- How to Take Better Food Pictures: Ditch the Flash
- How to Take Better Food Pictures: Stabilize Your Shot
- How to Take Better Food Pictures: ISO
How to Take Better Pictures
Part 4: What is Aperture?
by: Ben Powell
As I progress in my photography, more and more friends have come to me seeking photography advice. I’ve already written a post advising people why they should get a DSLR, but I guess I’ve kinda left them hanging a bit once they’ve gone off and purchased those DSLRs. So, even though this breaks the progression of the "food photography tips" I had been planning, due to popular demand I will try my best to explain this whole aperture business.
The first thing you need to understand is that getting good photographs is all about learning to control the light that comes into the camera.
There are THREE things that impact how much light gets into your camera:
2) Aperture (f/stop)
3) Shutter Speed
Shutter Speed, Aperture, and ISO as displayed on a Rebel t2i
ISO and aperture are a little more abstract and tricky to understand than shutter speed. I already wrote a guest post detailing ISO, so check that post out first! And now for aperture. Aperture is how big the opening is in the lens. This opening gets bigger or smaller depending on how much light you want to let through. The bigger the opening, the more light that gets in, and the brighter your photo. This opening is designated by the f/stop. You see the letter "F" and a "/" and then a number. That number is the size of the opening, but in a counter intuitive way. The bigger the number, the SMALLER the opening. I say again:
BIG f/stop number = SMALL opening = Less Light
SMALL f/stop number = BIG opening = More Light
Wide Aperture vs. Small Aperture
Get it? Got it? Good. But you see, it doesn’t stop there, because you might be thinking: "Well, the more light that gets in, the better lit the picture will be in the end." And in general you’re right, because more light means it’s easier to get a well exposed photo. But the aperture does this interesting thing based on the physics of the lens called depth of field. This depth of field effect is what typically differentiates "pro" looking photos from the photos you take with your cell phone. So here’s another way of thinking about the aperture:
BIG f/stop number = MORE depth of field = Everything in focus
SMALL f/stop number = LESS depth of field = Only certain things are in focus
Confused yet? Let’s take a look at some examples. Check out these photos I took of the 5th Harry Potter book (just finished it!). On the far left (small f/stop number), I’m focused near the bottom of the page, and you can see how only certain lines are in focus. But as I increase the f/stop (number goes UP), more and more gets in focus.
Click on the image for a better look
Let’s look at a people-example, too. In these portraits I quickly shot, you can see how Taylor is nicely in focus and the background fence is a pleasing blob in the background. But as I increase the f/stop, the fence gets more and more in focus, until finally you see how ugly it actually is.
In general, the blurrier the background, the more "artsy" and "pro" your pictures will look. Therefore, to get the strongest effect, you want to shoot with the aperture wide open, or that is to say, with a SMALL f/stop number. It’s not always that simple though. You may run into certain complications in certain shooting situations where you NEED more to be in focus. For example, when you’re taking a picture of your food on a plate, do you really want ONLY those veggies at the front of the plate to be in focus? Maybe you want to have the whole plate in focus! In reference to my Harry Potter shot, do I want to highlight a specific line? Or do I want to just have a clean shot of the entire page? Figuring out what you want the shot to look like in the end is key to mastering aperture.
So, how do you change the aperture (f/stop) setting? A good place to start with messing with your aperture is with the AV setting on your camera. This setting will have your camera automatically set everything else EXCEPT for the aperture.
You can then use the dial (next to M-Fn) to change the aperture value
Getting a good exposure is being able to carefully balance all three of the things I highlighted at the beginning of the post: aperture, shutter speed, and ISO. But when you’re just learning, better to eliminate the clutter and focus on just one thing. AV mode will let you do that so you can experiment. Keep in mind, if it’s a dimly lit room, you may still need to stabilize your shot in order to make sure there is no motion blur. (Tip #2!) Different lenses have different maximum apertures (how small the number can get). The heavier, bigger, more expensive lenses (and of course macro lenses, which are made to do this) can get REALLY wide (as wide as f/1.2 — meaning tiny depth of field/only a small amount in focus) but others can only get as wide as f/4 or thereabouts. You should still be able to experiment with it, but here is my recommendation for a lens to REALLY take advantage of aperture and learn how to use it: Canon 50mm f/1.8 or Nikon 50mm f/1.8. My sister Gretchen uses this lens almost exclusively, and she gets some very nice photos over on her blog.
Good luck! Please leave some links to pictures you’re taking, and whether or not you want any critique!
Ben is a freelance photographer and musician in the DC Metro area.
Learn more about him here: http://www.about.me/benpowell
Check out his photography business here: http://photography.benpowellmedia.com
And follow his project365 here: http://www.starvingartistry.net