The full-frame Sony E-mount lens has the expected manual focus and aperture control rings, like other Voigtlander lenses. However, at the front end of the barrel, there is a third control ring — a silver one marked with “over” and “under” text and evenly arranged markings. This is the spherical aberration control ring. This allows photographers to under- or over-correct the lens’s spherical aberration, which changes the character of the out-of-focus elements in the frame.
When set to “under,” out-of-focus elements get much softer and rounder, and the overall image loses contrast and sharpness. On the other extreme end of the spectrum, when set to “over,” the lens is sharper and more contrasty. Turning the spherical aberration control ring has numerous other effects beyond changing the look of aberration. Adjusting this ring also shifts the focus position and changes the f-stop (within one-third of a stop, per Cosina). Further, turning the spherical aberration control ring to the “under” position will reduce peripheral light intensity, meaning photographers will contend with a vignette.
Speaking of default settings, in its “normal” setting, the Portrait Heliar 75mm f/1.8 behaves much like any other 75mm f/1.8 lens. Cosina says the lens promises high resolution and strong control over aberrations and other color shifts. The lens features just six elements arranged across three groups. It has a nine-bladed aperture diaphragm.
The Voigtlander Portrait Heliar 75mm f/1.8 delivers a maximum reproduction ratio of 1:7.4. It has a 62mm front filter thread, is 88 millimeters (3.5 inches) long, and weighs 560 grams (1.2 pounds).
