Jump to content

hyperfocal without distance scale


mo_zhang

Recommended Posts

I have one of the cheap zooms. At the moment, that's all I can

afford, and I'd like to use it dispite of the draw backs.

 

How do I focus to the hyperfocal distance without the DoF marks?

Should I estimate distance, or bring a tape measure around me all

the time? If I estimate - how does the DoF change if I'm not focused

on the EXACT hyperfocal distance?

 

thanks

Link to comment
Share on other sites

Without a distance scale, the tape measure isn't going to help without a lot of leg work. For hyperfocal settings to work, you need to know the distance the lens is focused at, and the distance of the near & far objects.

 

You can do it of course. You measure (or estimate) the distances of the subjects and then consult your hyperfocal chart (You do carry this with you don't you?), set your aperture and then carefully measure to the hyperfocal distance, mark it, and focus right there.

 

Kind of clumsy in this modern age.

 

Anyway, you don't mention what camera body you are working with. All Canon EOS cameras have some form of a hyperfocal calculation feature designed into them. Some of them have a DEP feature (Look at the Command Dial on top of the camera) where you AF on the far, and then the near subject and then take the picture. The camera then calculates the different distances, selects the appropriate aperture, and adjusts the focus to the hyperfocal distance, before taking the picture.

 

Lower end EOS cameas use an A-DEP function where it does the above in one step, but only if you have an AF point on each of the distances you want to keep in focus.

Link to comment
Share on other sites

Even if a lens has DoF or distance marks I find them to be less than useful most of the time. I have been using a <a href="http://www.fotosharp.com">FotoSharp</a> DoF card with pretty good results (I calculate using one extra stop for insurance) in my landscape shooting. Of course the hard part is guesstimating the distances, but that has mostly sorted itself out with experiance - I am thinking of buying a <a href="http://www.strait-line.com/irwin/consumer/straitline/jhtml/product_detail_laserTape.jhtml">laser measure</a>, but I am not sure how accurate they would be in the 'softer' environment of the outdoors. <p>

 

--

Link to comment
Share on other sites

Lars is right.

 

What I do for landscapes when I want fullest dof is:

 

use A-DEP for closest/farthest

 

set the lens to manual focus and leave it there, you have hyperfocal set

 

THEN, in manual metering mode, I do my metering based on that f/stop OR ONE HIGHER /SMALLER, NOT ONE LOWER/LARGER

 

THEN, if my far focus was on infinity, I might back the focus to a closer setting, but VERY little

 

lastly, I use my dof indicator for my closest point, to make sure I haven't gotten things backward, as I am wont to do

Link to comment
Share on other sites

Somebody correct me if I am wrong, but I thought the definition of the hyperfocal (and note hyper in the word) distance is the distance at which the lens is focused which will yield the maximum dof at a given f-stop. And by definition this means the far distance MUST be infinity (or rather the infinity mark on the lens).

 

If one is going to use the DEP mode in order to have the camera actually set the lens to the hyperfocal distance which corresponds to the set f-stop, that means the infinity mark must be the second focus point.

Link to comment
Share on other sites

Mo:

<p>

Here is a <a href="http://jimdoty.com/Tips/Depth_of_Field/Hyperfocal_Distance/hyperfocal_distance.html"> Hyperfocal Distance Chart</a>.

<p>

The chart is calculated for an 11x16 inch enlargment on 35mm film. The math behind the chart is <a href="http://jimdoty.com/Tips/Depth_of_Field/depth_of_field.html"> here</a>, along with additional information.

<p>

If you have a PDA that uses the Palm operating system, there is a program that computes depth of field for you. Info on this program is <a href="http://jimdoty.com/Tips/Depth_of_Field/Palm_Visor_DOF/palm_visor_dof.html"> here</a>.

<p>

There are several commercial depth of field cards and charts available to guide you in your aperture and distance settings for a given focal length.

<p>

Jim

Link to comment
Share on other sites

Jim, there's only one hyperfocal distance per aperture setting. Hyperfocal distance is

the focus setting that, for a given aperture, maintains sharpness from a given point to

infinity. No distance calculations are necessary - at a given aperture, the object either

falls within the hyperfocal range or not.

 

With the 50mm f/1.8 II (no distance window) all I needed to do was figure out the

hyperfocal distance for f/8, focus there, and then use a razor to score the lens and

ring. Now I know where to go for hyperfocal photos at f/8.

Link to comment
Share on other sites

<I>"there's only one hyperfocal distance per aperture setting"</I><P>That's not really true, it depends on the size you choose for the circle of confusion... which depends on how much you want to enlarge the photo and sharp you want it.<P>Scoring the lens (or otherwise marking it) is a great idea though! Why didn't I think of that?<p>Karl Lehmann <a href="http://www.lostworldarts.com/new_page_3.htm">Lost World

Arts</a>

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...