Mutar T* 1.4 for CONTAX645

1.4x teleconverter for telephoto lenses

A review and Photo example of the Mutar T* 1.4.

Gallery

Sample photo taken with the Leica S typ007.

Review

Usage
Lens overview
Comparison based on focal length

1．Usage

The Mutar x1.4 T* is a lens teleconverter (hereafter referred to as teleconverter) that multiplies the focal length of the Contax 645 lenses Sonnar 140mm, Sonnar 210mm, and Tele-Apotessar 350mm by 1.4.

When I checked the shooting results at 100% magnification on a monitor, the detailed depiction seemed to have good resolution without a teleconverter, but the difference was slight. There was almost no color bleeding caused by the teleconverter. Overall, I think it is an excellent teleconverter.

Due to the limitations of the lenses that can be used, the Mutar x1.4 seems to be in considerable stock on the used market as of 2024, and the cheapest ones can be found for around 10,000 yen. The median price is around 20,000 yen.

My impression after using it is that even if you attach a 1.4 teleconverter to a 140mm, the shooting range does not change dramatically, and I felt that cropping would be fine for a high-pixel camera.

2．Lens overview

The disadvantage of using this teleconverter is that the lens aperture F-number becomes darker by one step.

Only the three lenses mentioned above can be used, and the lens specifications of the Sonnar 140mm when the teleconverter is attached are focal length 140mm x 1.4 = 196mm, and the maximum aperture changes from 2.8 to 4, so the lens specifications are almost the same as those of the Sonnar 210mm. As of 2024, the Sonnar 210mm is an unpopular lens, and the price has plummeted to the point where you can find a good one for around 30,000 yen if you look for a used one, so there is almost no need to attach this Mutar x1.4 to the Sonnar 140mm.

Therefore, this teleconverter can essentially be said to be a teleconverter to be used with the Sonnar 210mm and the Tele Apotessar 350mm. Since I do not own the Tele Apotessar 350mm, it is exclusively for the Sonnar 210mm.

3．Comparison based on focal length

I wrote earlier that it has almost no practical use, but this time I checked the performance change when attached to a 140mm lens. I would have liked to take the 210mm lens with me and compare the three, but it would be too heavy to take them all out, so I decided not to. And before I could do that, I sold the 140mm because there were few uses for it.

140mm(x0.8)=112mm

Zoomup

140 x1.4(x0.8)=157mm

Zoomup

Specification

A converter that increases the focal length of the master lens by 1.4 times has the disadvantage that the F value becomes half a step darker.
Compatible lenses are Sonnar 140mm, Sonnar 210mm, and Tele ApoTessar 350mm.

Lens name	Mutar
Focal length(mm)	x1.4
Max aperture	It becomes half a step darker than the attached lens.
Min aperture	It becomes half a step darker than the attached lens.
Lens Construction	7 elements in 5 groups
Min distance(m)	Same as attached lens
Lens length(mm)	41
Max diameter(mm)	82
Filter Size(mm)	–
Weight(g)	510
Release date	1999

The performance changes when a teleconverter is installed are as follows.

master lens Focal length	master lens F value	Focal length after installing teleconverter	F value after installing teleconverter
140mm	2.8	196	4
210mm	4	294	5.6
350mm	4	490	5.6

Reference links

Update history

2023.07.16:Update article
2024.03.04:Update article
2023.06.25:First draft

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