CONTAX Planar G T* 35mm(Ms-optics)

Review

The Planar 35mm F2 is an autofocus lens released by Kyocera in 1996 along with the Contax G2. Here, we introduce a lens that has been modified by Ms-optics (Miyazaki Optical) to be Leica M mount (rangefinder camera rangefinder linked).

I also used this lens with the CONTAX G1 and CONTAX G2, but after selling them, I had MS-Optics (Miyazaki Optical) modify it to be Leica M mount rangefinder linked. The modified lens uses the MS-35 common helicoid for 35mm.

The main differences between the original lens and the Ms-optics modified lens are the following four points.

1. Fixing method for hood and filter frame
   • The front part of the lens barrel where the filter is attached moves in a straight line, so the filter does not rotate when focusing, making it easy to use PL filters
   • The lens barrel where the filter is attached rotates when focusing on the modified lens, making it difficult to use PL filters
2. Aperture click stop
   • The original lens has click stops for each aperture
   • The modified lens has a stepless aperture from F2.8 to F16
3. Rangefinder rangefinder linkage
   • The original lens is G mount, so it is autofocus (hereafter, AF)
   • The modified lens is linked to the rangefinder of the Leica M camera
4. Minimum shooting distance
   • Original lens is 0.5m
   • Modified lens is 0.7m

Because it is a planar format, the rear lens element and the mount surface are almost in the same position, so there are few problems when using it with various cameras. As shown in the example, the bokeh is beautiful, and it is an easy-to-use lens with few quirks. When using it with a mirrorless camera, it is easy to use the original lens via a mount adapter. Since lens prices have risen in the 2020s, it is difficult to decide whether to purchase this lens or the latest 35mm. In the 2010s, it was a lens with good cost performance, as it could be obtained for just under 30,000 yen, but now that it exceeds 50,000 yen, I feel that it is questionable whether it is worth investing that much in this old lens. Of course, if you like the design of the lens, there is no denying the purchase, as it will increase your desire to take photos.

There are several variations of the MS-35, which is part of the lens barrel of this modified lens. The MS-35 I own is an old model, and the angle of the lens base is shallow, making it difficult to grip the lens with my fingers. If you see one used, I recommend attaching it to your camera and checking that there are no problems with attaching and removing the lens.

When the MS-35 was first developed, it was designed for very small lenses on compact cameras such as the Kyocera T series used in C-TESS, and it does not seem to have been designed to be used with lenses with large lens barrels like this lens. The MS-45 used in the Planar 45mm F2, which I will introduce on another page, has a right-angled lens base and is quite wide, so it is not difficult to attach and remove the lens.

After that, I learned that the new helicoid MS-35 has an improved base, and I asked Ms-optics to change the helicoid part, but the owner, Mr. Miyazaki, told me that it is impossible to replace the helicoid of a modified lens due to the structure of the lens, so I gave up.

M-mount modifications to the Planar 35mm are also widely practiced overseas, and there are manufacturers that sell not only modified lenses but also helicoids so that users can modify them themselves (see the reference website for details).

As an aside, if you want to use the original Biogon 21mm F2.8 and Planar 35mm F2 with the CONTAX G1, you will need to update the camera.

There are used CONTAX G1 cameras for sale that have not been updated, and these two lenses cannot be used with these cameras.

To tell if your camera has been updated, if there is a green label on the film chamber, it has been updated. The CONTAX G2 is built to support all CONTAX G lenses, so there is no need to worry about this.

Specification

Name	HOLOGON	BIOGON	BIOGON	PLANAR	PLANAR	SONNAR	VARIO SONNAR
Focal length(mm)	16.5	21	28	35	45	90	35-70
Max aperture	8(fixed)	2.8	←	2	←	2.8	3.5-5.6
Min aperture	16(Attached filter)	22	←	16	←	22	←
Lens Construction	5elements in 3groups	9elements in 7groups	7elements in 5groups	←	6eleme0nts in 4group	5elements in 4groups	13elements in 8groups
Min distance(m)	0.3	0.5	0.5 0.8(*2)←	0.5	←	1.0	←
Lens length(mm)	11	35.5	30.5	31.5	38.5	63.0	54.0
Max diameter(mm)	57	59	56	56	56	56	60
Filter size(mm)	– Dedicated ND filters are available.	55	46	46	46	46	46
Weight(g)	120	200	150	160	190	240	290
Weight(g) M-mount	124	151	194 (222)*1	115	161	219 (259)*1	–
Release date	1994	1996	1994	1996	1994	1994	1999

Reference links

• Zeiss Photography Historical Products(There is a data sheet for the CONTAX G lens in the middle of the linked page.)
• FUNLEADER Web-site(Website of FUNLEADER, which sells modified lenses and helicoids for modification)
• Zeiss PLANAR description page by Wikipedia

Update history

• 2024.8.1
• 2024.02.16:Update article
• 2022.03.01:First draft

Affiliate links

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• Amazon Affiliate link for CONTAX lens
• Amazon Affiliate link for Ms-optics
• Amazon Affiliate link for CONTAX books