Infinity & The Distance Scale

Which focus setting would I use to achieve maximum DOF, in this example, for 28mm?

Would I center the infinity marker on the white line like picture 1?:

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Second photo is the one, hyper focal focusing

Charles4400 wrote in post #2016035
Which focus setting would I use to achieve maximum DOF, in this example, for 28mm?

<SNIP>

Q1, Other than setting the infinity marker for DOF what other purpose would the distance scale serve for dslr's?

Q2, And with a lens without a distance scale, how would you focus for the maximum depth of field with the smallest aperature ?

Q3, BTW using the infinity marker is the most optimal way of focusing for the greatest DOF right?

Thanks!

Hi Charles4400,

A1, well the red text and markers are there so you can set the correct focus when shooting infrared.

A2, With dificulty, laser rangefinder, tape measure, guess.

A3, nope, use hyperfocal distance which allows you to find the optimal point of focus whilst using the lowest aperture. See here DOF Articles

DOF Calculator

Hope that helps

BearSummer

That all depends on how far you are from the subject...
There is no good setting it to infinity if you are only 5 metres away as the image would be blurred...

If you are using manual flash and have focused manually the markings will tell you how far away the subject is... This should help with calculating the power ratio of the flash...

DOF roughly extends 1/3 in front of the point of focus and 2/3 behind the point of focus so you would focus 1/3 of the way into the subject...

No... Focusing 1/3 of the way into a subject will maximise the DOF for any given f/ stop...

Thank you!
Very Informitive and much appreciated!

I just found this article Which is an intersting counter arguement to using the hyperfocal distance.

http://www.trenholm.or​g/hmmerk/DOFR.html

I think it can be summed up in two statements he makes:

“...What bothers me...is the old story about maximizing depth-of-field by focusing at the hyperfocal distance. If you follow that advice you will be guaranteed that scenes in the distance will never be resolved any better than mediocre. You will have sealed in that "minimum acceptable standard"...”

"...The general rule for scenic photographs, where one wishes to maximize the depth of field, is as follows. Set the focus at the distance of the most distant object. Then set the lens opening to the size of the smallest object to be resolved in the foreground. No calculations needed!..."

One add'l piece, I recently found this DOF calculator, pCAM, which I feel is the finest one I found... http://www.davideubank​.com/

I miss the old school DoF/distance scales. You could actually SEE what your DoF is for a given aperture (at a particular focal length, if it's a zoom).

“...What bothers me...is the old story about maximizing depth-of-field by focusing at the hyperfocal distance. If you follow that advice you will be guaranteed that scenes in the distance will never be resolved any better than mediocre. You will have sealed in that "minimum acceptable standard"...”
"...The general rule for scenic photographs, where one wishes to maximize the depth of field, is as follows. Set the focus at the distance of the most distant object. Then set the lens opening to the size of the smallest object to be resolved in the foreground. No calculations needed!..."


A nice argument ,but his solution seems to be based on accepting that all foreground elements will be compromised instead
.....at least i THINK that's what he's implying - that second last sentence makes absolutally ZERO sense at all?How does one 'set the lens opening to the size of the smallest object ' ??

Just checked out that link.
What he's on about does seem to make sense -but it's FAR from easy !!!

ron chappel wrote in post #2021723
Just checked out that link.
What he's on about does seem to make sense -but it's FAR from easy !!!

If you have a Palm, try the pCAM DOF calculator. I found it help me understand the concept better....it does take a little playing around with it to get fully "conversant" with it. I also plug in actual sizes and CoC values for the 5D (and 20D, Nikon 200, etc. to use with my friends).

John

Double Negative wrote in post #2021505
I miss the old school DoF/distance scales. You could actually SEE what your DoF is for a given aperture (at a particular focal length, if it's a zoom).

Some still do - mostly primes, and it seems that the shorter ones have a wider scale with which to use. Note how the 24/1.4L has the appropriate markings, though the scale doesn't present the precision of the older lenses either:

Thanks, Tom for showing that.

You're right, obviously the wider angle lenses will have more of a scale simply because of the greater (and more spread out) DoF. Depends on the lens, etc. too. I guess I was referring to the older lenses that had much more detail, like you said - especially FD over EF. Part of it is due to the lens design and the way the distance scale is implemented between the two.

the 85/1.2 I retains some decent spacing between the DOF marks, due to the longer throw of the focus ring. But you're right, in many cases, older lenses did give better detail. I had an old FD-mount Tamron 28-80 zoom that had the DOF marks set up so that as you zoomed (push-pull), the spacing between the lines would gradually get wider or closer together. IF I still had the lens, I'd take a picture (I literally wore it out).

I haven't seen a modern zoom with DOF markings on it. Just primes, and not all of them.

I'll snap a picture of my ol' FD 70-210mm f/4... It's a push/pull design and has the marks you're talking about. It's pretty interesting and definitely useful.

There's always the depth-of-field preview!