Canon 5D Mark III Focus Buttons

How To Nail Focus On Your DSLR Every Time

In Photography by Jerad Hill35 Comments

Focus is an issue no matter how good your camera is. There is no perfect camera that will nail focus each time in every situation. Even the top dollar DSLR cameras have issues with sudden movement and low light situations. The more movement and the lower the light, the harder time it will have. Occasionally it is even hard to pull focus in perfect lighting situations. Over the years there are a few things I have learned to do that assure I get perfect focus “almost” every time. I may attempt to record a video explaining this process. The more I write, the harder I realize this is to explain without being to physically show you everything I am talking about.

Before I dive into my setup on my Canon 5D Mark III I want to mention that I have had this setup on my previous camera which was the Canon 5D Mark II, Canon 60D, Canon 40D and my very first DSLR camera, the Canon 20D. For those of you who use Nikon, I know there is a setup to achieve this as well.

There are a few tools you can use to make it easier to keep focus. The main tool is a tripod. If your subjects are not moving targets, a tripod is a good idea. If your camera is more of an entry level camera or a bit older of a model, I would suggest a tripod. Newer cameras are pretty amazing at detecting movement. Using a remote trigger can also help you keep focus because it keeps your hands off of the camera. You won’t need to go to these extremes unless you are shooting in very dark situations where you have to set your shutter speed down under 1/40th.

I have attached a diagram of the buttons I frequent on the back of my camera. Keep in mind that these are only buttons that I use to manage focus. There are other buttons that I use to manage exposure. Take a moment to look at the diagram and the labels of each button so you are familiar with what each does. Your camera may have different labels for the buttons and if your camera is not a 5D Mark III, the buttons are most likely located elsewhere. If you are unfamiliar with where these buttons are located on your camera, refer to it’s manual. I had to refer to my camera’s manual so I could make sure I used the correct names for each button. I had my own names for them but did not want to confuse anyone.

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My process will only work if you are shooting in Manual Exposure Mode, Shutter-Priority AE or Aperture-Priority AE as far as I know. I rarely shoot in anything other than Manual Mode.

Canon 5D Mark III Focus Buttons

There are a few settings that I changed in my Canon 5D Mark III to make using these buttons easier. The first thing I did is disable shutter button auto-focus. This means that when I push the shutter button down 1/2 way on my camera, the camera does not attempt to focus. I disabled this because while shooting weddings, things change quickly. Every time I touch the shutter button, which sometimes is on accident, I do not want my camera to attempt to refocus. I want total control over when my camera attempts to adjust focus. On Canon DSLR’s, this is a custom function you must change in your camera’s setup menu. Each camera has a different location for this setting. Every Canon DSLR has a different menu system, so it would be hard for me to explain it to you. Just Google search it or look through your camera manual.

I also changed my cameras focus mode to AI-Servo (this is a Canon setting, I believe it is called AF-C for Nikon cameras). Default is OneShot. OneShot is good for situations with no movement or if you want focus to stay put. If you are shooting landscapes, OneShot is just fine for you. However, OneShot autofocus operation makes it challenging to maintain focus at a wedding or if your subjects have a tendency to move. AI-Servo is for moving subjects. AI-Servo tells the camera to be ready for movement using predictive autofocusing. This is not a perfect system, but it helps a lot. OneShot stops the camera from attempting to refocus every time during a set of burst shots when you hold the shutter down to capture multiple photos in a burst. AI-Servo allows the camera to search for focus, however, this is only going to work if you hold down the AF-On button while you are shooting.

I still use my camera’s autofocus, I just do not allow autofocus to take place when I touch the shutter. In my diagram, notice the button labeled AF-On. That button tells the camera to go ahead and autofocus. Using that button, I pull my focus. There is a process to my focus beyond separating autofocus from shutter release. Let me try my best to map that out for you. In the future I may try and record a video showing exactly how I do this.

Step 1 – I frame my shot: Before I can choose who or what to focus on I have to have an idea of how I am going to frame that shot. At weddings, this is a quick decision that mostly involves using the rule-of-thirds to place my subject(s) in the frame. I don’t get carried away with off-center shots or creative placement until I have nailed a good solid shot. After I have my main shot nailed I may play around with placement and framing.

Step 2 – I set focus: In most wedding photos, especially the unposed shots, there is a main focus. This makes it easy to decide where to focus. 95% of the time I am able to use the AF-On button to pull perfect focus on my subjects. When my shot is framed, I press the AF-On button to focus on my subject. If my subject is not right in the middle of my frame, I point my camera directly at the person or object I want to be the center of focus and then reframe my shot. On rare occasions doing this will result in the subject being out of focus because I moved my camera after pulling focus. I use all prime Canon lenses, so I don’t have this problem nearly as much as I would if I was using an entry level lens that has more issues with banding.

If I can not get good focus because of the placement of my subjects or objects in my frame, I use the AF Point Selection button which allows me to move the point of focus from the center of my frame to any other location. Depending on how many points of focus your camera allows for, this can mean you have a lot of options, or just a few. Regardless, you will have options to move the focus point elsewhere.

Using the Multi-Controller Switch you can move the focus point from the center to any of the other focus points. Some cameras do not have a Multi-Controller Switch but most have a 4 position switch that allows you to go up, down, left and right.

In weddings, I choose the Bride as my main focus and I focus in between her eyes in an attempt to make sure her eyes are in perfect focus. I try to align the groom so that he is also just as focused as the Bride.

In some instances, it is hard to pull focus even with these this process. When it is dark out and my camera begins to struggle with focus I use this 3rd step to assure I am getting sharp focus.

Step 3 – I Use Magnification: The Magnification button allows you to get in really close to your point of focus. Sometimes I will hit this button and zoom in 10x on to my subjects eye and then hit the AF-On button. If it is really dark out, I may just manually focus using the focus ring on my lens. To use magnification, I also have to turn on my camera’s electronic viewfinder screen. On my Canon 5D Mark III, using the electronic viewfinder (EVF) can help a lot in dark light situations. When I hit the AF-On button, the EVF will increase the exposure of the image so I can see my subjects better. When you press the shutter down to take the picture, it exposes according to your settings.

In this photo, the groom dipped his bride so there was constant motion. My subjects were not still when I captured this photo. There was movement. Because of my camera settings and my process for maintaining focus, I was able to grab this image with sharp focus in-camera.

Bonus Notes:

Your Shutter Speed and F-Stop can affect focus. During weddings, I try my best to shoot at 1/160th for my shutter speed. If there is sudden movement, I want to make sure I get it. Many times I have been shooting at 1/100th or 1/125th and my subject ends up a bit soft. I hate soft. I want tack sharp focus every time.

It is also easy to miss focus if you are shooting at a wide F-Stop. This means that the lower the F-Stop number, the easier it is to miss focus. This is because of the wider your F-Stop, the shallower the depth of field. To explain further, this means that the focus fall off is much quicker. My ideal F-Stop is something higher than f5.4. All of my lenses are either 2.8 or wider with my widest lens being 1.2. If I was to shoot at f1.2, I could focus on the tip of my subject’s nose and their eye would be blurry. Even if the widest F-Stop your lens has is a 5.4, I suggest you try and keep your F-Stop at least 3-4 stops away from wide open.

It is not easy to shoot at 1/160th and f5.4 if you are not shooting outside during daylight. This is where ISO comes into play. On the Canon 5D Mark III I can shoot at 5400 ISO and get very usable photos. During the wedding reception, I often have my camera set to 1/160th shutter speed and f5.4 to make sure I capture movement and nail focus even when subjects are moving around and dancing. This means increasing my ISO and during a nighttime wedding reception I will set ISO very high. It is easy to get rid of noise in your image using modern versions of Adobe Lightroom or Photoshop.

I don’t like to try and sharpen out of focus images in Photoshop or Lightroom. I prefer to nail focus in camera where it is done best. Attempting to bring back focus in an image in post-production never looks right. If I do any sharpening in post-production it is to add intensity to an image.

My Last Thought On Focus:

We spend a large part of our day focusing on things. That is the main job of our eyes. I wear glasses to see far, so I know how important focus is. I get frustrated when I can’t focus on things. Because of this, I make absolutely sure the subjects in my images are in focus and that the focus is sharp. It is that extra attention to detail that I desire because I can’t stand not being able to focus on things myself.

I hope that this article didn’t confuse you. Camera settings are difficult to understand and they take practice to master. Check out my free course “Ditch Auto – Start Shooting in Manual” which will teach you the fundamentals of manual settings on your DSLR Camera.


  1. This is exactly what I needed, thank you so much! This is so well written and it answers a lot of my questions. I posted your link to my fellow photography graduates!

    Simple, well written, very informative! Thank you!

  2. I own a 5D Mark 3. I’ve been using the AF-ON button to focus for over two years now. I never knew focusing with the shutter button could be turned off. How do I turn the shutter button focus off?

    Thank you,


  3. No worries, I found how to disable the focus on the shutter button!


  4. I use one of these methods. One thing you mentioned about shutter speed leads me to ask the following; how do you keep your SS at 1/160th ? This is one area I struggle with. I guess I may answer my own question. Is it because of manual settings? I love manual, but feel like I am wearing my wheel out when shooting manual. 🙂
    Thanks for the article and any tips.

    1. I love manual mode, Just set you Shutter speed, aperture and ISO by pointing your camera to the skin of your subject to get the right exposure. And you’ll never need to set it again unless their is a change in the amount of ambient light(example: you are shooting indoors, and you need to shoot outdoors, then you if you outdoors, you need to set it again).

  5. That was really helpful and informative, thank you for taking the time to give such a thorough explanation, I’m sure it must of taken a good deal of time to nail down.

  6. Hi Jerad,
    I would like to say that you are the first one in my 40 years of photography (12 in digital) that finally made sense of focus and didn’t just try to pass it off as soft or out of focus images as a digital annomally. When I shot with film and prime lens in manual and split prism screens as well as preset focus distances and proper F stop, there was never an image that I took that was out of focus. I did wedding photography for 12 years (35mm) with about 15-20 per year. I have not shot a wedding in the last 15 years especially with digital and auto focus and not sure I would want to. I never used auto focus of any sort back then and the majority of my photos were stationary or slow moving as is in the wedding business (plenty time to focus) . For me manual focus is difficult if not impossible with the screens available today on a consistant basis. I have long considered buying a KATZEYE split prism or equal and trying it out because I still shoot in manual when ever possible for this reason as well as outside influences that may affect exposure. The other concern that I believe can be rectified is front or back lens focus depending on what lens or when it was made can do to focusing. There are times when the camera says focus is right-on but when reviewed you can see it’s not always so.

    The other thing that I dont rely on is in camera metering, never did, but that is not only a digital issue, but I seldom see photographers today at events I’ve attended take an external meter read and only rely on in camera lighting ratios (fill flash or equal) to be detemined by a computer. I guess that’s why there are many washed out highlights and loss of shadow detail (white wedding dresses and no shadow detail or dark tuxedo detail).

    Thank you very much for the article and for reading this comment.

    Regards Dave

  7. Is there a substitute for this article for Nikon users? I think I can translate the steps fairly easy, but what is the most efficient way for theAF-On option?

    Great read as is….


  8. Hi! Recently, I switched from a rebel to the Mark 2D, and I am having a really hard time getting my photos tack sharp even when I have it on manual. I think the issues may have been one of two things a two low of a fstop and the second mentioned in your post the One Shot verses Al Servio; however, my camera offers 3 settings in this category the middle one is Al Focus. Do you know what this setting is for??? Would appreciate your help. Going nuts trying to figure out what is going on as I did not have these issues with the rebel. Recently took a photo shoot for a friend who adopted and some of my photos were soft especially on faces. Also, do you have any suggestions on shooting people with fair skin. In the photo shoot I mentioned one child was very fair with blond hair and brown eyes and the others were brown hair brown eyes and the child who was fair ended up looking soft. In a case like this using your tips would you hold your focus on that child even if they are not in the center of your photograph??? Hope this makes sense? Thanks, Kelleyn

  9. YOU need to be an instructor for!
    This was spelled out easy and precise!

    Thank you!

  10. Great article! I’m an enthusiast and just upgraded (again) to a 5d III. I will be trying everything in this article!

  11. Great reading, easy to follow and I’m going to pick up my mk3 and try what you suggested right away! Thanks! 🙂

  12. This post of yours is really worth reading i was really fed up of taking some noisy and unsharp shots.This post takes me towards the new aspects of photography.I have a 5d mark iii but when i shoot with it and see the results it feels like the shot is taken with a beginner dslr. The image quality is well set to raw and i shoot at a iso of 100 not more than that.I only get some sharp images when shooting indoor at an f/stop 0f 8 or higher but then too not fully satisfied with the shots.The quality of image seems to be very low.
    Is there any mistake i might be making could you please help me out with it.

    1. I have same issue i switched from APS-C camera to 5d mark iii full frame and i noticed that my pic from APS C was more sharp. and from mark iii 🙁 am not satisfied. I think there is another issue of full frame its sharpness is lower than the APS-C . Searching for some experts advice.

  13. This was so great! Thank you for taking the time to explain! You answered all my questions so simply! Genius!!

  14. Great article!
    Just to throw in one thing I have just learned the hard way (sigh, is there any other way to really learn?) is that in the AF-Servo AF mode the Canon Flash’s IF AF-assist system won’t activate and the camera is left to focus on it’s own.
    To use the AF Assist system you need to switch the 5DIII body back to AF One Shot mode.
    I’m not sure if the rest of the Canon bodies work the same way (I don’t remember my 5DII working like that tbh, must go check) but it’s one of the few reasons to switch back to One Shot from Servo mode when BBF

  15. Hi,
    Excelent post. When you use AF button, do you turn focus button on AF or on MF, thank you

    1. Author

      I leave it on auto focus because otherwise that button would not do anything because it would assume that you wanted to manual focus your lens. Thanks

  16. Excellent article Jerad – easily the best I’ve read on focussing. I’m a little late to the party, but better late than never.

    BTW, did you ever get to making that video? If yes, can you please provide the link?


  17. Excellent explanation. I definitely had issues with this and these steps will greatly help me.
    Thank you so much!!!

  18. Thank you sooooo much for this post! I have been struggling with this for so long now, def going to try this out!

  19. Hello,

    Is is an amazing article, and very helpful!!

    Just a question, because i use almost the same buttons settings, how is programed you shutter button?

    Mine is to Manual AF Point Selection, and after half pressed, i move the multi controller switch to focus my subject? It makes sense to you?
    My AF-ON button is to Auto Focus as yours.

    Best Regards,
    Carlos Antunes

  20. excellent issues altogether, you just won a new reader.
    What would you recommend in regards to your submit that
    you made some days in the past? Any sure?

  21. Since this is an older article, the image you had of your cameras buttons & selections no longer shows. Might you still have that image? If so, can you send it to me please?

    1. Author

      I will have to check. I recently had an error happen with the server hosting my website and lost a lot of images from my website. I will email them to you when I find them. Thanks!!

  22. I’m unable to view your images. I tried 3 different computers and still not able.

    1. I had a problem with my server and need to add a bunch of images back to my website. I will try to get this up today as soon as possible.

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