focusing question

[shaaktiman]

Does anyone know the difference between zone and hyperfocal systems for focusing?

[Kris]

Zone focusing? I know zone system used for measuring exposure but not zone focusing. Oh well, i guess i always learn something new everyday.



I'm eager to read explanation of zone focusing from other true photogs we have here at RFF.

[back alley]

if i have this right, zone focussing is found on simpler cameras, uually the camera has symbols on it like a person, and a mountain to show near and far focussing.
hyperfocal distance is setting a a specific aperture and looking to see how much will be in focus by feet. for example setting the aperture to f11 and having the focus be 'correct' from say 3 feet to 40 feet.

here's a site that will explain it better.

hyperfocal

joe

[pvdhaar]

Anyone's guess is as good as mine, so here goes:

Hyperfocal focussing is setting focus and aperture in such a way that subjects at infinity fall just inside depth of field at the far side. Main application: maximise the extent of depth of field for landscapes.

Zone focussing is having set focus and aperture in such a way
that as an object moves inside the depth of field, an acceptably sharp image results. It does not necessarily include infinity. Main application: documentary/street photography.

Basically they're the same and the only true differentiator is whether infinity is at the far side of depth of field.

[Doug]

Peter's explanation is the same as my understanding of the distinction. I believe Hyperfocal distance is defined as that focus distance at which infinity is at the far extent of depth of field. The zone or range of acceptable focus then extends from infinity to the near extent of DOF.

But I think Joe is right too on the zone focus, as those simple cameras with the focus symbols don't include a DOF scale to give a clear idea of the extent of the DOF.

Another term is "scale" focus, which I think is just focusing by setting the lens to the subject distance as marked on the scale... Implied is a guessed/estimated distance (relying somewhat on DOF), though I suppose it would also include distances measured by tape measure, knotted string, or accessory rangefinder!

[Laika]

Peter's explanation is how I've always understood the two.

Zone has a minimum and maximum distance of focus... A zone that is in focus

Hyperfocal includes infinity at one end and the minimum distance is depending on the aperture/focal length used.

[GeneW]

Speaking of Zone focusing, when I was a wee tad my friend's mom had a Kodak Pony II 35mm camera when everyone else was using Brownies. I can still remember being fascinated by its looks and the zone focusing symbols on the top. Any of you have one of these in your collection?

Gene

[Scarpia]

I have three ca. 1962 Agfas that I bought in Germany when once I was young and they were new. They are an Isola 6x6, an Isoly 4x4 that uses 120 film and a 35mm Silette. They all use this focusing system of symbols with a very few meter numbers in between the symbols. I used the Silette recently with excellent results considering the lens (f2.8 45mm Agnar) is a triplet.
Kurt M.

[pshinkaw]

I have an old 135 Pony (I think they were also made for 828 Bantam film, but I have never used this one. The Agfa Optima Sensor series used zone focus symbols on top and matched them with metric and English markings on the bottom. On this camera the detents for mountains, group and portrait are the same as infinity, 15 feet and 5 feet.

-Paul

[Scarpia]

Same as mine , Paul. They seem to work out OK.
Kurt M.

[Doug]

Paul and Gene, I too recall the Kodak Pony, from trying to sell them at the camera shop where I worked in the mid-60's. Grey plastic top cover, and the lens was on a metal housing that popped out to taking position on the strength of an internal coil spring.

I don't recall if the lens varied between the two, but there were indeed both 135 (35mm) and 828 Bantam versions. I also recall a sizable pointy projection from the lens that I think was a flash connector. Zone/scale focusing for sure!

I should have taken one of these out for a shooting test, as I did other used cameras. But it didn't inspire as did the Nikon S2/S3, Canon Vt, Leicas, or various Zeiss machinery. Under pressure from the shop owner, however, I did take out various Instamatics, including both versions of the Yashica EZ-Matic. More scale focus, but surprisingly good lenses...

[Marc Jutras]

There's a very nice site that provides a DOF calculator. I have the PDA version in my Palm and I find it useful, especially if I want to calculate hyperfocal. Note that it's more useful with modern SLR lenses that have no DOF markings. My CV lenses have the markings and they help a lot.

http://dfleming.ameranet.com/

[LionFlyer]

I have a PDA with a DOF program on it as well. Can do several formats too. I have been playing around with using that calculator to help me mark a paper sticker applied to the lens barrel for depth of field. Trouble so far has been estimating just where some of those distance values which fall between the scale markings would be. Plotting out the several points does result in a scale which looks credable though.

[Todd.Hanz]

This article compares Zone Focusing and Hyperfocal, enjoy:
http://www.fortunecity.com/marina/ma.../focusing.html

Todd

[back alley]

that article looks pretty good. will have to go back and give it a better read.

thanks,
joe

[craygc]

Hyperfocal distance for a particular apeture is defined at both ends. As everyone has indicated, infinity is the far end but it actually represents a single focus distance (the hyperfocal distance) such that (for you chosen CoC) there is acceptable DoF between half the hyperfocal distance and infinity.

The Contax G series relies on it a lot in manual focus mode as there are no DoF markings on the lens. The same table as is in the manual is given here:
http://www.contaxg.com/contaxuser/tables.html#hyper


regards
Craig / Beijing