Today’s post is about something that we have been using for a few years now, and something that we WISH we had been using ever since we started shooting! There is nothing more frustrating then when you are shooting a portrait of your client, and the focus point you want to use is just outside of the composition you are wanting to shoot.
So you end up focusing on your client, re-composing the image, taking the shot and THEN have to do it all over again, because if you try and shoot two images in a row, the camera will re-focus wherever that focus point is now pointing and most likely go OUT of focus (or focus on something you did not want in focus). Annoying! Then you end up bobbing and weaving your head like a trained monkey all afternoon and your client thinks that there is something seriously wrong with you upstairs! :)
There has to be a solution to this irritating problem. Welcome to the world of back-button focusing!
Your camera has a myriad number of different points at which it can lock focus on your client, and depending on your camera of choice, some of those focus points are stronger than others. As an example, on the 5d mark 2 (a very popular wedding camera for many years), there are exactly 9 focus points. One in the center, and 8 others around the middle part of your frame. You can manually select (if you choose to do so) any single focus point and place that on whatever you want to be in focus on your subject (preferably the eyes of your subject if they are looking towards the camera), then hold the shutter button half-way down and wait for the focus square to beep and flash red, the camera has then locked focus, then you can just shoot the image, or re-compose the shot (while still holding the shutter half-way down which locks the focus point) and then shoot to get the composition you want.
The problem with a camera like the 5d mark 2, is that the center focus point is exactly nine times stronger then the outer 8 focus points, so if having your image in focus is important to you (which is should be!) then you will mainly want to stick with using that one only. The issue is, that most compositions don’t work with you focusing in the middle of the frame and shooting without re-composing your shot. So, you end up putting the center focus point on say your subjects eyes, focusing, then re-composing the shot and taking the image. Then, if you want to shoot another image similar to that one, you have to repeat the whole process. This really is inconvenient when shooting moments, because moments happen very quickly, and many times you need to shoot multiple images very fast which is hard to do when you are re-composing each and every shot!
“Well why don’t you just use the outer focus points dude?!” is something you might be thinking right about now. The problem there, is unless you buy a camera with TONS of focus points, there may not be one where you need it when you need it, and, the outer ones may be soooo weak, that you won’t be in focus most of the time anyway (unless you shoot Nikon, which in that case, most focus points probably work really well!!). The other problem with having the camera constantly trying to achieve focus every time you take a picture, is that even if you have a camera with powerful outer auto-focus points like the Canon 5d Mark 3, your client may move slightly out of the focus point you are using, and while you are shooting fast, the camera may miss an important shot while it was re-focusing.
As you can see in the above example, if I was using a 5d Mark 2 camera (which only has 1 powerful auto focus point shown here in the center of the frame), I would have to first put that focus point over the eyes of my subject, then re-compose the shot as seen above, then take the image. Then, for every new image I want to take, I would have to do that process over again. Slow and frustrating!
So, it is better to be able to tell the camera when to try and achieve focus, and when to shoot images, and the only way to do that is to separate the two functions using back-button focus!
With back-button focus, you press one button with your thumb to focus, and the shutter button only takes the picture. The shutter button never tries to achieve focus because it is disabled from that button. What this does, is let you, the photographer be in control of each and every image which means that images will be captured by your talent, instead of the horrifyingly non-talented awkward kid named “Hello my Name is Bobby Cannon” on auto! The less the camera thinks and the more you think, the better your life will be and the better your images will be!
So now you can focus on your subject using the most powerful focus point you have (or the one that is closest to the focus plane you are trying to achieve), then re-compose your shot and shoot as many images as you need without having to re-focus. As long as your subject stays on the same focus plane, you don’t have to re-focus!! Now, as you coach your client to get a great smile, or as moments are happening quickly, you can focus once, then fire away without the camera trying to constantly achieve (and miss) focus!
As great moments are happening in front of the lens, you can fire away and not miss a shot!
How to set up your 5d Mark 2 with back-button focusing:
1. Go to your custom functions menu shown here and go to C. Fn IV and enter it.
2. Once in C. Fn IV, you have 6 menus. You will want to change menu 1 (shown at the bottom of the above image) to option 2. What this does, is it changes the function of the shutter button so that it only activates the in-camera meter and takes images, and it moves the Auto Focus function to the AF – ON button on the back top right of your camera.
3. This adjustment is optional, but what this does, is it moves the auto focus button from the AF-ON button (that we just enabled in step 2) to the one right next to it, the AE LOCK button or the one you use to lock your exposure when shooting on auto modes (which we rarely do). Now, with this option enabled, you can focus using the AE Lock button and if you simply keep holding that button down after the camera focuses, it will also LOCK the exposure if you happen to be shooting in an auto mode. It’s also closer to your thumb, so finding it is easier.
On the 5d Mark 3, you can have both the AF-ON button and the AE Lock button on to achieve focus which is better in case your thumb slips from one to the other.
With this option enabled, you would not have to press this button to lock exposure, then press the AF-ON button to achieve focus as you would with it disabled.
1. To set your camera to back-button focus is different for each camera, so refer to your owners manual for cameras other than the one listed above.
2. If shooting at a shallower depth of field than 2.8, or if you are shooting a long lens in very close to your subject, be wary of re-composing a shot as your focus plane can change dramatically. In those cases, you will want to only use an auto-focus point that is DIRECTLY over the area you want in focus, and then do NOT re-compose your shot.
3. Spend time practicing this method as you need muscle memory to do this naturally. You DON’T want to try this out for a wedding unless you have used it for while and feel comfortable with it!
4. The camera will now take images even if you have NOT achieved focus. So, don’t assume a shot is in focus just because your camera takes the picture.
5. If you use an Expo Disk for color and exposure and are sick of having to put your camera on manual focus to take an image (you can’t take images unless your camera can focus when it is set to auto-focus), now you can shoot away since the camera no longer needs to focus to be able to shoot! Just press the shutter button any time to take an image whether or not you have achieved focus.