Now that you have learned about the first two and most important parts of the exposure triangle we can talk about ISO. Or sensitivity. This is a very brief one because I don’t feel like it doesn’t call for a deep explanation. I have gotten this far without really getting into the deep end of ISO. So that’s why I don’t think it’s important. But it might be who knows.
ISO refers to how sensitive the capture source is. With film it is set throughout the film and cannot be changed but with Digital Cameras you can really do some cool stuff. So if it is how light sensitive it is that means the higher the number the more light it absorbs. So Higher means brighter and lower means darker.
This makes ISO a great way to work around exposure issues in low light. However there is always a price to pay. Raising the ISO also increases grain. Grain refers to the crispness or sharpness of the details. So you should know how that affects the picture over all.
One last note on ISO, it is worth maxing it out and getting a well composed photo with the right shutter speed and focus depth. So don’t be afraid to use it in high amounts if it supports a great photo. But if it's a crutch you will be limiting yourself so make it a last ditch effort.
This one is an easy one when it comes to practice. Go out into a setting that pushes your exposure boundaries. What you are gonna want to do is get the aperture and the shutter speed to be perfect but still need to increase the exposure. At this point you increase the ISO. This way you can start to see the effects it has on the photo and even find your comfort zone.
An even easier way is to look up your camera’s native ISO. A quick google search will give you a number and that’s basically the max before your video starts getting really grainy. For my camera it is a little above 12000 but I notice the graininess starts to take over so I don’t push 8000. That’s my ISO comfort zone. Go find yours.
Get to shooting!