This section of the website deals with technical aspects of photography,
such as Depth of Field, Lens Aberrations, Lens Testing, Hyperfocal Distance.
These apply equally to both digital and film based photography.
- • Focus and Recompose
- If you focus and then recompose, how much focusing error do you get?
- • Optical Illusions
- You just can't trust what your eyes tell you!
- • Diffraction and Image Sharpness
- What's the smallest aperture that still gives sharp images?
- • UV filters
- What do they do and how effective are they?
- • Measuring Focal Length
- Two techniques for measuring the true focal length of a lens
- • Field of View
- Field of view calcualtions for rectilinear and fisheye lenses
- • Depth of Field and Digital
- Effects of small digital sensors on DOF
- • MTF and SQF Explained
- Modulation Transfer and Subjective Quality Functions
- • Mutifunction Optical Calculator
- Depth of field, hyperfocal distance and more
- • Optical Blur Calculator
- Similar to the multifunction optical calculator, but this one also calculates just how blurred an object will be at given distances from the focal point.
- • Basic optics primer
- astigmatism, coma, spherical aberration - find out what they mean
- • Simple lens testing at home
- test your lenses without an optics lab
- • Why you can't trust lens tests
- other's opinions are fine, but only yours matter
- • Aerial image resolution lens tests
- a simple test which is easily (and often!) misinterpreted
- • Really Right Stuff - but really wrong optics
- potentially misleading information from RRS
- • Hyperfocal distance [HFD]
- What is it? Table of values for commonly used lenses and apertures
- • Depth of Field Calculator
- What is depth of field? Online web based DOF calculator
- • Sharpness at the HFD limits
- Defocus MTF calculations of DOF are not the same as the simple approximation