Hyperfocal distance question
 

I have been trying the hyperfocal technique for some time and getting varied results but still need clarification please.

According to [url=http://www.dofmaster.com/dofjs.html]DOFmaster[/url] if I focus on a subject at 10ft using my wide angle lens at 13mm focal length the near limit of acceptable sharpness is 1.55 ft. Then it says the hyperfocal distance is 1.87 ft and depth of field extends 0.935 ft to infinity. So do I keep my camera focussed on my subject at 10 ft? Does this mean that whatever the subject distance is, the hyperfocal distance remains constant when using the same aperture, i.e. HF distance1.87 ft at f16 at 13mm focal length with Canon EOS 60D?

I have read that best results are gained "when focus is set at the hyperfocal distance". Is that what I am doing above? I don't want to get involved in the mathematics of it ( CoC and all that) but need some help.

I found this elsewhere and I think it answers the question.

Quote:
[I]"…. So, in practical terms, all you need to do is focus on anything at or beyond the hyperfocal distance. How, or what you focus on, whether it is in front of you or behind you makes no difference so long as the focus plane is at or beyond said Hyperfocal distance.

Personally, I start at f11, 25mm and look for anything about 10' away and focus on that using the back button. Having done that, then I'll start to
frame the shot."

HFD is a great technique when you have objects of foreground interest very close to the camera and still want the distance to be acceptable. If your foreground interest is 10 feet away though, the last thing you want to do is focus at an HFD of 7 feet. You have an option to focus on the object at 10 feet, to maximise sharpness there, and also improve sharpness at the horizon. Or focus a little past the foreground interest, say at 11-12 feet, which will still keep it sharper than focusing at 7 feet and also improve sharpness at the horizon even further.
[/I]

[QUOTE=Argee;79435]I found this elsewhere and I think it answers the question.

Quote:
[I]" look for anything about 10' away and focus on that using the back button. .
[/I][/QUOTE]

Not sure I follow that...... what's a 'back button'?

[QUOTE=GeoffWessex;79472]Not sure I follow that...... what's a 'back button'?[/QUOTE]

Geoff, the Back Button is AF-ON on Nikons. Don't know what it's called on other brands. You disconnect AF from the shutter button & use AF-ON to focus.

What confuses me though is
[QUOTE=Argee;79435]Quote:
[I]"…. How, or what you focus on, whether it is in front of you [B]or behind you[/B] makes no difference so long as the focus plane is at or beyond said Hyperfocal distance.[/I][/QUOTE]

How can you focus on something behind you, and how can something behind you be at or beyond Hyperfocal distance?

:confused:

Chris

Edit: Oh, I see... focus on something, anything, anywhere, at the right distance, before recomposing. :o

[QUOTE=greenwing;79483]Geoff, the Back Button is AF-ON on Nikons. Don't know what it's called on other brands. You disconnect AF from the shutter button & use AF-ON to focus.[/QUOTE]

Also on the Canon it is the same.


[QUOTE]Edit: Oh, I see... focus on something, anything, anywhere, at the right distance, before recomposing. :o[/QUOTE]

Yes it is confusing. But now I realise the actual hyperfocal distance on a chosen aperture doesn't change. Only your choice of lens focal length will affect it, then work out your depth of field accordingly.

[QUOTE=Argee;79489]Also on the Canon it is the same.




Yes it is confusing. But now I realise the actual hyperfocal distance on a chosen aperture doesn't change. Only your choice of lens focal length will affect it, then work out your depth of field accordingly.[/QUOTE]

Do you carry a PC and monitor on your back ?[IMG]http://www.digitalcameraworld.com/forum/images/icons/icon7.gif[/IMG]

No. With a little pre planning I attach the lens I want and have a chart in my bag if I need it, and an app on my phone to refer to also which quickly shows me the basic settings and hyperfocal calculation, but failing all that I instinctively know that if I set the aperture usually at f11, and my subject distance at whatever I need to gain optimum sharpness at, and it is beyond the hyperfocal distance of the lens aperture, I get an acceptable result. It is worth noting however that "acceptable sharpness" in front or beyond the focal subject is helped with a little raw post sharpening. Have a look [url=http://www.flickr.com/groups/hyperfocal_technique/][B]here[/B].[/url]

[QUOTE=Argee;79433]I have been trying the hyperfocal technique for some time and getting varied results but still need clarification please.

According to [url=http://www.dofmaster.com/dofjs.html]DOFmaster[/url] if I focus on a subject at 10ft using my wide angle lens at 13mm focal length the near limit of acceptable sharpness is 1.55 ft. Then it says the hyperfocal distance is 1.87 ft and depth of field extends 0.935 ft to infinity. So do I keep my camera focussed on my subject at 10 ft? Does this mean that whatever the subject distance is, the hyperfocal distance remains constant when using the same aperture, i.e. HF distance1.87 ft at f16 at 13mm focal length with Canon EOS 60D?

I have read that best results are gained "when focus is set at the hyperfocal distance". Is that what I am doing above? I don't want to get involved in the mathematics of it ( CoC and all that) but need some help.[/QUOTE]
Depth of Field (DOF) for the values u have said here, i.e. Aperture f/16, Focal length 13mm for your camera (Canon 60D) comes to 2 feet. That means if you set the above values and focus at 2 feet, everything from 1 feet to infinity should be acceptably sharp.

For knowing how i arrived at this magic figure of 2 feet, you could check here [url]http://photographypoints.blogspot.in/2012/09/hyper-focal-distance-simplified.html[/url]

If you know the Hyperfocal distance and focus on it, everything from half that distance, to Infinity, will be in focus. Ed.