Bokeh doughnuts galore!
Using a 500mm mirror lens with a set aperture of f/8, any picture you take will have an extremely narrow depth of field (DOF) which usually means major issues when trying get a subject in sharp focus. Another problem is the dreaded ‘bokeh doughnut’ effect that mirror lenses tend to create, which can be seen above. This shot of dew-splattered grass highlights the thin DOF perfectly, with just a sliver of grass in focus and the water droplets on the grass either side of this sharp-spot have now been rendered as light rings.
For most photographers, this is a ruined shot and a failing of this type of lens. However, I consider a photo like this one as interesting as any other and believe it’s captured the surreal and wonderful effect of ‘bokeh doughnuts’ that no other lens can come close to replicating: for this reason alone, I think I will keep hold of my mirror lens for the foreseeable future…
Stretch the Horizon 