Getting To Grips with Manual Mode – Aperture and ISO

A User Guide to Explain Manual Mode focusing on Aperture vs ISO

In my last article, I helped walk you through how to choose the best DSLR camera for your needs. And it brought a lot of questions about how to USE a camera. There are SO many people out there who have wonderful cameras, but have never taken the time to learn how to use them. Although the auto modes can be pretty decent, if you want those crisp, bright, clear and clean images that you see other folks taking, you are going to have to start using your camera in Manual mode.

Don’t fret! There is plenty of help out there for you to learn! You’ll never hear me argue that manual settings on cameras can’t be confusing, and at first it will seem overwhelming. The only thing that you can do to understand is practice as much as possible and don’t be afraid to ask questions. In this article we will explore aperture and ISO. Both settings refer to the way that your camera sees and captures light. A helpful hint for anyone just starting out, use the viewfinder on your camera rather than using the screen to take images. Your camera will focus better as well as faster than using the screen.

(Please note that these images are taken of a Canon EOS Rebel T4i, your exact camera may vary as far as how to change the settings, but the images will still give a general idea.)


Show Aperture Setting

Common Aperture FigureBy definition, Aperture, also known as f stop, is “a space through which light passes in an optical or photographic instrument, especially the variable opening by which light enters a camera.” You are able to control the aperture on your camera. Changing the size that your lens opens up to will either allow more, or less light in when taking a photo.

Let’s look at some photos to see how light is affected when aperture is changed. As you can see, the lower the f stop the wider the lens opens and the more light will be let in. Your aperture will be shown somewhere on the screen of your camera and will say “f/2.8” or another number if using a different f stop.

Aperature 2.8
Aperture 2.8
Aperature 5.0
Aperture 5.0
Aperature 8.0
Aperture 8.0

As you can imagine, different light sources will require different apertures. Experiment outdoors and indoors to figure out how it works and which aperture will be best for your situation. After a while, you will understand it better and be able to know instinctively what your aperture should be. Taking a few test shots at the beginning will also help you decide which one works best for your needs.


Show ISO Setting

ISO (Pronounced I S O not as one word) is your cameras sensitivity to light. Your camera has a sensor in it, which is used to focus and assume the proper settings in auto mode, among other things. The most important thing to remember about ISO is that the lower the number you can get it at, the better quality the image will be. High ISO photos will have a lot of “noise” otherwise known as that grainy look to them. You should try adjusting your aperture (explained above) and shutter speed (explained in the next article) before cranking up the ISO in images for the best results. The higher the ISO, the brighter the image will be.

Your camera should have a button that says “ISO” next to it – that is the button that will allow you to change the ISO number. As you can see in the photo of the camera, it will be displayed on your information screen and will say ISO and the number that you have it set to.

All of the images were taken at the same shutter speed of 1/30 and aperture of f/2.8, only the ISO was altered.

ISO 200
ISO 200
ISO 400
ISO 400
ISO 800
ISO 800
ISO 1600
ISO 1600
ISO 3200
ISO 3200

You can see how the colors, crispness and vibrancy change with the different settings. Again, your environment will determine your settings, but experimentation will be instrumental in learning how to choose the right ones for the occasion. The more pictures you take, the better you will get.

If you want to read the other articles in this series, check them out.

How to Choose the Best DSLR Camera For Your Needs

Shutter Speeds, Light Meters and White Balance

Viewfinder, Screen, and Continuous Shooting


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Katie Reed

Katie Reed

Katie Reed is a 38 year old mom blogger from Salt Lake City, UT. She is married to the man of her dreams and together they have four beautiful boys. Dexter is 9, Daniel is 7, Chester is 5 and Wilder is 2. She writes about living with mental health issues while navigating motherhood. Her blog focuses on tips and tricks for moms, information and parenting news, kid-friendly recipes and crafts. She loves to reflect on the humorous side of parenthood and shares the reality of her life, with a "warts and all" attitude.

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