Why the Default Focus Setup isn’t Always Ideal.
Out of the box the D7500, like most (if not all) other DSLRs, defaults to initiate the auto-focus via the shutter release button. Because of the intuitive nature of this setup, there’s really nothing wrong with it. Especially since most people are expecting the camera to auto-focus without any extra steps. Most people are looking to do as little as possible to get good images. They don’t want to have to worry about it. Point-Shoot-Got it! No problem here.
Notice I said good images. Not great images. It’s a good thing to trust the tools that are part of the camera you’ve made a considerable investment in. There will be times, however, where these tools and features can actually get in the way or where we use them as a crutch and not really learn about the process of taking a great image.
The problem with the default setup is that every time we press the shutter button, the auto-focus (unless it is disabled) engages and tries to set the focus. It doesn’t matter if we already had the focus set. It will still try. It takes time to focus, even if it’s blazingly fast. Because of this, we could actually miss a great action or wildlife shot while waiting for the focus to set.
I may sound off as demonstrating a bit of hubris but I really do want to continually learn. Yes, I want to take great images. Yes I want to trust my camera. Yes I want to see what I can do to overcome some of the limitations imposed by the camera’s convenience features.
About back-Button Focus
A brief primer: Back-button focus is a technique by which you actuate the camera’s auto-focus using a button on the back of the camera, usually the AE-L/AF-L, instead of using the shutter button. This leaves the shutter button dedicated to metering and actuating the shutter. I consider it as a bit of a paradigm shift in how we go about making images.
Back-Button focus has been one area that I’ve been itching to try out with the D7500. I tried using it on my D90 last year but found that the AE-L/AF-L button was inconveniently placed too close to the viewfinder. This meant that, since I wear eyeglasses (read: pretty much blind as a bat without them), that every time I tried to use it I would smudge my them. To me, this is a huge annoyance. To others, it might not be. I think that partly because of this, I gave up rather quickly on trying to use it in real shooting.
So, I tried it out this week and I must say that, although it does take some getting used to, I really like it. The position of the AE-L/AF-L button is more suited to this on the newer body. It’s not even that big of a difference in distance from the end of the body or the eyepiece. Just enough to make it better. The big obstacle that I come across is myself. I find that I have to, for now, be mindful of the new technique and consciously set the focus using the back button.
Setting it Up
I won’t go into the details of setting it up in this post. I put this here as a placeholder for a link to a future post which will describe how I set it up on my D7500.
Trying it Out
The first thing I did was try it at home. This is where I discovered that simply setting the AE-L/AF-L button to focus wasn’t enough. Sure. I was able to focus using the back button but the shutter button still tried to engage the auto-focus so I had to disable this. It’s a bit pointless to have them both.
I had also set the shooting mode to CH (Continuous High) burst mode. This was so that I could have fun with the high rate (8 fps) that this camera had to offer during action shots. Here are some of the shots I took:
I found that I was able to get more shots with the burst mode and really had no difficulty with the auto-focus. What really made me like this was that if I wasn’t pressing the back button, I didn’t have the intermittent whining from the lens as it tried to determine focus that was already set. No delays in the shots.
I believe that I am now a ‘convert’ to back-button focus and will use it more often. In fact, I set it up on one of my custom modes so that it was readily available. Custom modes is a new feature for me, so I was happy to quickly find a use for it.