How do I get better Autofocus?

Started Nov 15, 2012 | Discussions thread
tedolf Forum Pro • Posts: 25,566
The best thing to do....

saywhathomie wrote:

tedolf wrote:

saywhathomie wrote:

Russ Houston wrote:

tedolf wrote:

Don't use auto focus. If you are shooting a scene with a known depth of field. Disable AF and use a fixed aperture sufficiently small to make the entire scene within the selected DOF. You might need to use lights if you need a small aperture.


Yep, autofocus on video is a pain. Better to just focus once, then switch to manual and leave it there. Especially if you're doing review videos, the camera won't need AF anyway.

Okay, just tried that and it didn't work. I can't bring the product up close or far away without it being blurry.

I'm shooting at 3200 ISO and f.25.

wide open so of course you are going to get the minimum Depht of Field. Stop down to f/8.0, manually focus on something about two feet from the lens and everything from 1.5 feet out to about four feet will be in focus.

You may need to turn on some lights to get adeequate exposure.

Do you understand the relationship between aperture and Depth of Field?


A little bit. I know wider aperture = blurrier background but that's about it. As I said, I'm still learning.

To clarify. I should manual focus on the item in the middle of the table, then it won't be blurry when I move it closer or farther back?

Here's a picture of my current recording setup.

P.S, I appreciate the helpful comments. I'm soaking it all in! 

is look at an on line DOF calclulator:

Then you will have exact numbers as to where the field starts and ends based on where you are focusing, what focal lenght you are using, and what aperture you will need.

This is all much easier with a manual lens where all of this stuff is marked right there on the lens barrel.

No offense intended I am just very curious:

How did you wind up with a $1,000.00+ camera if you don't understand basic photography stuff?


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