During my 31 Days to a Better Photo series, I talked about depth of field. I mentioned that your distance from your subject also factors in to the width of that band of envelope of depth of field.
It’s a subtle difference, but look again at the first and last graphics. The photographer is working with apertures of f/2 and f/2.2. These are very similar apertures. But if you look closely, the first image has a much narrower band representing the depth of field.
Why? Because you, the photographer, are standing closer to your subjects.
The closer you are to your subject the narrower your depth of field will be even at the same f-number.
If you have the 50mm f/1.4 lens and you’re shooting wide open at f/1.4 and you’re standing 4 feet from your subject:
But, with the same lens and aperture standing 10 feet from your subject:
Using my camera as an example, when standing 10 feet from your subject you have about 1 foot total depth of field. But at 4 feet from your subject, you only have 0.16 feet – this is about 1.92 inches!
If you have an iPhone you can install the DOF Master app (“there’s an app for that!”), but if you have any smart phone you can also bookmark the website and calculate it from your phone on the field. The Depth of Field Online Calculator can be found at: http://www.dofmaster.com/dofjs.html
You’ll have to know the make and model of your camera – why? Because full-frame and crop-frame cameras have different formulas. Crop-frame cameras already have a 1.5 to 1.6 magnification factor. You can read more about crop factor on my post, Full Frame vs. Crop Frame Sensors: What is Crop Factor?
Using the DOF calculator and entering the details of your lens and distance, you can choose the best aperture to make sure everything you want in focus will be sharp.
Did the numbers surprise you?
Hi Darcy! I stumbled upon your blog last night and literally spent hours reading through your posts. I love the way you explain things (and your sense of humor!)
I’ve gotten pretty good at knowing the technical aspects of using my camera but I found that all of your posts still had tips, tricks, or just different ways of thinking about things that are so helpful! And seriously, I had no idea there was an app for DOF!
Thanks so much for sharing with us. I look forward to being a regular reader from now on!
Welcome to m3b. Glad to have ya!
This couldn’t have come at a better time!!! I recently bought a new lens that has an aperture of 2.8…and sometimes when I photograph multiple people, one person is out of focus, while the other is in focus…so I need to just remember to keep my distance <3
Abbey – that 2.8 is the max aperture. You should be able to change it when you need to.
This is what I have been struggling with lately too… It just seems my photos are never as crisp as I would like them to be. 50mm/1.8 Nikon D7000…. I’ve also noticed that if I have my aperture set around 2 & there is any sun in the background, I get too much chromatic aberration. Is this because my aperture is set too low?
That’s the one issue I have with my nifty 50…we have a tiny house so standing 10 feet away isn’t likely and then if I am able to stand 10 feet away, I feel like I do a lot of cropping to get the look I want the image to have. Still not ready to give up on primes, though
They take BEAUTIFUL images!!