Newly arrived at the office. A new lens to play around with.

In the past few years I've read a bit about an elusive lens that Carl Zeiss made specifically for M mount cameras. It's the ZM 85mm, f4, Tele Tessar. It's a tiny short telephoto lens with a small maximum aperture but it makes up for its slow speed by being optically very, very good. Even when used wide open. I didn't actually buy this one. No cash traded hands. One of my friends bought the lens on a lark and was interested in trading me for a wider angle lens of which I had several copies. Always eager to play with new lenses so we quickly consummated the deal over coffee at our favorite downtown Whole Foods flagship store. 

Here's what Google's AI has to say about the lens: 

The 

Carl Zeiss Tele-Tessar T* 85mm f/4 ZM

 is a highly regarded, though niche, short telephoto lens for M-mount rangefinder cameras. It is often praised for its extreme sharpness and portability, making it a favorite for travel and landscape photography. 

Optical Performance

• Sharpness: It is considered one of the sharpest telephoto lenses for M-mount, delivering world-class results from f/5.6 onwards.
• Distortion: The lens exhibits virtually zero geometric distortion, making it excellent for architectural and landscape work.
• Micro-Contrast: Reviewers frequently highlight the "Zeiss look," characterized by high micro-contrast, vibrant colors, and 3D separation.
• Flare & CA: It features a T* anti-reflective coating that effectively resists flare and ghosting. Chromatic aberration is minimal and generally only visible in extreme high-contrast situations. 

Build and Handling

• Compact Design: Its modest f/4 aperture allows for a remarkably small and lightweight profile (approx. 310g), making it easy to carry.
• Mechanical Quality: The all-metal barrel and manual focus ring are noted for their smooth, precise, and durable feel.
• Focusing: It has a minimum focus distance of 0.9m (approx. 3 feet). 

Key Considerations

• Frameline Inaccuracy: Leica M rangefinders lack 85mm framelines; users must use the 90mm lines, which can lead to imprecise framing as the 85mm view is wider.
• Slow Aperture: The f/4 maximum aperture is "slow" for an 85mm lens, limiting its use in low light and reducing its ability to create heavily blurred backgrounds (bokeh) compared to f/1.4 or f/2 alternatives.
• Status: The lens is discontinued, meaning it is primarily available through the used market. 

Verdict

Pros	Cons
Exceptional sharpness and zero distortion	Modest f/4 maximum aperture
Extremely compact and travel-friendly	No dedicated 85mm framelines on Leica M
Robust all-metal build quality	Lens hood often sold separately or is bulky
Strong flare resistance and micro-contrast	Manual focus only (typical for rangefinders)

All the human reviews I have read, by people who actually possessed and used the lens, say pretty much the same things. I just got the lens this afternoon but I look forward to testing it throughout the week. 

It's unseasonably hot here and tomorrow is predicted to be even warmer. We're looking at an early January high temperature of about 85°. Definitely not weather in which to show off those new Christmas sweaters we all got. And it's sunny so the goulashes aren't getting a workout either....

I have high expectations for this lens. I've owned the 50mm, 35mm and 28mm ZM lenses and have found each of them to be sharp and very nicely contrasty. I'm expecting the same for this one!

Hope you are staying cool/or warm in this wild weather. A zany start to 2026 for us here in Texas.

Got the lens hood as part of the deal...