Edit: I may be a little confused about what you mean when you say narrower aperture. When you focus stack, you will be using a relatively wide® aperture, if you are not, you will need a somewhat narrow(er) aperture to get sharper focus.
Focus stacking is usually done in post. The option in your camera will most likely just take a series of photos with the focal point changing slightly every time, and you can stitch those together later. Photoshop will do it automatically, or you can do it yourself with masking on different layers.
There are some cameras that will do the stitching for you. I know the OM-1 (the camera I generally use) does this, and probably other models. I tend not to use it though since it saves the end result as a jpg and I prefer to process my own images from RAW.
Edit: I may be a little confused about what you mean when you say narrower aperture. When you focus stack, you will be using a relatively wide® aperture, if you are not, you will need a somewhat narrow(er) aperture to get sharper focus.
Focus stacking is usually done in post. The option in your camera will most likely just take a series of photos with the focal point changing slightly every time, and you can stitch those together later. Photoshop will do it automatically, or you can do it yourself with masking on different layers.
There are some cameras that will do the stitching for you. I know the OM-1 (the camera I generally use) does this, and probably other models. I tend not to use it though since it saves the end result as a jpg and I prefer to process my own images from RAW.