Holes of different shapes are also possible, to produce shaped bokeh.Īnother means to provide a smooth aperture and eliminate the diffraction pattern caused by aperture blades along with all lens artifacts is to eliminate both the lenses and the aperture by using a pinhole lens.Ī pinhole lens is no lens at all, it's simply a hole in front of the imager (film or sensor). Lenses that use a Waterhouse Aperture Plate such as the Petzval 58 Bokeh Control Art Lens from Lomography use interchangeable plates with various sized holes to control the aperture. The are also Smooth Trans Focus lenses that use an apodization filter to soften the edge of the bokeh.Īnother means to eliminate the spikes caused by aperture blades, essentially obtaining an infinite number of blades, is to use a bladeless design. If you could have an infinite number of blades you would have smooth and spike-free bokeh, but that is impractical to approach with most lenses having between 2 and 22 blades with 9 being enough for a modern lens design to produce (so-called) good bokeh. Note how a polygon aperture and a round aperture produce a different type of spike despite having the same number of blades. Depending upon the number of blades in your aperture you will get a different number of spikes.Īn even number of blades produces an equal number of spikes and an odd number of blades produces twice as many spikes as there are blades. Next up are spikes which are caused by diffraction from the aperture or leaf shutter blades. įlares and artifacts are caused by reflections within the lens body either from the lenses themselves or internal components and the lens body's wall - better lenses with better coatings and removal of screw-on Filters will reduce or eliminate these sources. Use of large square NDs that slide into a holder will allow for a maximum amount of fine adjustment. You usually get contrast reduction, flares, spikes, and artifacts when a bright source of light enters your lens directly.Ĭontrast reduction can be reduced or eliminated by using a graduated ND Filter, either circular or linear. Shooting directly into the Sun or a pinpoint light source results in a few effects (desirable or undesirable, depending upon your opinion) depending upon a number of factors, most of which can be controlled by a combination of techniques and circumstances. Intriguingly, one of the best names in the business, Zeiss, still uses their decades-old T* coating, which is often times inferior to Canon and Nikon multicoating, and vastly inferior to nanocoating. Some research might turn up other brands that offer it.
Currently, as far as I know, only Nikon and Canon offer lenses with quality nanocoats that really do the job well. So if you have the funds to invest in new, higher-quality lenses, I would say the best tool to combat flare these days is to get a lens with Nanocoating. Some light is still going to be reflected, however transmission improves considerably to 99.95%, and flare, ghosting, and contrast loss is minimized to the point where even if it does occur, it often doesn't matter. Unlike multicoating, which tries to utilize the nature of reflected light against itself, nanocoating attempts to guide as much light as possible into the lens and avoid reflection in the first place. Newer, more modern lens designs from the last five years use a new form of lens coating.called a nanocoating. However it does have its limitations, and flare still occurs, sometimes very badly, with intense light sources like the sun.
Its given us the ability to achieve nearly 99% transmission per lens element, etc. Multicoating has been used for decades, and is certainly an effective means of improving transmission and reducing undesirable artifacts like flare. One of the key tools we can use to mitigate flaring, ghosting, and contrast loss when photographing a scene with a bright light source (or just slightly off-axis light source in a corner) is to use miltocoated lenses.
I know this is an old question, however one particular answer was left out before.