Increasing depth of field (DOF)

Hyperfocal distance is not something that trips off the tongue in this modern age of auto focus. In fact digital camera lenses do not have the facility to take advantage of this compositional tool. You just have to compare today’s lens with yesterdays they don't have aperture settings and therefore you can not play with hyperfocal distance settings.

So what is Hyperfocal distance?

When a lens is set to infinity, the depth of field (D.O.F) closest to the camera is known as the Hyperfocal distance for that aperture. If you have an older lens its barrel will be marked with these distances.

How to change the Hyperfocal distance.

Set the lens focus to infinity, and then read the lower mark for whatever aperture you have set. If you then refocus the lens to the lower mark known as the optimum distance you will increase your depth of field by fifty per cent of the optimum.

For example:

This was made using a
 telephoto lens at close distance.
 The use of hyperfocal distance has
 pulled the area of sharp focus
to the front of the ball.

I have used an old 50mm Nikon lens (pictured) to show how it works. I have set the focus to infinity and the aperture to F16. The good thing about this lens is that it shows the upper and lower limits of each aperture with lines on the lens barrel. Looking to the right (marked A) you can see that the last line on the lens barrel is opposite the five meter mark (about fifteen feet). By resetting the focus to optimum in this case five (A). Then look at the lower limit (marked B) for F16, it is about two and a half meters (eight and half feet). The resetting will extend the overall sharpness of the picture by an extra two and a half meters which is 50 percent of the optimum.

The longer the lens the greater the increase is. For argument, an 80 mm lens with an aperture of F22 set, would have a depth of field from 2.8 meters all the way to infinity when optimum focus is used. Instead of 5.6 meters to infinity.

If  hyperfocal distance had been
used with this picture the
 front post would be sharp.
 

In some cases where you do not have aperture lines on the barrel of the lens some cameras and lenses have a shut down button. This allows you to see before you press the shutter where the hyperfocal distance ends. So you can adjust it if needs be.

Being able to increase the depth of field (D.O.F) can be very useful when using medium and long telephoto lenses for subjects close to the lens, allowing narrow fields of sharpness to be moved. This makes sure the front of the item is in focus.

Street Photography part 3

 

It was a wise decision to use the look down viewfinder. It has aloud me
to make some extreme angle and candid images without to much fuss. If
someone catches my eye after making an image of them I always offer a card
so they can get in touch if they would like a copy of the image.

You get some looks when people suddenly realized that you may have included
them in a picture and or have a camera in your hand. You become a demon
that needs a scowl to keep you at bay so they can carry on their way with
there soul intact . I'm pleased to say there are others only to happy to chat.
But here is the rub I do not always print my images to include all the detail and
therefore they may only be a shadow.

 

I have found that the longevety of a project can be dependent on the kit you
use. Which bring me onto the camera system this can help or hinder the
possiblities in some cases. I know some people think I'm cracked to be lugging
a round a Bronica SQAi and that it is film based. You have to remember that it
is a pro set up meaning by changing the viewfinder I have a new angle of view
and therefore a different composition with the same lens, film combination. By
doing this it keeps the possibilities fresh. Likewise a change of lens would do
the same along with a change of film format from 120 to say 35mm.

 

The Bronicas look down viewfinder shows the picture back to front where left is
right, right is left. This can change the look of the compostion making it or
bracking it. It can also be frustrating when it comes to deal with a fast moving
street scene. This is where familatery with the way the camera works comes
into play.

 There are no rules to street photograph you do not have to use the same kit all
the time as hinted at above it is good to mix it up by doing so it keeps it fresh.
Oh! And Keep an open mind.

 

 Time moves on and so do I with camera in hand scouting for the next picture.

 

 

 

Techinal Data:

Monochrome images scanned from prints using flat bed scanner.  Ilford multigrade RC paper.

Pictures and article are the copyright of Mitch Fusco 2023.

Here are links to Preivious posts  on Street photography project if you have missed them.

Street part 2 

Street part 1