Depth of Field

The focal length of your lens plays a big part in determining the depth of field (DOF) for your images. Think of your lens strength as a limiting factor for your aperture capabilities. The higher the magnification factor, the smaller the depth of field will be, even with large F-Stop settings.

Depth of Field Progression for a 70-300mm Lens

• 70mm = largest DOF
  
• 100mm = large DOF
  
• 200mm = small DOF
  
• 300mm = smallest DOF

This effect is especially pronounced in macro photography where close proximity to the subject and high focal lengths result in depths of field that are sometimes less than an inch.