Sun Optical 60-135mm f/3.5 Multi-Zoom MC (Sigma YS Mount)

SUN-ZOOM 60-135mm f/3.5 MC
by Sun Optical (Sigma YS Mount)

2017.09.22 - Published

2021.08.24 - Re-written, re-edit video

SUN OPTICAL

MULTI-ZOOM
60-135mm f/3.5

Multi-Coated

Maker - Sun Optical

Year - Mid to late 1970s

Mount - Sigma YS (Auto Diaphragm)

Focusing - Manual, non-AF

Zoom Type - Two ring, parfocal
Minimum Focusing - 2 meters
Focus Throw -3/4 circle (270 degrees)

Filter Thread Ø - 58mm

Aperture - f/3.5 - f/22

Maximum 60mm - f/3.5

Maximum 135mm - f/3.5

Iris Blades - 5

Optical - ? elements/groups
Multicoated elements

Built-in retractable hood
Made in Japan

Photo Album

https://photos.app.goo.gl/WBMEZjNNy9EYu5ET8

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Impressions

Here is a very rare SUN MULTI ZOOM 60-135mm f/3.5 MC made by Sun Optical around the late 1970s. It is a zoom lens with constant maximum aperture of f/3.5 throughout its whole range of 60mm up to 135mm, which makes it a nice portrait lens. There's only a rare handful of them around.

This small lens has a very stylish design, made of all-metal materials but surprisingly relatively lightweight. It comes with a very useful retractable lens hood, and also its original Sun Lens screw-on front cap. This lens uses the Sigma YS (Yamaki System) mount, which is basically a Tamron T-mount screw thread with the addition of support for auto diaphragm. Do not mistake T-mount for the Praktica M42 thread mount (often wrongfully called Pentax M42 thread mount, since Praktica is the one who invented it).

It is clearly labeled as multi-coated elements, although it appears that different individual elements have sheen of amber, blue and purple color. It is likely an early-type multicoating. The purpose of coating is to reduce reflections, which should improve flare control, contrast and colors.

This is a 2x optical zoom. Less zoom range means sharper output. Due to limited technology at the time, developers could only produce zooms with a small zoom range. The Sun 60-135mm f/3.5 is consistently sharp wide at f/3.5 from 60mm to 135mm. This is a great feat considering zooms were thought of as inferior in its day.

I'd like to think of this as a 100mm f/3.5 prime lens that can zoom wider at 60mm or longer to 135mm. This lens always produced clear pictures as if shot with a prime lens, no matter what focal length. It is not a macro-lens type of sharpness, but one that is sharp enough but still renders skin beautifully. Which makes it an awesome portrait lens.

It has a minimum focusing distance of 2 meters, which is the typical distance that one shoots portraits with. Because of this distance, the lens may find limited uses such as for portraiture, landscape, street photography, candid, wildlife, or events. You could still shoot plentiful with it with so much joy. There is a later version with MACRO features that allows you to focus much closer; perhaps you want to look for that one.

This is what you can get with 2 meters...
60mm - half body

90mm - head and shoulder

135mm - head

Aside from the minimum focusing distance of 2 meters, the lens can only be shot handheld (it does not have tripod collar) because it could be front-heavy even on a digital SLR when the camera body is mounted on a tripod. Other than those two things, they won't ever detract from how awesome this lens really is. It is one of those lenses I want to have again.

Another feature which you won't find very often with zooms, is that it is PARFOCAL. It means that your focus remains constant when you zoom (the opposite of 'varifocal', which most zooms are). This is why it's also very lovely to shoot videos with. That, and the constant maximum of f/3.5 from 60mm to 135mm. It really feels like I'm shooting with 3 prime lenses in one zoom. This lens is ultra-rare and hard to find. Sometimes I wish to not have sold it years ago, it was an awesome lens!

Sun Optical was one of the first third-party companies to offer lenses for SLR cameras. Its history begins as 'Kajiro Kogaku', a company founded by Kajiro Hitoshi in 1939; they sold lenses under the name 'K.O.L.' (Kajiro Optical Laboratory). It was renamed 'Gojo Koki Seisakusho' in 1941, but then ceased operation in 1945. The company was revived as 'Sun Koki' and then began using the name 'Sun Optical Co., Ltd.' from the 1950s. Again, they changed name to 'Goto Sun' around 1981. They were last known to exist in 1983 and disappeared shortly (the introduction of AF lenses to the market killed many companies). Goyo Optical absorbed them in the late 1980s; the same company that sold the Noktor 50mm f/0.95 in Micro Four Thirds mount from March 2010.