Jon Tarrant

Latest posts

Example image captured using the Samsung 85mm f/1.4 lens, exhibiting excellent sharpness.

Having looked at resolution figures quoted in line-pairs-per-millimetre and in cycles-per-pixel attention now turns to lines-per-picture, which is a measure that defines the maximum number of picture lines and therefore indicates the amount of detail that any picture can contain.

Read full post

Measuring lens resolution

MTF graph of Nikkor AF-S 85mm f/1.8 prime lens on Nikon D700 full-frame camera body

Lens resolution figures have long been stated in line-pairs per millimetre but in the digital arena it is common to use cycles per pixel: what is the difference and how are these two resolution metrics related to each other?

Read full post

Compact System Cameras

Two pictures showing correct and incorrect focussing priorities (AF).

Compact System Cameras are, in many ways, the best of both worlds; they and small and yet also very versatile. But by the same token, Compact System Cameras may be viewed as being awkwardly cramped and poorly suited to some kinds of photography…

Read full post

Zoom lenses and composition

Narrow-angle (top) and wide-angle (bottom) focal-lengths used to capture very similar compositions.

The arrival of zoom lenses changed the way photographers approached their subjects. In the days of primes you had to move to another spot to change the composition but zoom lenses removed the need for that… or did they?

Read full post

Macro lens choice

Macro comparison pictures showing the effect of focal length.

Macro lenses come in a variety of different focal lengths but how do you choose the best focal length for any given macro situation?

Read full post

Visual sharpness

Test image used for image sharpness comparison.

Numerical testing and visual sharpness are two very different things. Of the two, visual sharpness is probably more important but it is also harder to define.

Read full post


Jon Tarrant

Jon Tarrant

Former professional photographer and photography journalist, Jon has now put his physics degree to good use by becoming a physics teacher. He contributes technical features to WDC and is our primary lens tester, where his science background comes in very handy. He is the author of eight photography books on topics ranging from portraiture and lighting to Understanding Digital Cameras.