So one of the issues that comes up when first starting photography is about how to get your photographs in focus, especially when photographing large groups. So I am going to try to tackle this hopefully in a way that makes this understandable. This post will also explain how to get that beautiful blurry background that we all long for as beginners.
Every lens should have a range of aperture, on the kit lenses it should range from f3.5-16 or so. But before we get into that, what is aperture? In camera lenses it is the hole/opening that light travels through. This opening does two important things.
1. It controls the Depth of Field (DOF). Shallow DOF is what give images that blurry background.
2. It controls the amount of light that is let in. Which in turn lets you shoot in lower light.
Image via www.nobadfoto.com
So the image above is a great visual for what is going on with your lens shutter when you are saying a photo. Smaller the number, more light. The larger the number, less light.
I took a series of photos to show what happens to your background and your subject as your aperture changes. I took these with a Sigma 35mm Art lens starting at f1.4 and moving up to f16.
Notice how the curtains and the center piece slowly come more into focus? That is the Depth of Field changing. Using a shallow DOF is great if you are taking a portrait and want the background to not distract from the image. Many photographers love to use a small aperture to bring the focus to a specific area of the photo. Usually in portraits to draw your attention to the subjects eyes.
So how does one use this knowledge to take group photos? Well there are several things you can do. One is to use a larger aperture, or if you are in a low light if you can get everyone in a straight line you may be able to get them all in focus. But your best bet is to use a large aperture. (You may need to use a flash or bump up your ISO for this.)
This image was shot @ f1.4. I used a led light to show the focus, but I wanted to illustrated the DOF with my amazing models. If you expand the image you may notice that there is a plane of focus, that the figures on the ends are out of focus and the ones in the middle (and parts of others) are in focus.
This image was also shot at f1.4 but I moved some of the figures into the focus plane. This is one way to get multiple subjects in focus.
This image was shot at f8. Notice how just by changing aperture to change the Depth of Field we get the figures into focus? Rad! This also works on people too! Arthur “Weegee” Fellig when asked how he got amazing images on a consistent basis he replied “Simple. f/8 and be there.” ecause he was shooting at f8 and knew his distances he was able to document what he was seeing and keep it in focus.
hooting with a lens that has a fixed aperture will help you immensely. Many of the kit lenses will change as you zoom. But knowing what aperture you are shooting at, no matter what lens your are using, will help you control the look of your photos. The cheapest options to be able to get those beautiful photos with the blurry background is the 50mm 1.8. They can usually be found for under $100 and are fantastic.
Now hopefully gives you some help on the portrait side of things. But for many of us when we startup we like getting out and taking wonderful landscape photos. So what aperture do you use for that?
Well ideally you will have your tripod with you so you can shoot at whatever shutter speed you need to. But as you have seen in the portraits above you have a shallow Depth of Field you will have parts of your frame not in focus. So by moving to a f5.6 to a f11 you can maximize your DOF and get more of the landscape in focus.
The above images were both shot at a smaller (larger number) aperture. The image of the waterfall I shot at f22 for several reasons. I wanted everything to be in focus as well as being able to slow my shutter speed in order to get the water to have that smooth effect. The bottom image was shot at f5.6. I had just finished a family session and wanted to get this landscape shot. I did not have my tripod so I shot at as low a shutter as I could while hand holding the camera. But in both I was able to get the desired effect.
In general if you know your camera, and you take the time to make you image. You can get your desired result.