CONTAX G SONNAR T* 90mm(Ms-optics)

Review and Photo example the Kyocera CONTAX G mount 90mm.

Gallery

The sample photos were taken with the SONY α7Sii

The sample photos were taken with the HASSELBLAD X2D

Review

The Sonnar 90mm F2.8 is an autofocus lens released by Kyocera in 1994 along with the Contax G1. Here, we introduce a lens that has been modified by Ms-optics (Miyazaki Optical) to be Leica M mount (rangefinder camera rangefinder linked).

When I got my hands on a black Sonnar 90mm, I asked MS-Optics (Miyazaki Optical) to modify this lens to be Leica M mount rangefinder linked. It uses modified parts specifically for the Sonnar 90mm.

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

Focus movement points
- 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 including the aperture ring rotates
Aperture click stops
- The original lens has click stops for each aperture stop
- 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 referred to as 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, but when I got this Sonnar 90mm with a black barrel version, I requested a second modification, and just when the modified parts that adopted the new double helicoid were available, it was easier to use than the first modified lens, and Mr. Miyazaki, the representative of Ms-optics, said that he recommended the new parts.

Mr. Miyazaki also loves this lens, and when I requested the modification, he talked with amusement about how he often used this lens.

The lens’ depiction is no different from the original Sonnar, and the focal plane is depicted firmly from the widest aperture, and you can enjoy the melting depiction of the foreground and background bokeh. I also like the depiction where the highlights and shadows fall sharply when the exposure is underexposed. It seems that underexposed photography is compatible with the SONY α7Sii sensor, and it is quite dramatic to see the shadows being depicted in a variety of ways with crushed blacks, as in the example of a cat.

When using the original autofocus lens with the Contax G1 and G2, it was difficult to focus, so it was a lens that was used infrequently, but this modified M-mount lens has focusing accuracy that is satisfactory with the M-type Leica rangefinder. With a digital camera, you can further refine the focus using the EVF, so you can enjoy this lens at wide open aperture.

When used with a HASSELBLAD X2D, 11,045 pixels (about 98%) remained horizontally in a 3:2 crop. It seems usable in most areas.

In terms of lens construction, it is an advanced version of the last two 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 so strange that Zeiss called this lens a Sonnar.

Basically, most 90mm prime lenses rarely have a significant degradation in image quality, so in the past I have used the Apo Summicron M 90mm, Summicron M 90mm, Elmarit M 90mm, Macro Elmar M 90mm, and KM-HEXANON 90mm, but this lens is the only Leica M mount lens I have left. For the R mount, I still have the APO SUMMICRON R 90mm, which has a wonderful image quality that is different from that of this lens.

These are the only two 90mm focal lengths I have left, but I feel that these are enough.
I’m interested in the extremely expensive SUMMILUX 90mm F1.5 and the Chinese-made 90mm F1.25, which has been doing well recently.

Specification and Competitor

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