Mod Planar T* 45
Review of using a Kyocera CONTAX G-mount 45mm F2 lens modified by MS-Optics (Miyazaki Kogaku) to Leica M mount with Leica M digital camera.
Table of contents
Gallery
- The photo examples were taken with the HASELBLAD X2D.
- The photo examples were taken with the Leica M-P typ240
Review
1．Overview
The modified M-mount Planar 45mm is an autofocus lens released by Kyocera in 1994 along with the Contax G1. Here, we introduce a lens modified to Leica M mount (rangefinder camera rangefinder linked) by Ms-optics (Miyazaki Optical).
I also used this lens with the CONTAX G1 and CONTAX G2, but after selling them, I purchased a lens modified to Leica M mount rangefinder linked by MS-Optics (Miyazaki Optical). I wrote about how I purchased the lens in an aside. The modified lens uses the MS-50, a common helicoid for 50mm.
The main differences between the original lens and the Ms-optics modified lens are the following four points.
- 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
- Aperture click stops
- The original lens has click stops for each aperture
- The modified lens has a stepless aperture from F2.8 to F16
- M-type Leica rangefinder link
- The original lens is a G mount, so it does not link
- The modified lens links to the rangefinder of the Leica M-type camera
- Minimum shooting distance
- Original lens is 0.5m
- Modified lens is 0.7m
2．Usability
The lens has a classic planar structure, and the coating is old, so purple fringes may appear around the subject depending on the lighting conditions, such as in backlight. The overall depiction has the feel of an old lens.
In modified lenses, the aperture ring is located at the front of the lens, at the thickest part of the lens barrel, and it is often in a different position when removed from the camera bag. For this reason, it would be easier to use if the aperture ring was a little stiffer.
There is no problem with rangefinder linkage with M-type Leicas, and the correct focus position can be obtained by matching the double image. If the focus position is out of sync, it is probably possible to adjust it with Ms-Optics, so it is best to contact Ms-Optics and check.
There is no viewfinder frame for M-type Leicas with a focal length of 45mm. There are no external viewfinders with 45mm either.
When using with a Leica M viewfinder, if you shoot with the image of shooting a little larger while looking at the 50mm frame, you can generally take the picture as you imagined.
When using the electronic viewfinder on a mirrorless camera, the image through the lens is depicted directly, so there are no issues with the viewfinder frame.
3．Summary
In conclusion, to sum up the modified M-mount Planar 45mm, the image quality is the same as the original Planar 45mm.
The only change to the lens is that it is compatible with the rangefinder of an M-type Leica camera, so if you want to use the G-mount Planar 45mm with a Leica M-type rangefinder, you will need to use a modified lens from Ms-Optics or another company.
If you are using it with a mirrorless camera, you do not need to prepare a modified lens, just check whether a mount adapter is available for the camera you want to use the original G mount with.
Adapters are available for most mirrorless cameras, including Sony E, Micro Four Thirds, Fujifilm X, Canon RF, Nikon Z, and L-mount, and it all depends on the availability of adapters on the market.
・Digression side note
The details of how I got this lens are as follows: I saw it at a used camera shop in Shinbashi that no longer exists around 2007. I had already used it with the film cameras CONTAX G1 and G2, and I knew that I was satisfied with the image quality of the G-mount version, so I was tempted by the appeal of being able to use the Planar 45mm with an M-mount rangefinder camera in conjunction with the rangefinder, and purchased this M-mount lens.
When I attached the lens to my camera at home and adjusted the focus, I found that the lens barrel and helicoid were not firmly fixed, and the lens barrel fell off the helicoid, so it was a defective product.
The modified lens diagnosis certificate included with the purchased lens had the contact information of the modifier written on it, so I contacted Mr. Sadayasu Miyazaki, the founder of Ms-Optics, and he repaired the lens free of charge.
This was the beginning of my relationship with Mr. Miyazaki, who was an individual lens builder at the time. This is a lens that holds many memories for me.
Starting with the acquisition of this lens, I went on to convert other G-mount lenses to M-mount: Planar 35mm, Biogon 21mm, Hologon 16mm, and Sonnar 90mm.
After that, when I acquired a digital Leica M camera, these converted M-mount lenses became easier to use, and although I have bought and sold M-mount lenses from other brands, I have continued to keep and use the converted G-mount lenses.
List of modified G mount to M mount lenses
There are companies overseas that modify CONTAX G lenses to the M mount, and some of them sell not only modified lenses but also just helicoids. For details, please refer to the website in the reference link.
| 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. Changes to f/8 > 16 to alleviate peripheral light attenuation. | 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 |
*2: Minimum focus distance of AVENON modified lens
Reference links
- Zeiss Photography Historical Products (There is a data sheet for the CONTAX G lenses in the middle of the linked page.)
- Website of FUNLEADER (Website of FUNLEADER, which sells modified lenses and helicoids for modification)
- Zeiss PLANAR description page by Wikipedia
Update history
- 2025.4.13
- 2024.8.1
- 2024.02.16:Update article
- 2022.03.03:First draft
Affiliate links
- CONTAX lens・Ads by Amazon
- Ms-optics・Ads by Amazon
- CONTAX books・Ads by Amazon
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