How do you focus on a specific distance?

[milosh]

When using Nikon G type lenses (as far as I understood, Nikon lenses which have the G letter don't have an aperture ring nor a distance scale, and the only way to set aperture is through the camera), how do you focus on a specific distance?

For example if you want to focus on hyperfocal distance when shooting landscapes, how do you do that?

Is there some camera feature needed? Is this what the rangefinder feature is for?


Thanks

Milosh

[kencaleno]

Realise that wherever you focus using hyperfocal distance, that half that distance to as far as you can see,will be acceptably sharp. Any where over 30 feet from you just focus 1/3 into the distance.here's atrick I use for getting everything in from 2 feet 6 inches to infinity.
I set zoom lens at 18mm,and F11 set AF lock in menu,focus on your feet(about 5 feet away-Thats hyperfocal distance at F11 on 18mm), Holding shutter button halfway down,bring camera to eye level and make the shot. If you are to use a tripod, (recommended) you will need to measure 5 feet from sensor plane to focus. Ken

[Chip]

This FAQ on the DOF Master website has a good explanation. He also has a hyperfocal distance chart on his site that's helpful.

[Carl911]

Originally Posted by kencaleno

Realise that wherever you focus using hyperfocal distance, that half that distance to as far as you can see,will be acceptably sharp. Any where over 30 feet from you just focus 1/3 into the distance.here's atrick I use for getting everything in from 2 feet 6 inches to infinity.
I set zoom lens at 18mm,and F11 set AF lock in menu,focus on your feet(about 5 feet away-Thats hyperfocal distance at F11 on 18mm), Holding shutter button halfway down,bring camera to eye level and make the shot. If you are to use a tripod, (recommended) you will need to measure 5 feet from sensor plane to focus. Ken

Hi Ken,
Maybe you can clarify something for me.
If indeed at 18mm using F11 you get a hyper focal distance of 5ft I dont undedr stand in the Dofmaster Hyperfocal chart what you are meant to enter for 'Subject Distance'
It'd default is 10ft which as you said gives a 5ft hyperfocal but how & what decides the 10ft'subject distance' when shooting a landscape.
Im confused...

Carl

[fletch]

The hyperfocal distance isn't related to the subject distance. It is related to aperture, focal length*, and the camera (sensor size amoung other things). Hyperfocal distance is the distance from camera to focal point the provides you with acceptable sharpness (in focus bits) from infinity to as close to you as possible.

You will notice on DoFMaster once you have set the camera, aperture and focal length the hyperfocal distance doesn't change, no matter where you place the subject.


*I'm sure someone more technical will dispute this as you can argue that focal lenght isn't a factor in DoF or that it is or some other technical gobledegook. However to keep it simple it does!

[Carl911]

Originally Posted by fletch

The hyperfocal distance isn't related to the subject distance. It is related to aperture, focal length*, and the camera (sensor size amoung other things). Hyperfocal distance is the distance from camera to focal point the provides you with acceptable sharpness (in focus bits) from infinity to as close to you as possible.

You will notice on DoFMaster once you have set the camera, aperture and focal length the hyperfocal distance doesn't change, no matter where you place the subject.


*I'm sure someone more technical will dispute this as you can argue that focal lenght isn't a factor in DoF or that it is or some other technical gobledegook. However to keep it simple it does!

Thanks fletch,
thats what I kind of thought but then it begs the question, why bother to put a 'subject distance' at all as it seems irelevant if you know everything within a certain distance will automatically be in focus.

[fletch]

If your subject was closer than the hyperfocal distance for your combination of settings it is usefull to know how much will be in focus.

[OsmosisStudios]

Originally Posted by milosh

When using Nikon G type lenses (as far as I understood, Nikon lenses which have the G letter don't have an aperture ring nor a distance scale, and the only way to set aperture is through the camera), how do you focus on a specific distance?

G means the lenses dont have an aperture ring and therefore use the camera to set aperture: thats all. All my lenses have distance scales, and 2 are Gs. Only the lower-end lenses dont have them (the 18-55s, 55-200s, etc). My 18-70 and 70-300 both have a window on the top side of the lens with a distance scale. The 70-300 even has an IR marker.

[Carl911]

I must be doing something fundamentaly wrong.
I went out yesterday to take some more pictures at the side of a canal.
I tried out this Hyperfocal theory.
Using my 17-85 canon lense set at f11 & at its widest of 17, I focused the camera roughly 5-6 foot in front of me on say a piece of grass. I then moved the camera up to take the full picture keeping my original focus and took the shot.
what i ended up with was focus about five foot away and everything else was blurred.
So what am I doing wrong?

Carl

[milosh]

Ok, so basically it comes down to knowing your hyperfocal distance for the desired focal length and aperture and then focusing on an object on that distance, or little beyond that distance. As I guessed, there isn't some in-camera feature which would tell you on what distance you're currently focusing.
Ken, the trick with your feet is really handy. You can even measure precisely and know where to focus on your body.

Thanks everyone!