Depth of Field

Control of depth of field is a fundamental skill in photography.  No matter what your skill level is, there is always more to learn and plenty to forget. 

This week we will explore depth of field.  Do a bit of practice and hone up our skills. 

Find three small objects.  Three cups would work well.  Place them on your dinning room table or study desk.  One near you, one in the middle and one on the other side. 

Now take the following photographs: 

  1.  One with each of the objects in focus ensuring that the other two are out of focus.  Three photographs here.
  2. One with two of the objects in focus and with one object out of focus.  Repeat with a different object out of focus. The middle object will be sharp in both photographs, as it would be impossible to have it soft and the other two in focus.  
  3. A photograph with all three objects in focus. 

What did you need to do to achieve these six photographs?  Did you change the aperture?  Did you have to move the objects?  Did you need to change the focal length of the lens or your viewpoint? 

Here are my personal rules and approaches: 

  1. Large hole in the lens = small aperture number = small depth of field 
  2. Small hole in the lens = large aperture number = large depth of field 
  3. Focus on the most important subject
  4. Focus at the important object in the front
  5. Focus at a third of the way on the picture plane.   This is the most misunderstood rough rule. Because people interpret it as a third of the way into the subject plane.
  6. If it is important use depth of field tables or an app.  PhotoPills is my favourite go to photography app for nearly everything.  For years I carried a laminated depth of field table for each view camera lens I carried.
  7. Wide angle lens have more depth of field than telephoto ones
  8. Worrying about circles of confusion and defraction is confusing and unless you print huge prints is not worth worrying about.  If you do choose to worry about it, shoot at f5.6 and still don’t worry, just enjoy the constraint of working at the sharpest aperture. (Yes each lens has a different sharpest aperture, but in 95% of lenses it is f5.6 - if in doubt look it up)

When I photograph groups of people I use the app and a tape measure.  I mark the exact spots on the floor with tape.  I put a chair or my trusty assistant on the point where I need to focus, focus the camera and remove them before the people arrive.  Focusing and exposure all done in advance, makes it easier to concentrate on posing and composition.

Here are some tutorials for more information. They are presented in order of difficulty.  The hardest being last.  Only go as far as you need too.  

 https://www.photographymad.com/pages/view/depth-of-field-explained

 https://www.cambridgeincolour.com/tutorials/depth-of-field.htm

 http://www.normankoren.com/Tutorials/MTF6.html

Lastly 

Now take two photographs to post and discuss.  Make sure you acurately describe where you focused, which camera / lens combination and the f stop you used, when you post your photographs.

Take a photograph with a great depth of field that pleases you. Then take a photograph of something different, if you like,  with limited depth of field.  Make sure they are both resolved and finished.   

Post these last two photographs.  You can post the ones with the three objects too if you like. I am sure others will find them helpful. 

South African Sands.  Olympus Em1 mk2 Olympus 25 mm f1.2 Lens.  F1.8 @ 1/2000 second ISO 200   Focused 1/4 way up the photograph - not a 1/4 way into the scene.   

South African Sands.  Olympus Em1 mk2 Olympus 25 mm f1.2 Lens.  F1.8 @ 1/2000 second ISO 200   Focused 1/4 way up the photograph - not a 1/4 way into the scene.

 

Myall Lakes Sands.  Olympus Em1.  Voigtlander 25mm f0.95 Lens.   F8 @ 1/650    Focused on the sand 1/3 division between the bottom of the frame and the sky.

Myall Lakes Sands.  Olympus Em1.  Voigtlander 25mm f0.95 Lens.   F8 @ 1/650    Focused on the sand 1/3 division between the bottom of the frame and the sky.

 

 More people are signing up.  It is so great to see everyone’s photographs and comments each exercise.   A fantastic supportive community is developing.  Most of you are past students, which is just lovely. Please feel free to invite your friends and photography colleagues.   Thank you for making this so interactive and interesting.