Autofocus vs. Manual Focus Question

[Cody21]

Curious about when you use AF mode vs. Manual Focus.

For instance, when taking a Landscape Photo - I'm shooting say f/8 or f/11 (my "sharpest" lens setting) at some shutter speed. When things are dark and I'm in need of a tripod, my AF points seem to get confused, for lack of a better word. I'm thinking it just best to manually set my lens to Infinity after setting a focal length (e.g., 100mm) and leave AF turned off.

So just curious if you have a general rule of thumb when YOU use AF or not and whether I am seeing this right -- e.g., just setting to Infinity for landscape shots.

thanks all.

[Perry Ge]

Don't focus to infinity with landscapes, and don't autofocus either. And forget that hyperfocal stuff, it won't be useful unless you really fully understand it.

I do a lot of landscapes, and usually I'll use manual focus and focus on something of interest in the foreground, about a third of the way into the frame (because remember, your depth of field is not equal either side of the plane of focus, there is more depth of field behind it). Generally, you want your focal point in the landscape to be the most in focus.

But sometimes, if I'm shooting at say, f/16 I just turn the manual focus ring so that it's somewhere between minimum focusing distance and say, 2/3 of the way to infinity, and just leave it at that.

[Cody21]

Thanks Perry ... I'll give that a try.

[Glenn NK]

If you want the focus to be set at infinity, do not rotate the barrel until it stops, as AF lenses will rotate past infinity, and at this point, they will be OOF.

Old style MF lenses did not do this.

If I want the focus to be truly at infinity, I pick some object that's a long way off. In practical terms, an object at several hundred yards/meters is at infinity.

[Cody21]

Glenn - in doing so, do you use AF? or Manal Focus using the Focus Ring? Or turn it to Infinity but turn it back a few mm ??

[Glenn NK]

Glenn - in doing so, do you use AF? or Manal Focus using the Focus Ring? Or turn it to Infinity but turn it back a few mm ??

If I want infinity focus, I just do AF on something a few hundred yards/meters distant.

One could also carefully manually set the lens to infinity by aligning the infinity mark with the pointer.

[Cody21]

Got it... Thanks