![]() It doesn\’t take an experienced eye to see how f/5.6 has a small but visibleĮdge. That the only effect being seen is diffraction. Was no wind, cable release (of course) and every other measure possible to ensure These were taken with a Phase One P45 39 Megapixel back onĪ Linhof 679cs camera. Utility in Capture One raw conversion software. These are screen grabs are from the Focus These 100% crops of the full frame have not been processed in any way, with Stop at a time, and the shutter speed opened up accordingly to maintain exposure. The frames below were taken at every available aperture with a 180mmį/5.6 Rodenstock APO Sironar HR lens. A lens such as this is said to be “diffraction limited”.Īnd with a diffraction limited lens, wide apertures demand higher resolution The finest lens is one that produces an image whose quality is limited onlyīy diffraction. Since diffraction cannot be completely eliminated, Lenses for use with a 39 Megapixel Phase One P45 back, I wasĬurious to see whether Rodenstock’s claim that these lenses were diffraction This is why it’s important to test each lens in your arsenal for the pointĪt which they are visibly affected by diffraction.Īfter recently purchasing four ultra-high performance Rodenstock medium format Of light hitting the sensor or film, but as the aperture is stopped down theĪmount of diffracted light becomes a larger percentage of the total amount of At largerĪpertures this diffracted light is only a small percentage of the total amount The reason for this is that theĮdges of the diaphragm blades in the lens tend to disperse the light. Reducing sharpness, though DOF is increased. You stop down the aperture on a lens the light passing through tends to diffract, But unfortunately these two demands can be mutually exclusive. Rather, it’s purpose is to bring to the attention of photographers who may not be aware of the issue that there is no free lunch when it comes to achieving greater depth of field though stopping down.Įvery photographer wants both maximum resolution and maximum depth This is not a comprehensive treatise on the subject of lens diffraction effects. This article was written by Michael Reichmann and originally published Jan 13 2009 ![]()
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