Do the terms aperture and depth of field make your head spin? I just got a new lens and the perfect one for teaching about aperture since wide open it is 1.2.
During some of my recent One-on-One Photoshop Trainings, I have had some customers who are relatively new ask me about exposure, depth of field, and how speed, ISO, and aperture all work together. So I realized that while many are familiar with these principals, some visitors to my blog, may not be.
So today I will be giving a brief lesson in aperture, mostly through bubble gum photos.
Here are some terms you will want to know:
Aperture – an opening that allows light in – it gets wider or narrower depending on the number.
Wide Open – when you hear the term “wide open” it refers to the widest a lens opens up. This will allow the most amount of light in. Prime lenses tend to open up more than their zoom lens counterparts. My newest lens, the 85 1.2, opens up to an aperture of 1.2. This is very wide. If set wide open, you will get a lot of light into the lens. This means you can shoot in very low light situations. It also means you get a very shallow depth of field when opened up.
Depth of Field – in simple terms this has to do with how much of an area is in a “field” which is in focus. The more wide open your lens and your setting for aperture, the smaller your depth of field. Shooting at 1.2 will be extremely narrow. See the 1st photo below. I clearly focused on the blue piece of bubblegum. You can see all others are out of focus. The further from my focal point, the further out of focus it becomes – going forward or backward.
The second photo has the same settings and you can see I focused on the red bubblegum on the table. Some of the bubblegum machine is in focus since parts are on the same plane. The rest of it and the bubblegum pieces are out of focus.
Stopping down – when you make the number bigger for your aperture, this is called stopping down. This means your depth of field becomes bigger, more is in focus, and you have less light coming in. To get proper exposure, you will need to increase the ISO and/or decrease the speed depending on your situation.
The 3rd photo is shot at f10. You can see that most everything is in focus except the furthest and very closest few gumballs. You can see my ISO increased and my speed decreased so I could expose correctly. If I was to take another shot at say f16, then everything would have been in focus, my ISO would have had to increase more. And I may have needed a flash to help light things if I could not get enough light in.
I hope you enjoyed this tutorial. Please come back for more – and subscribe to my blog for more updates. If you still want to learn about photography basics, check out this e-book explaining the nuts and bolts of photography.