[CrazyNuts]

Hi everyone

I have been reading about hyperfocal distance over the last two days, and if anything I'm more confused than educated.

Can someone please explain to me in simple terms HOW to set my Sigma up for hyperfocus?

I have a K20D and want to get this method perfected before going to Canada next year on holiday.

The only distance indicators on the lens are the ft/m and infinity sign. Nothing else.

I know this topic has been covered numerous times, but I need education on the equipment I have so that I can grasp the method.

Thanks in advance

[RioRico]

The bad news: There ain't no easy way, Not with AF zooms. They don't have DOF scales on them. Even manual zooms with DOF scales are hard to set hyperfocal. Manual primes are easiest.

The not-so-bad news: Google for ONLINE DOF CALCULATOR and you'll find apps that will crunch numbers for you. You can use those to build a table of apertures vs focal lengths vs distances.

If you want a rule-of-thumb, try this: On your 10-20, set your aperture to f/11 and focus to 2m. Everything from under 1m to infinity will be in focus. But if you want a DOF range that doesn't extend to infinity, use a DOF calculator. Good luck!

[CrazyNuts]

There is a problem....

I don't know how to use the results from the DoF calculator

What do those distances mean at a given focal length and aperture?

What is (for example) 2m at 10mm f/11?

[JinDesu]

10mm zoom range, 2 meters is what you are focusing to, i.e. focus on an object 2 meters away

[CrazyNuts]

But then, there is another website which says that the 2m is the "middle" focus point and to focus on the subject HALF that distance.

I'm so confused it's not funny

[newarts]

Hi everyone
Online Depth of Field Calculator
I have been reading about hyperfocal distance over the last two days, and if anything I'm more confused than educated.

Can someone please explain to me in simple terms HOW to set my Sigma up for hyperfocus?

Under the worst conditions, 20mm @ f:3.5, the hyperfocal distance is about 20ft according to Online Depth of Field Calculator

That means that even wide open, if you focus on something about 20 ft from the camera every thing from about 10 feet to infinity will be in focus.

For any other lens settings even more will be in focus.

[RioRico]

Let's say we use this calculator: Online Depth of Field Calculator

I tell it I have a K20D, that the lens is set to 10mm focal length (its widest angle) and f/11 (that's the aperture I set via the camera), and that I've manually prefocused to 2m (set that on the lens focus ring after switching AF off). The calculator then says that my DOF extends from 0.36m to infinity. If I change the focal length to 20mm (its narrowest angle) then the calculator says DOF goes from 0.94m to infinity.

[CrazyNuts]

Ahhhhh I get it now

Thanks RioRico & NewArts

So I have to make sure that what's in my frame isn't closer than the NEAR LIMIT once I focus on my subject at a given distance (in this case 2m).

This will effectively give the impression that my whole image is in focus.

Riiiiiight. Think I'm starting to get the picture (pardon the pun).

The images on that link you guys provided cleared things up for me.