Effect of aperture on DOF for macrophotography
Using the Olympus ZD 50mm f/2.0 macro lens with 2x TC:
These photos were taken with an Olympus E510 with ZD 50mm f/2.0 macro lens coupled to a Olympus ZD EC-20 2x teleconverter and a Olympus Ring Flash, with manual focus at closest focus (ie. 1:1 macro). Full images with no in-camera or post-processing sharpening, just straight jpegs from the camera, resized in PS to 600 pixels wide and compressed for web display.
Aperture readings are those displayed in the camera and thus are the lens aperture multiplied by 2x to account for the EC-20 2x teleconverter.
At 1:1 macro
|f/4 - barely have 1mm depth of field when viewed at this
resolution - much less on large prints!
more exposed than the remainder - TTL auto-exposure used for all
|f/16 - even here, you only get about 4-5mm depth of field|
|f/22 - whilst you now get about 7mm depth of field, you are starting to lose resolution due to diffraction (see macro - aperture vs resolution)|
|f/32 - DOF benefits at a significant cost of loss of resolution due to diffraction.|
|f/45||oops forgot to do this one, but resolution due to diffraction is poor anyway at f/45 - I would not use it.|