I asked my wife the other day if she had any questions about photography in general that I could use in a learning segment here. She thought for a moment and then asked, "Why is it when I take a picture with my iPhone, my subject and the background is all in focus...but when you take a picture with your camera, your subject is in focus, but the background is blurred?" Good question.
The answer is your aperture or f/stop. Apertures or f/stops on all cameras control your focus depth. All cameras, be it smart phones, DSLR's and point 'n shoot cameras have f/stops. You can change it on most cameras, but on your iPhone you cannot. If you're operating a camera where you can change the f/stop, you can use these settings as general guidelines: If I'm out and about shooting a landscape, with no general subject, I'll set my f/stop at F/11 or higher. Most of the time for capturing everything in focus, I'll even shoot at F/22. This will increase your depth of field and no part of the image will be blurred. If I'm shooting a portrait (where I want their face(s) in focus), I'll shoot at a lower f/stop to blur the background. Say F2.8 or F4.5. Make sense? No? Yeah, me neither. I'll give you a visual guide then.
The image of the monkey was captured at F/5.6. He was standing far enough in front of the tree branch in the background for it to be blurred or out of focus.
The image above the golden dome was captured at F/22. See? Everything in that image is in focus and nothing is blurred. This effect is commonly known as 'bokeh.' I don't personally use that word, and even the correct pronunciation of it is often debated. Some people say, 'boke-ay' or 'boke-uh'. I even heard it once as 'boo-kay'. Who knows? You decide. I'll have a Coke in the meantime.
So, all you have is an iPhone and you want to fake it with your photos? Wait for it. Wait for it. Yup. There's an app for that. If all you have is an iPhone and you want to fake that look when you take a portrait by blurring the background? The last time I used Instagram, it could do that. Otherwise, if you're really clever, you could use Photoshop.
IPhone f/stops are currently unchangeable. The iPhone 4s uses an F/stop of F/2.4 all the time. It sounds low, but at a 4.3mm focal length, it really isn't. The iPhone 5s uses an F/stop of F/2.2. Now, you're thinking - but that doesn't coincide with what you said earlier about lower-numbered f/stops. You're right. But keep in mind, those lenses in those cameras are teeny-tiny! Below is an iPhone shot I took in Montana.
Doing this blog post actually gave me another idea for another post on getting better photos with your iPhone. Stay tuned for that.
I am by no means an expert on aperture. I just know what works for me. Another thing to keep in mind is when you open up your aperture, like when you choose a lower number, like F/2.8, you're allowing more light to enter the lens for an exposure. When you close it down, like at F/22, you're allowing less light into the lens for an exposure. By doing this, you'll need to compensate by slowing or increasing your shutter speeds.
In any case, a wonderful photog friend of mine gave me this tip years ago: More F's means more in focus. Less F's means less in focus. Because keeping your focus, is well, half the battle.
Have a great week folks!