Another SONY α System: Utilize Mount Adapter(5)

By Junichi Date / CAPA asia

Bringing out the attractive optical performance of old lenses with unique character: Kiyohara Soft VK70R lens

Thus one begins to take notice of lenses from the film era. These include more than just classic lenses (so-called “old lenses”). There are many lenses from the heyday of film, sold in the 1980s and 1990s, which have unique optical characteristics. These lenses (called kusedama or meidama in Japanese) have attractions not found in the latest lenses. Among these lenses from the film era, there are some whose optical characteristics change completely between fully opened and stopped-down aperture. There are others which exhibit flare even when shooting at aperture. But provide excellent resolution, and are acceptable even today when checked at actual pixel size. Aspherical lenses and similar types do not use special glass materials, and thus are unique in that many have a straightforward blurry character.

The unique advantage of the SONY α7RII is that it can optimize the optical performance of these earlier replacement lenses for SLR cameras with a full-frame angle of view. Also, if the focal length is manually input, hand shaking can be suppressed using 5-axis in-body image stabilization. This is an irresistible camera for the lens connoisseur.

■ Kiyohara Soft lens
Soft focus became popular in the 1980s, and soft focus lens were marketed by various manufacturers (If you would like to know more about the history, search the Internet for: Vest Pocket Kodak lens* without hood). The Kiyohara Soft VK70R and VK50R lenses from Kiyohara Optics were designed to reproduce the optical performance of this Vest Pocket Kodak lens (see the main text below). Today, soft focus effects can be achieved easily through image processing, but with optical soft focus the blurring of light is different. Also, with a soft focus lens, there is a difference between the resolution peak and contrast peak, and if the optical viewfinder of a single-lens reflex (SLR) camera is used, focusing will be done at the contrast peak, so there are often failures where focus fallson the background. If you use the Focus Magnifier function of the α7RII you can clearly distinguish the resolution peak, and fully bring out the original resolution and the softness of a soft focus lens.
* This lens was one of the Vest Pocket camera lenses sold by the Eastman Kodak Company from 1912 to 1926, and it provides a beautiful soft focus effect obtained from its spherical aberration.

Kiyohara Kogaku VK70R 70 mm f/5 lens
Format: 35mm SLR
Focal length: 70mm
Focusing: Manual Focus (MF)
Lens mounts: T2 mount
Optical design: 2 elements in 1 group
Max. aperture: f5
Min. aperture: f11
Features: Soft lens
Filter Ø : 49mm
Weight : 136g /4,8oz
Length : 49mm /1,9in

SONY α7RII: 5-axis image stabilization in full-frame glory

Page Top