’ll do just fine!

ISO AND YOUR EXPOSURE SETTINGS:

By increasing the ISO in your camera, you are making the light meter more sensitive to light. It would allow you to shoot in different types of light, even when light is not good.

person standing beside waterfalls
Photo by Jeremy Bishop on Pexels.com

The first number that you would use in your ISO setting is usually 100, and is the basis for shooting in good light, such as sun, and bright light. You would then be setting your shutter speed and aperture according to what your desired effect is.

THE HIGHER THE ISO NUMBER, THE BETTER YOUR RESULTS WILL BE IN LOWER LIGHT:

Now if we go from 100 ISO to say 800 ISO, you will now have some control over what is normally not scene in the darker shadows of your photo. Like this:

an underexposed image of a room
A Picture shot at 100 ISO.
a well-exposed image of a room
Maybe shooting the same photo at 800ISO will give you a great exposure inside where it once was dark.

Both the above pictures have something to be aware of. If shooting at 100 ISO, the photo is usually perfect if shooting outside. Look at the exposure of the outside through the window, with the first picture.

Now, looking at the second exposure, for sure it seems like it’s a better picture. But, now the outside is so washed out, the picture really seems kind of useless, because it is now over exposed. Although it looks perfect inside, where the lighting isn’t so good. So, which one do you like? Either one will work, it just depends on what you want in your photo.

HOW DOES YOUR ISO WORK WITH YOUR SHUTTER SPEED AND APERTURE?

To get the perfect exposure, it is all a combination of ISO, the proper shutter speed, and the best aperture setting. All 3 of these are important. Let’s look at why you would change your ISO setting when you have the perfect light.

A QUICK LESSON ON SHUTTER SPEEDS:

I know this is a lesson on ISO settings, but, let’s look at the other settings it has to work with: The first being the shutter speed.

If you set your camera at ISO 100, the perfect exposure outside will probably be: 1/125 second, and the aperture or F Stop will be F16. Perfect exposure. If you will recall, the faster the shutter speed, you can now stop action:

timelapse photography of green and white racing vehicle on lane
Photo by Chris Peeters on Pexels.com

If you want to stop action, then your shutter speed will need to be close to 1/1000 second. To get the proper picture then, the easiest thing to do is to raise your ISO from 100 to 800 ISO to get the proper exposure. (That is as long as the aperture stays the same).

You see that changing your shutter speed, you will need to change your ISO to keep things in proper exposure.

CHANGING YOUR APERTURE WILL ALSO GIVE YOU THE NEED TO CHANGE YOUR ISO:

pink rose
Photo by Jonas Kakaroto on Pexels.com

Now let’s see what can happen if you want to change your aperture setting to get a shallow depth of field, like the above photo.

If you change your setting on your aperture to F2.8, there may be the need to change your ISO, but it can’t go lower than 100, right? (Most newer cameras will only go as low as ISO 100). So, the only thing you can do here again, is to change your shutter speed, to match the ISO of 100. Changing it to F2.8 would mean you would need to change your shutter speed to 1/2000 second. That will allow you to get the exposure you need.

DIFFERENT SCENARIOS YOU WOULD USE TO CHANGE YOUR ISO SETTINGS:

* WHEN TO RAISE YOUR ISO:
  • You’re shooting at an indoor sports event, especially if your subject is moving fast
  • You’re shooting a landscape without a tripod and you need a deep depth of field
  • You’re shooting a landscape at night (or doing astrophotography) and you need a reasonable shutter speed to freeze the stars
  • You’re photographing portraits in a dark room or in the evening/night
  • You’re shooting an event indoors with limited window light (such as a party)
  • You’re photographing a dark concert
  • You’re photographing an art gallery, a church, or a building interior (you might also consider using a tripod, but this is against the rules in a lot of spaces)
  • You’re photographing wildlife in the early morning or evening (especially if you need a fast shutter speed)
  • You’re photographing fast-moving subjects and you need an ultra-fast shutter speed
* WHEN TO LOWER YOUR ISO:
  • You’re shooting motionless landscapes and your camera is mounted on a tripod
  • You’re photographing portraits in good light
  • You’re photographing an event, and you have plenty of window light or you’re using flash
  • You’re photographing products with a powerful artificial lighting setup
portrait of a handsome man with muscular body
Photo by emre keshavarz on Pexels.com

CONCLUSION :

ISO and shutter speeds and aperture settings all work together. It just depends on what you want to achieve in your photo, that will be what you need to set for ISO, Shutter speed, and F Stops. We will go into why you would change your shutter speeds and the effects you can get with changing it. And then we will get into why you would change your aperture setting as well. Keep with me…….

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