M modified Sonnar T* 90mm
Review and Photo example the Kyocera CONTAX G mount 90mm.
Table of contents
Gallery
- 写真作例の撮影はSONY α7Sii、HASSELBLAD X2D
Review
1．Overview
The Sonnar 90mm F2.8 is an autofocus lens that Kyocera released together with the Contax G1 in 1994. Here we will introduce the lens that was modified to Leica M mount (rangefinder camera rangefinder linked) by Ms-optics (Miyazaki Optical).
When I got a black Sonnar 90mm lens, I asked MS-Optics (Miyazaki Optical) to modify the lens to Leica M mount rangefinder linked. Modification parts specifically for Sonnar 90mm were used.
The main differences between the original lens and the Ms-optics modified lens are the following three points.
- Focus movement area
- The outer lens barrel of the original lens is fixed, and the barrel housing the front element moves back and forth to focus; the front frame does not rotate when focusing.
- When the focus ring of the modified lens is turned, the front part of the lens rotates and moves as a whole, so the tip of the lens rotates, including the aperture ring.
- Aperture click stop
- The original lens has a click stop for each aperture.
- The modified lens has a stepless aperture from F2.8 to F22.
- Rangefinder rangefinder linkage
- The original lens is a G mount, so it is autofocus (hereafter, AF).
- The modified lens is linked to the rangefinder of a Leica M-type camera.
- The minimum shooting distance is 1m for both the original lens and the modified lens.
I had previously requested a modification of the titanium gold Sonnar 90mm, and when I got the black barrel version of the Sonnar 90mm and requested a second modification, it was just when the modified parts that adopted the new double helicoid were available.
This double helicoid version is easier to use than the first modified lens, and Mr. Miyazaki, the president of Ms-optics, said he would recommend this new part.
He looked like Amuro’s father in Gundam showing off his new parts. This lens is also one that Mr. Miyazaki loves dearly, and it was impressive to hear him talk with amusement about how he often used it on trips when I asked him to modify it.
2．Usability
The Sonnar 90mm F2.8 lens portrays the focal plane clearly even at full aperture, and you can enjoy the melting depiction of both the foreground and background bokeh. I also like the depiction where the highlights and shadows fall off sharply when the exposure is underexposed.
Shooting with a slightly underexposed image seems to be compatible with the SONY α7Sii sensor, and the depiction where the shadows are crushed into black is quite dramatic.
When the original lens was attached to the Contax G1 or G2 with autofocus, it was difficult to focus when shooting, so it was a lens that was used infrequently.
This M-mount modified lens has a focusing accuracy that is satisfactory with the M-type Leica’s double image overlapping viewfinder.
When used with a digital mirrorless camera, the focus can be further refined with the high-resolution EVF, and the depiction of this lens can be enjoyed from full aperture.
When used with a HASSELBLAD X2D, 11,045 pixels (about 98%) remained horizontally in a 3:2 crop. It seems usable for the most part.
3．Summary
In conclusion, to summarise the Sonnar 90mm F2.8, it is an orthodox medium telephoto lens that produces satisfying images even at full aperture.
Because the focal plane becomes thin at full aperture, it is safe to use a mirrorless camera to fine-tune the focus. When using a rangefinder camera, it is necessary to be aware of the subtle differences in focus position and deal with them when shooting.
Specification and Competitor
The lens construction is an advanced version of the two last elements of the Ernostar format glued together. The famous Sonnar-type 50mm F1.5 is also an advanced version of the Ernostar type, so it is not strange that Zeiss calls this lens a Sonnar.
Basically, most 90mm prime lenses rarely have a significant breakdown in image quality, so I have used the Apo Summicron M 90mm, Summicron M 90mm, Elmarit M 90mm, Macro Elmar M 90mm, and KM-HEXANON 90mm in the past, but this is the only Leica M-mount lens I have left.
The R-mount still has the APO SUMMICRON R 90mm, which has a different tendency to produce a wonderful image than the Sonnar 90mm.
These are the only two 90mm focal lengths I have left, but these are enough. The extremely expensive SUMMILUX 90mm F1.5 and the Chinese-made 90mm F1.25 which has been popular recently are both interesting models.
| Item | SONNAR | HEXANON |
| focal length(mm) | 90 | 90 |
| Maximum aperture | 2.8 | 2.8 |
| Minimum aperture | 22 | 22 |
| Leaf blade | 8 | 10 |
| Lens configuration | 5 elements in 4 groups | 5 elements in 4 groups |
| Minimum distance(m) | 1.0 | 1.0 |
| Lens length(mm) | 64.2 M-mount modified | 69 |
| Lens max diameter(mm) | 56 | 55 |
| Filter type | 46 | 46 |
| Weight(g) | 240 | 330 |
| Hood | GG-3 | Build in Hood |
| Lens mount | M-mount modified | LEICA M Compatible KM |
| Release date | 1994年 | 1999 |
| Price | ¥47,000 | ¥75,000 |
Reference links
- Wikipedia page describing the Zeiss Sonnar
- Zeiss Photography Historical Products(CONTAX G lens data sheet is available in the middle of the linked page)
- CONTAX G SONNAR 90mm Amazon sales site (affiliate link)
Update history
- 2025.5.13
- 2024.8.1
- 2024.02.16:Layout Modified
- 2024.01.14:Update
- 2023.03.27:initial draft
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