About hyperfocal distance..

throndor · 09-09-2008, 01:22 PM

Read a couple of texts but still not sure of some issues..

1- So there is no way to get things in focus from 1 inches to infinity? (i've seen some photos where they shot the beach boulders and the sea, both of which were pretty in focus?)

2- When my hyperfocal distance is longer than 2 meters, how do i focus on something that is at that distance.. The lens just focuses on things nearer than 2 metres and the rest is just "infinity".. so how is focusing on something at 4 meters and 30 meters different?

deejjjaaaa · 09-09-2008, 01:29 PM

Originally Posted by throndor

Read a couple of texts but still not sure of some issues..

1- So there is no way to get things in focus from 1 inches to infinity? (i've seen some photos where they shot the beach boulders and the sea, both of which were pretty in focus?)

something like fisheye 8mm @ f32 ?

Gooshin · 09-09-2008, 01:33 PM

Originally Posted by throndor

Read a couple of texts but still not sure of some issues..

1- So there is no way to get things in focus from 1 inches to infinity? (i've seen some photos where they shot the beach boulders and the sea, both of which were pretty in focus?)

2- When my hyperfocal distance is longer than 2 meters, how do i focus on something that is at that distance.. The lens just focuses on things nearer than 2 metres and the rest is just "infinity".. so how is focusing on something at 4 meters and 30 meters different?

you cannot trust your camera to focus using the hyperfocal distance rule, SOMETIMES it does it but most often it will just spin to infinity.

k

throndor · 09-09-2008, 01:33 PM

so answers ;

1- if you wanna shoot a scene like i mentioned in the previous post, you should have something with a short focal lenght..

2- find something at hyperfocal dist and try to manual focus it in short movement range of the lens between 2 meters and infinity?

True?

stevebrot · 09-09-2008, 03:40 PM

Originally Posted by throndor

Read a couple of texts but still not sure of some issues..

1- So there is no way to get things in focus from 1 inches to infinity? (i've seen some photos where they shot the beach boulders and the sea, both of which were pretty in focus?)

Yes, there is. It is called a view camera. With appropriate use of tilt, swing, and shift you can put the focal plane pretty much wherever you want.

2- When my hyperfocal distance is longer than 2 meters, how do i focus on something that is at that distance.. The lens just focuses on things nearer than 2 metres and the rest is just "infinity".. so how is focusing on something at 4 meters and 30 meters different?

You can either:

Focus manually using DOF preview to evaluate the results

OR

Use an older lens with focus/DOF scales, measure the distances to your subjects, and focus manually using the scales.

Either way, your results may vary. Remember that hyperfocal only promises acceptable focus within the stated range.

Steve

flyer · 09-09-2008, 04:52 PM

If you browse a little bit, you can find on the internet some depth of field scales that can be used to find out what distance to focus at a given f- stop to be on hyperfocal.

kerrowdown · 09-09-2008, 05:13 PM

Switch to manual focus, then you can control on what you want focussed within the range. I seem to remember back in the old days (but I may be wrong) it was in thirds i.e. one third in front and two thirds behind what you actually focussed on, that would appear sharp due to dof.

On older style lens the dof scale was marked so you could see at a glance for any given aperture the "apparant" distances that would be in focus. You would align the infinity mark with left hand aperture setting and then read the right hand side on the distance scale for the same aperture value. All in between would be good.

I feel really old now.

*Mechan1k* · 09-10-2008, 08:14 AM

A few of my Super Takumar lenses have HF markings on them ... I usually set it to f/8 if i want to snap off a few shots when ... say driving ... and I set it on the HF marker on the lens and take the shot.

Billgscott · 09-11-2008, 02:34 AM

Try here for DOF and hyperfocal distances. Online Depth of Field Calculator

Also try a DEPSSI card that gives this info and Sunrise and Sunset points at different times of the year. at Blue Pond Images

Enjoy.

mattdm · 09-11-2008, 06:50 AM

The important thing to remember is that with any lens, only one point (well, plane) is really in focus in theory — everything even 1mm from that distance is out of focus. But the realities of image capture — not the least of which is the size of the photosites on your camera's sensor — mean that really a range on either side of that is actually in-focus. The size of that range depends on many factors — using a tighter aperture means that you've got a larger margin of error, and if you're targeting a smaller output size, a larger amount of blur will be too small to see.

The hyperfocal distance is the setting for any particular lens where the good-enough-focus area is maximized (and therefore it depends partly on your definition of "good enough").

vytas · 09-23-2008, 12:02 PM

If you want to have all the scene in focus, you need a P&S camera - these cameras have tiny sensors, they can have just everything in focus.

Lowell Goudge · 09-23-2008, 05:32 PM

Originally Posted by mattdm

The important thing to remember is that with any lens, only one point (well, plane) is really in focus in theory — everything even 1mm from that distance is out of focus. But the realities of image capture — not the least of which is the size of the photosites on your camera's sensor — mean that really a range on either side of that is actually in-focus. The size of that range depends on many factors — using a tighter aperture means that you've got a larger margin of error, and if you're targeting a smaller output size, a larger amount of blur will be too small to see.

The hyperfocal distance is the setting for any particular lens where the good-enough-focus area is maximized (and therefore it depends partly on your definition of "good enough").

I would agree, almost. It is really only 1 surface that is in focus, but most often it is spherical, not a plane. very few lenses have a flat focusing plane (macro's are the exception)

JonPB · 09-23-2008, 06:34 PM

Originally Posted by throndor

1- So there is no way to get things in focus from 1 inches to infinity? (i've seen some photos where they shot the beach boulders and the sea, both of which were pretty in focus?)

One option was mentioned--a wider lens creates a larger apparent depth of field--but there's another: move away from the subjects. Say you want the boulders and the sunset both in focus. To keep both subjects in focus and in the frame, you can either (a) be close to the boulder and use a wide lens with a very small aperture, or (b) be further away from the boulder, use a longer lens with a larger aperture.

To have a large depth of field--and thus a near hyperfocal distance--you want a small absolute aperture. Apertures are usually given in relative values with an "f" number: focal length divided by that number provides the absolute aperture. Compact digital cameras use small sensors, short focal lengths, and small absolute apertures...and have a very large depth of field as a result. Medium format cameras use long focal lengths and large absolute apertures, and have a narrow depth of field, to capture the exact same image. If you really want a camera to be in focus from a few inches to infinity, you want a very small absolute aperture--like with a pinhole camera.

Practically speaking, though, the best way is to zoom with your feet: rather than changing the camera to focus on the boulder and the sunset, change the relative location of the boulder by moving away from it and moving it into the camera's depth of field.

stevebrot · 09-23-2008, 07:11 PM

Here is a link to an online calculator that may be used to build a DOF table for just about any lens:

Julian's Lens Calculator

Steve

stevebrot · 09-23-2008, 07:19 PM

The OP mentioned photos where both a rock in the foreground and a larger feature some distance away would still be in focus. I posted regarding the use of a view camera, but it may not be clear that those types of pictures are almost always done using the tilt movement (sort of like a lensbaby, but much better).

Here is a link to a very good explanation within the Wikipedia article on view cameras:

View camera - Wikipedia, the free encyclopedia

The effect, when done well is quite striking. I have a coffee table with a picture featuring a small star fish a few inches from the lens rendered in the focal place as a large rock formation some distance away.

Very cool.

Steve