Design & Installation

What immediately stands out is how it mounts. The KEKS M Meter does not just slide into the hot shoe. It physically couples with the shutter speed dial, just like the original Leicameter MR4. Installation is deliberate and mechanical. Set the camera to Bulb, slide the meter in from the rear of the shoe, lift the large knob to clear the dial, then lower it to engage. Once seated, it feels locked in and purposeful, not like a meter that is merely perched on top of the camera.

I chose the black paint and brass version, which should surprise no one. I am notoriously obsessed with brass, and this one feels right at home sitting on my military tribute 1957 Leica M3 double stroke. The wear, the materials, and the weight all speak the same language.

In use, the experience is intuitive and fluid. You set your ISO, then turn the KEKS dial and the camera’s shutter dial together until the EV values align. The shutter priority meter gives you a clear EV reading, and from there you simply choose the aperture that matches your intended shutter speed. It becomes one continuous motion with no pause or second guessing, streamlining metering into a single seamless step.

The KEKS M is one of the few external meters designed specifically with Leica M shooters in mind. For those familiar with the old MR and MR4 Leicameters, this will feel like a modern continuation of that tradition. For those new to it, the KEKS M offers a purpose-built alternative to the generic hot shoe meters that just sit on top of the meter-less m cameras.

Metering Field

The KEKS M-Meter covers about the same field of view as a 50mm lens (roughly 30 degrees of average metering). That makes it a lot more practical than the MR4, which only reads a narrow 12-degree central spot, often compared to the 90mm framelines. With a 50mm lens, the KEKS M lines up almost perfectly. With a 35mm or wider, it still meters from the center, which remains quick and reliable in real-world use. I personally pre-ordered mine specifically for my 1957 Leica M3 Double Stroke, paired with the Leica 50mm f/1.4 Summilux (v3).

The upside of this 30-degree average metering is that it’s quick, forgiving, and matches nicely when you’re shooting 50mm, you point, it gives you a balanced reading, and you move on. But the trade-off is precision. In high-contrast scenes or when I’m using wider lenses, the meter is only sampling the center, so it can blend highlights and shadows into an exposure that doesn’t quite nail the subject.

On the street, where my style depends on catching fast, fleeting moments, that little lag in accuracy sometimes means I’m working off a reading that favors the average scene rather than the instant I’m chasing. Which is why, for occasions when I want to be more creative, drawing on my large format Zone System experience, I’d love to have at least the option of a default continuous mode, so I can sweep across tones and lock in exposure without that extra step slowing me down. If I can do this fast sweeping across, then I can easily pick a nice background, frame my shot, and just wait to trap my subject, giving me more room to be extra creative. And honestly, between the MR4’s narrow 90mm-like patch and the KEKS M’s 50mm view, I’m perfectly fine with the 50mm. Most of the time, it fits right in with how I shoot my Summilux 50 f/1.4.

Metering Modes

The KEKS M-Meter offers two metering modes, controlled by the back button:

1. Single Metering (Default): Press the back button once to take a single, momentary reading.
2. Continuous Metering: Double-click the back button to activate a mode that constantly updates the exposure reading. A small “C” appears on the display to confirm it’s enabled. To lock the reading or exit continuous mode, press the button again.

I mostly run the meter in continuous mode, but the double-click to activate slows me down. No big deal for slower shooting, but on the street that split second can cost the shot. With a UX/UI background, I get that KEKS had budgets and deadlines to hit. Still, a little beta testing could’ve smoothed this out. Small gripe though, the meter’s freed me from leaning so heavily on my M10 Monochrom or M6, and it’s made the M3 good enough that I’m happy setting the newer bodies aside. Feels good to fall for it again.

Where It Could Improve

Visible Shutter Speeds:

You can’t see what shutter speed you’re set to unless the meter is powered on and the OLED display is active. If the knob were slightly larger with engraved shutter speeds, you could glance down and know your setting instantly, even with the meter off.

Continuous Mode Default:

While the double-click activation works, it slows down fast-reacting shooting styles. Being able to set continuous metering as the default would better suit photographers chasing fleeting moments.

Features & Specs

Battery: 240mAh (about 10 hours runtime)

Charging: USB-C, full charge in 1 hour

Display: 1.3-inch OLED

Metering Field: about 50mm lens equivalent (30 degrees average)

Metering Modes: Single (default) / Continuous (toggle with double-click)

Exposure Mode: Shutter Priority

Exposure Compensation: -3 to +3 (1/3 stops)

Aperture Range: f/1.0 to f/128 (full, half, third stops) For Noctilux users, F/1 should be ok.

ISO Range: ISO 6–3200 (full, half, third stops)

EV Range: 1–20

Calibration: Fine-tunable for accuracy across bodies

Build & Finish

I ordered the Black Paint model in solid brass, which has a satisfying weight and presence. Over time, the paint will wear down to reveal brassing, a patina that feels right at home on my 1957 Leica M3 double stroke. I do plan on getting my M3 repainted black or olive green, and having a matching brass meter makes a lot of sense.

Of course, the M3 will live forever, but the KEKS M is still an electronic device, and like all electronics, it has a shelf life. The good news is that the rechargeable battery is easily replaceable if that day eventually comes, which gives it more longevity than most modern accessories. That reassurance makes the investment feel less like a disposable gadget and more like a real companion piece for the camera.

For those who prefer lighter finishes, the KEKS M is also available in Satin Chrome and Black Chrome, both made from aluminium with a smooth satin feel. In any finish, the meter complements Leica’s design language instead of clashing with it.

Falling Back in Love with 50mm

During the post-pandemic break, I found myself reaching for my M6 more often and naturally gravitating toward wider lenses, especially my street focal length favorite, the 28mm focal length. That shift shaped a lot of my style. But when I added the new KEKS M-meter to my Leica M3 double stroke and paired it with my 50mm f/1.4 Summilux V2, something clicked.

The Keks M-meter just feels like a perfect match for that setup, and in the process it’s made me fall back in love with the 50mm view. Where the M6 encouraged me to go wide, the M3 with the KEKS and the Summilux has reminded me how timeless and versatile a 50 can be when everything flows together.

Final Thoughts

The KEKS M isn’t just another hot shoe meter, it’s a Leicameter reimagined for modern use. It’s faster and more intuitive than the MR4, but still carries the same Leica-specific charm of being physically coupled to the camera’s shutter dial.

Yes, I’d love to see engraved shutter speeds and a continuous mode default option. But even with those small quirks, the KEKS M-meter has already earned a permanent spot on my M3. It looks the part, it feels right in use, and it’s even reignited my appreciation for the 50mm view.

What I find poetic is how it pairs with a camera like the M3. My 1957 double stroke will outlive me, no question; it’s all brass and gears, built for forever. The KEKS M, like any modern electronic device, won’t last that long. But the fact that its rechargeable battery is easily replaceable gives me some confidence that it won’t just become e-waste in a few years. In a way, it’s a reminder that while the M3 is timeless, the tools we add to it don’t have to be immortal, they just have to be good enough to keep us in love with shooting right now.

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Disclosure:

The views expressed in this article are solely my own. I received no payment, sponsorship, or incentive for this review. My work is motivated purely by my passion for photography.