How to focus: Let's say I am using f/11 on my DSLR. With my 35mm 1.8 prime lens. If I'm shooting on the street everything several feet in front of me to infinity, do I still need to...

rlansing Loc: Boston

Let's say I am using f/11 on my DSLR. With my 35mm 1.8 prime lens. If I'm shooting on the street everything several feet in front of me to infinity, do I still need to focus the lens with every shot as I move along? Because it seems to me that everything should be sharp within a certain distance with a stopped down aperture such as f/11 or more? And how does this work with a zoom lens at a constant aperture? Thanks

Urban Landscape Loc: Basement of the Internet

Set it to f64 and be there.

cygone Loc: Boston

What will f64 do? What kind of focusing distance will I get with f11? Thanks

RWR Loc: La Mesa, CA

rlansing wrote:

Let's say I am using f/11 on my DSLR. With my 35mm 1.8 prime lens. If I'm shooting on the street everything several feet in front of me to infinity, do I still need to focus the lens with every shot as I move along? Because it seems to me that everything should be sharp within a certain distance with a stopped down aperture such as f/11 or more? And how does this work with a zoom lens at a constant aperture? Thanks

With focus set at 3m, at f/11 you will be in focus from 1.659 m-15.638m. Set at infinity, you will be in focus from 3.712m to infinity. (Tokina chart). Set it and forget it. :)

Edit: This is with a 35mm lens. Depth of field with other focal lengths will vary - increasing with shorter and decreasing with longer focal lengths.

Uuglypher Loc: South Dakota (East River)

Urban Landscape wrote:

Set it to f64 and be there.

Which harks back to to the axiomatic "f8 and be there" when a Leica with a 28mm or a Speed Graphic with its comparable wide-angle lens had adequate DOF at f8 for most any street exigencies and seat-of-the-pants photojournalism.
(often attributed, but apocryphally, to Arthur Felig - "Weegee" - the renouned, colorful, self-promoting photojournalist/NYC Crime photographer of the 1940s and '50s).

Dave in SD

Photocraig

You broke the code on how the old "Brownie" cameras worked. Their focal lengths were middle wide like a 35 or 40mm on our 35mm or APS-C's. Then all you did was, truly point and shoot. The Drugstore one time film cameras still work that way. So, f11 @ 30-40mm would do the job. The fuzziness you'll see will be far more from camera shake that from focus. And, of course you can fix that with a faster shutter and higher ISO.

davidheald1942 Loc: Mars (the planet)

Some lenses I've had over the years were not very
sharp stoped all the way down. Your 35mm should
have about f/16 stopped all the down
(probably not
f/64 lol). Just like most lenses aren't sharp when
opened all the way open, most aren't sharp if stopped all the
way down. You should be able to read the scale on
your lens and set it to be in focus from about 8-10 feet
and get pretty good sharpness to infinity.
I'd have to be there to show you exactly how to go about it.
Someone with a better brain than mine will chime in
here shortly and have a complete & more accurate
answer.
Have a blessed day.
ronny

rlansing Loc: Boston

Thanks for the replies

St3v3M Loc: 35,000 feet

rlansing wrote:

Let's say I am using f/11 on my DSLR. With my 35mm 1.8 prime lens. If I'm shooting on the street everything several feet in front of me to infinity, do I still need to focus the lens with every shot as I move along? ...

Place the lens on manual focus and aim with the same distance in front of you. Essentially, you always look XX feet ahead.

A Depth of Field Calculator may help http://www.dofmaster.com/dofjs.html

rlansing wrote:

... And how does this work with a zoom lens at a constant aperture? Thanks

This may help http://www.youtube.com/watch?v=1oVmvlL1FBA

rlansing Loc: Boston

Does this mean I don't have to press the shutter half way down? Thanks

Photocraig

With a heavy emphasis on BEING THERE! You miss ALL the shots you don't take---per Mr. Gretzky.

amehta Loc: Boston

rlansing wrote:

Let's say I am using f/11 on my DSLR. With my 35mm 1.8 prime lens. If I'm shooting on the street everything several feet in front of me to infinity, do I still need to focus the lens with every shot as I move along? Because it seems to me that everything should be sharp within a certain distance with a stopped down aperture such as f/11 or more? And how does this work with a zoom lens at a constant aperture? Thanks

Only one distance is "in focus", all the rest are out of focus. The main question is what distances are perceptibly out of focus? I prefer to make sure my primary subject is in focus, so I do focus each time, unless I know that I and the subject have not moved.

Nightsky Loc: Augusta, GA USA

rlansing wrote:

Does this mean I don't have to press the shutter half way down? Thanks

If your camera has the option you can switch to back button focus (BBF) so the focus does not change when depressing the shutter release button. It's a little bit strange at first, but it works great. That way you set it once, and shoot away.

OR

Check out this link on hyperfocal distance

http://digital-photography-school.com/landscape-photography-hyperfocal-distance/

You can also search it on the hog - there have been many discussion threads on it.

rlansing Loc: Boston

Thanks for all the replys

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

rlansing wrote:

Let's say I am using f/11 on my DSLR. With my 35mm 1.8 prime lens. If I'm shooting on the street everything several feet in front of me to infinity, do I still need to focus the lens with every shot as I move along? Because it seems to me that everything should be sharp within a certain distance with a stopped down aperture such as f/11 or more? And how does this work with a zoom lens at a constant aperture? Thanks

You don't indicate what camera you are using. Hyperfocal distance on a cropped sensor at F11, 35mm, will be a little over 18 ft, and about 12 ft on a full frame.

Your range of "acceptable" focus will be 9 ft and 6 ft to infinity, respectively.

If clear, sharp results are desired, stay below F11 since most cameras will begin to display diffraction-limited loss of sharpness at smaller openings.

With wide angle lenses, the zone of acceptable sharpness will be split roughly 1/3 in front and 2/3 behind the subject. With longer lenses the zone approaches 50/50.

As as been suggested, turn off AF Activation (in Nikon), which will not force the camera to focus each time the shutter is pressed, or simply turn off autofocus on the lens.