It’s always a great shock when you see the actual size of a lens aperture. The stops between aperture sizes can be dramatic in actuality, but at times, they don’t look very dramatic at all. If you remember what a “stop” is, you’ll know that for every stop, you either halve or double your exposure. Exposure is controlled by three settings in your camera; shutter speed, aperture and ISO. So if someone says to you, “Increase your exposure by one stop for this photo,” you can either halve your shutter speed from 1/250th of a second to 1/125th of a second, enlarge your aperture size from F/11 to F/8 or increase your ISO setting from 100 to 200. Each of these three options would increase your exposure by one stop. Just remember, while you’re increasing your exposure equally with these settings, there may be side effects, such as changes that include motion blur or alterations to depth of field. Just keep that in mind.
I made a very cool graphic this morning that exemplifies the size of aperture settings in a lens. Check it out.
This graphic should give you an idea of what each aperture size is compared to others. I made the above graphic, but this one down below I found on Wikipedia. In it, the scale of aperture sizes goes all the way down to F/1.4, which is very huge.
So F/1.4 allows twice the amount of light in through the lens than F/2 does. Incredible.
I also wrote a post that discusses how aperture size can affect ISO settings when the camera is set to Auto ISO. Please give that a read. It’s a good post.
Anyway, I just thought I’d share this with you. Knowledge is power.