Hyperfocal focus tricksgreenspun.com : LUSENET : Large format photography : One Thread
Okay, I fully understand and can calculate what the hyperfocal distances are for my various lenses. Does anyone have a quick convenient way to use the information in a field setting? I mean sometimes its just hard to pace off the 83 foot distance to focus, especially if you're taking photos of the ocean, for instance. Do you have a cloth tailor's tape or something with the lensboard to film distance marked off for various lens and aperture settings? I could really use a nice quick way of doing this, especially for the panoramic shots, where the edges tend to go soft if you don't 'focus in' to the hyperfocal distance. I'm just interested in hearing if there is some splendidly simple idea to accomplish this. Thanks
-- clay harmon (firstname.lastname@example.org), April 22, 2002
You are better off using front or rear tilt. But if you insist, the easiest way is to get an optical rangefinder like they used back in the 1950s. Use the rangefinder to find something at the distance you want, and then focus your camera on that point.
-- Steve Gangi (email@example.com), April 22, 2002.
I know that front tilt is useful, and I use it all the time. But I am shooting 7x17, and with some subjects, you must use the hyperfocal distance to focus in order to get the sharpest image on either side of the negative. Front swing will work only if the plane of the subject is receding one direction or the other across the negative. But the rangefinder is mabe a way of finding the something to focus on at the hyperfocal distance.
-- Clay Harmon (firstname.lastname@example.org), April 23, 2002.
Why not pace off the distance in a controlled environment, place an object, and then go back, focus, and mark the distance on your rail or focus scale or whatever? You'd only have to do it once.
-- Noshir Patel (email@example.com), April 23, 2002.
Pacing it off may be the way to go. That's what I was going to do anyway, but I was wondering if there was some clever trick that someone had come up with to avoid this. It really isn't that big a deal, it'll just take an hour or so to go through the lens and aperture combinations that I normally use.
-- clay harmon (firstname.lastname@example.org), April 23, 2002.
There is an article on the Large Format Home page for building a depth of field calculator. It can take the form of a circular ring attaced to the focus drive (a la Sinar) or as a flat card if the circular approach will not work for your camera.
The article helps you figure out what circle of confusion you want to use for your particular format.
These calcularots essentially help you to set your focus at the hyperfocal distance not by measuring, but but focusing on the near and far planes you want in focus.
There is a recent post on this forum concerning the availabilty of the Large Format Page. Read that for the latest info.
-- Jerry Flynn (email@example.com), April 23, 2002.
A simple solution would be to focus a 35mm camera on the subject, and then read the distance off the lens. A more "techno" solution might be to buy a laser range finder (golf shops, radio shack, and purveyors of survey instruments have these).
-- Dave Brown (firstname.lastname@example.org), April 23, 2002.
The quickest solution from my experience carry your cheat sheet of DOF in your pocket, use a laser rangefinder (I prefer DME) to determine your near and far, check your chart and find the distance you need to focus on, of course it does not need to be the hyperfocal distance.
Now, (I am reiterating from above) the easiest solution is, use the laser rangefinder to find something at that distance and focus on it. If that's not possible, as in your ocean example, then spin the camera around on the tripod head and find something else at the correct distance and focus on it, spin back and recompose. If that's not possible, you can always do the entire process by standard measurements....
First focus all your lenses at infinity. Lets say you are using 600mm, you focus at infinity, then measure between the two standards, make it some place easy to measure, I use the outsides of each standard. Lets say it measures 610mm. So you record a +10mm offset for that lens onto your cheat sheet, this only needs to be done once for each lens. This accommodates the issue with the standards positioning and they lens nodal point. (just be sure you always re measure at these exact spots)
Now, you calculate what the bellows extension should be to focus at X distance, this too can be on a cheat sheet, or use a programmable calculator. Just add 10 mm to this value, seperate the standards till you hit this combined measurement and your done.
This technique is also quite useful when shooting in very low light and you can't see through the gg well enough. Hope this helps.
-- Bill Glickman (email@example.com), April 24, 2002.
To mark a hyperfocal scale on your camera (use masking tape) for whatever lens, take a friend to a football field and have him stand at the hash marks, focus and mark. I have a cheat sheet that gives me infinity as well as HF distances at the apertures I normally shoot. Using a 50's model rangefinder which you can probably get for $30, sight your subject, check you chart, and it will tell you what range you are in for what aperture. You can set the rangefinder to near focus and then far focus distance markings, and sight with the rangefinder till the split focusing spot is even giving you a sighting as to the focus field.
-- Wayne Crider (firstname.lastname@example.org), April 24, 2002.