One of the interesting things you can do with some modern mirror-less cameras is change the size of the AF area to suit the subject you are dealing with.
On my Fujifilm X-E2 I can press the AF button to display the little green AF rectangle and then steer it around with the multi-controller buttons - much like Pentax, Nikon, and Canon users can do with their respective systems. Good to do if your subject is not dead-centre.
What you can also do is press and twirl the little control thumb wheel just above the multi-controller and watch the green AF rectangle get bigger and smaller - it is selecting more of the sensor to use as the AF measuring pad as you do this.
Why do this? Well, if you have a subject that has intense contrast and detail, you can use the smallest size of rectangle and get sharp focus...but if your subject is dimly lit or lacking in contrast you would be waiting a long time for this small rectangle to work.
Push, twirl, and make it bigger. The camera will have more information coming into the focusing circuit and will lock onto focus faster and better.
The bigger spoon in the title is just this - if you go to dinner with a bigger spoon, you get more stew. Grab the AF info with a bigger box and you get more stew...
Can you tell this post is being written close to lunchtime?