Hyperfocal Distance Calculation: For years I've frequently used hyperfocal distance settings, particularly in landscape work. In that I pretty much know the settings to use on my most...

windshoppe Loc: Arizona

For years I've frequently used hyperfocal distance settings, particularly in landscape work. In that I pretty much know the settings to use on my most frequently used lenses and f stops I rarely have to resort to my calculator. When I do, however, I'm asked to input "subject distance" as one of the factors. What I don't understand is how the subject distance affects the hyperfocal distance. For example, if I know that at f/22 with my camera body and lens I need to manually focus at 3 feet to achieve hyperfocal distance, thus giving me acceptable focus from approximately 1.5 ft to infinity, what is the difference if my subject is at 20 or 100 feet? Any help to clear up my confusion will be most appreciated.

emmons267 Loc: Arizona, Valley of the Sun

windshoppe wrote:

For years I've frequently used hyperfocal distance... (show quote)

Subject distance isn't required to calculate HF distance. Some of the calculators also are calculating DOF and the subject distance is needed for that. But, notice that as you only change the subject distance, the HF stays the same.

imagemeister Loc: mid east Florida

To my way of thinking, the subject disance would have to be understood to be the furthest distance that you want in focus .....these things used to be engraved on lens barrels - back in the day. The subject distance is a very important ingredient in the hyperfocal equasion.

ecobin Loc: Paoli, PA

mfeveland wrote:

Subject distance isn't required to calculate HF distance. Some of the calculators also are calculating DOF and the subject distance is needed for that. But, notice that as you only change the subject distance, the HF stays the same.

:thumbup: Exactly correct.

joer Loc: Colorado/Illinois

windshoppe wrote:

For years I've frequently used hyperfocal distance... (show quote)

http://www.dofmaster.com/dofjs.html

windshoppe Loc: Arizona

mfeveland wrote:

Subject distance isn't required to calculate HF distance. Some of the calculators also are calculating DOF and the subject distance is needed for that. But, notice that as you only change the subject distance, the HF stays the same.

Ah, NOW it makes sense. Thank you!

MagicMark

imagemeister wrote:

.....these things used to be engraved on lens barrels - back in the day.

Amen.

LoneRangeFinder Loc: Left field

imagemeister wrote:

To my way of thinking, the subject disance would have to be understood to be the furthest distance that you want in focus .....these things used to be engraved on lens barrels - back in the day. The subject distance is a very important ingredient in the hyperfocal equasion.

Concur. I use a range finder. I must make a determination of what I want in focus. I don't understand how distance would be irrelevant. In my "range-finder world" it is critical. The "science" of this does not change.

johneccles Loc: Leyland UK

I have a small chart that fits into a credit card slot in my wallet, I very rarely use it now as I find that I can set my camera hfd or dof without using any refernce charts, by manually adjusting the focus point to the correct position in the photo.

charles brown Loc: Tennesse

There is a great smartphone app called simpleDof. Will calculate HD as well as doc. Easy to use.

selmslie Loc: Fernandina Beach, FL, USA

windshoppe wrote:

For years I've frequently used hyperfocal distance settings....

You should use hyperfocal distance calculations conservatively. Even if the calculators tell you that your image will be "in focus" from x feet to infinity, for a given hyperfocal distance, it will really be critically in focus at the hyperfocal distance. Focus will gradually degrade in either direction.

To be safe, it is best to calculate the hyperfocal distance at, for example f/5.6, and then select a smaller aperture like f/8 or f/11 for the photograph.

LoneRangeFinder Loc: Left field

selmslie wrote:

You should use hyperfocal distance calculations conservatively. Even if the calculators tell you that your image will be "in focus" from x feet to infinity, for a given hyperfocal distance, it will really be critically in focus at the hyperfocal distance. Focus will gradually degrade in either direction.

To be safe, it is best to calculate the hyperfocal distance at, for example f/5.6, and then select a smaller aperture like f/8 or f/11 for the photograph.

And then get the other kind of "range finder"-- the one used for golf.

;-)

Peter Boyd Loc: Blyth nr. Newcastle U.K.

imagemeister wrote:

To my way of thinking, the subject disance would have to be understood to be the furthest distance that you want in focus .....these things used to be engraved on lens barrels - back in the day. The subject distance is a very important ingredient in the hyperfocal equasion.

No it's not, you only need to know the hyperfocal distance for a given lens at a given aperture. You then focus at that distance and you are in focus from half the hyperfocal distance to infinity, so unless your subject is closer than half the hyperfocal distance you don't have a problem.

imagemeister Loc: mid east Florida

So, then it is understood that hyperfocal distance ALWAYS refers to infinity as the far distance ! ? That may be the technical definition ( not sure) - but not to my way of thinking ! ALSO, hyperfocal calculators as well as DOF scales are based on what the originator considers "in focus" - this in focus condition is quite a subjective subject - and is technically based on the size of the circles of confusion. Most GOOD DOF tables/calculators will specify the size of the circle of confusion used in their calculations.

windshoppe Loc: Arizona

Peter Boyd wrote:

No it's not, you only need to know the hyperfocal distance for a given lens at a given aperture. You then focus at that distance and you are in focus from half the hyperfocal distance to infinity, so unless your subject is closer than half the hyperfocal distance you don't have a problem.

That's always been my understanding also and results over time seem to support the concept.