Keks KM02 OLED Light Meter Review

Keks KM02 OLED Light Meter Review

2000 1125 James Tocchio

Back in 2020, Keks released a beautiful and effective OLED light meter called the EM01. The meter worked great and I found that it brought new life to my Nikon SP, a meter-less film camera. I loved the EM01 so much that I stocked them in my shop. Now, Keks has updated their light meter and released a new model, the Keks KM02. Much to my surprise, the new meter is quite an upgrade. It retains everything good about the original meter and improves on almost everything that I’d originally nitpicked in the earlier model.

The KM02 is smaller and lighter than the previous model and it has a (slightly) longer battery life. The buttons click nicer than those of its predecessor, and tiny improvements in the user interface complement the device. While all of this combines to smooth away the figurative rough edges of the earlier model, the biggest improvement comes in the new meters’ customization options and the finer points of its functionality.

Specifically interesting is that this new meter is compatible with lower ISO films than the previous version (the KM02 dips down to ISO 6 where the previous model bottomed out at ISO 50). It also meters smaller apertures than the previous model, allows for exposure compensation and for selecting a desired user bias for over- or under-exposure, and offers both single and continuous metering modes. That’s a lot of good stuff!

I do have a couple of complaints. But we’ll save those for the end.

Specs of the Keks KM02

  • Material: Aluminum (black or chrome colors)
  • Dimensions: 42 x 27 x 15.5mm
  • Weight: 29 grams
  • Battery: 220mAh Lithium Ion (2.5 hours to fully charge)
  • Battery Life: 21 hours (always on)
  • Charging Port: USB Type C
  • Monitor: 0.91″ OLED screen
  • Display Modes: Detailed and Standard
  • Shoe Mounts: Three removable aluminum shoe mount sizes provided, can be attached in one of five positions
  • Metering: 30 degree average metering (approximately 50mm lens viewing angle)
  • Metering Mode: Single metering or Continuous metering
  • Exposure Modes: Aperture Priority or Shutter Priority
  • Exposure Compensation Reading: -3 to +3 in 1/3 stop increments
  • Aperture Stops: Full, half, or third
  • Aperture Values: f/1.0 to f/128
  • Shutter Stops: Full, half, or third
  • Shutter Speeds: 30 seconds to 1/8000th of a second
  • ISO Stops: Full, half, or third
  • ISO Values: ISO 6 to ISO 102,4000
  • EV Range: 1-2015.5mm

Keks KM02 in Use

I spent three months using the Keks KM02 before writing this review, and its operation is (mostly) simple.

The meter mounts to any camera with a hot or cold shoe, and its mounting point is adjustable. By unscrewing the mount we’re able to attach larger or smaller mounts, as well as position the mount in the center or to the side of the bottom of the meter. There are a total of five different mounting positions (two more than the first model), which makes the meter suited to nearly any camera. Keks even offers a stick-on accessory shoe (sold separately), which allows the Keks meter to be mounted to cameras that lack shoes (such as the incredible Olympus Pen F).

Once the meter is mounted to the camera, its operation is simple. To set the ISO to whatever film we have loaded in the camera, we must only hold the metering button (the circular one on the back of the unit next to the screen) and then press either up or down on the +/- adjustment buttons (the two on the top, to the right). Once we’ve selected the correct ISO we’re ready to meter.

The unit works in a way that’s similar to a camera’s aperture-priority or shutter-priority mode. After setting the ISO we then select either the desired aperture or shutter speed, after which, pressing the metering button on the back will result in an instant calculation and display of the final variable which will result in a correct exposure. We can also set the meter to continually meter, in which case the reading will refresh every 0.6 seconds with a new, accurate reading.

To give an example, say we’re shooting 400 ISO film and we want to shoot a shot with the lens aperture set to f/8. We set our ISO to 400, and then simply press the plus or minus button until the meter is set to f/8. After that, pressing the metering button on the back will tell us which shutter speed we should choose. The ISO, aperture, and shutter speed values are all adjustable and displayed in increments which are determined by the user (full stops, half stops, or third stops).

The meter’s 30º metering angle of view strikes a good balance between average and selective metering. It corresponds well with the readings I’m getting from my Leica R5 in side-by-side comparison when the R5 is set to selective metering mode.

The OLED display on the back of the meter is bright and vibrant and I’ve not encountered any issues shooting in daylight. We can manually adjust the screen’s brightness if need be, or set it to auto-brightness, which is nice.

It has two different display modes this time around. The Detailed Display Mode shows a comprehensive readout which displays the selected ISO, the selected shutter speed or aperture (depending which mode we’re in) and the reciprocal parameter which will result in a proper exposure, as well as the Exposure Value and Lux Value, a battery life display, and an indicator for when exposure compensation mode is active. The Standard Display Mode shows less information; the selected ISO, the selected shutter speed or aperture (depending which mode we’re in) and the reciprocal parameter which will result in a proper exposure, battery indicator, and exposure compensation status. There’s also an Inverted Display Mode, for cameras which have their hot or cold shoes on the bottom (such as the Rollei 35 cameras).

An interesting addition above the original light meter is the ability of the new meter to store custom data. The user is able to create parameters for three lenses and three cameras. This is useful in situations where, for example, a camera only offers single stop increments for its shutter speeds or a lens stops down in half or single stop increments, rather than the more typical third stop increments. By setting these custom load-outs (to borrow a military term) the meter works more conveniently for any given photographer and their individual gear.

Additionally the Keks KM02 adds the ability to adjust exposure compensation. This will be huge for those who like to push- or pull-process their film. We can easily use the exposure comp to achieve readings plus or minus up to three stops.

And finally another smart inclusion is a mode called Metering Results, which is a sort of user-selectable metering bias where the user can tell the meter to facor under-exposure, over-exposure, or to meter normally. I see this being a massive benefit, since I typically over-expose every color negative I shoot by a half stop or full stop. This has been why I typically use aperture priority cameras with exposure compensation built in, after all. They make it so easy.

When the battery runs down we plug it into a USB type C connector and it charges up again pretty quickly. It uses a Lithium Ion battery, which some people dislike. I can understand why. Other meters, like the Voigtlander VC Meter, ever popular, uses standard replaceable batteries. That’s nice, in that it will likely be usable for as long as batteries are being made. A built-in Lithium Ion battery is much harder to replace. It can be done (I’ve removed the plate on the KM02 and I can see that a new battery would simply need to be soldered in – not a terrible job), but it’s not as easy as popping a couple of LR44’s into a slot.

Still, I don’t mind a rechargeable Lithium Ion battery. Nothing is permanent. Nothing is perfect. But this is convenient.


While the Keks KM02 is an upgrade over the original, for sure, it’s still not as comprehensive a meter as others on the market. Meters made by Sekonic, Gossen, and others will do more than the Keks KM02 – things like flash calculation and spot metering, as well as average metering. But as expected, meters with this expanded functionality are bigger, heavier, and more expensive than the Keks (which still only costs approximately $110).

When the original Keks EM01 released it was the best little meter available for around $100. Since then, a number of similarly compact and similarly-priced meters have joined the fight. The Reveni Labs light meter is well-regarded. I’ve not used one myself. There’s the Doomo S, which is probably a better choice if you’re someone who wants their shoe-mount light meter to have a screen on top rather than on the back. The Hedeco light meter offers wider aperture setting (f/0.7 compared the the Keks’ f/1.0), so if you’re using the new Nikon Z mount Noct Nikkor (although how you’d be using that without a meter, I don’t know) or a Noctilux, maybe buy that one.

Actually, let me stop there. I won’t list all of the competitors because I’ve not used them. I’ve only read their spec sheets and then decided I didn’t need to bother. And the reason I didn’t need to bother is because the Keks did everything I needed, inexpensively, and elegantly. It was the best looking meter on the market, it was priced right, and it worked perfectly. Nothing about that calculus has changed in the last two years. The newer Keks is a better Keks, and it’s still the best $100 shoe-mount light meter on the market. That’s not to say that the others aren’t good meters. I just don’t see any one of them being notably better than the Keks.

Final Thoughts

Is the Keks KM02 a perfect product? Of course it isn’t. I’ve been reviewing camera gear every day for almost a decade now and I’ve never found a perfect product. They just don’t exist. So, where could the Keks improve?

Well, one look at the user manual should give some clue. This is a complicated little device. The four buttons on top are unlabeled, so finding my way through the menus has been an annoyance. It took me reading the manual to remember how to adjust the set ISO. That shouldn’t happen. I think that simply engraving some user interface images onto the buttons or the area surrounding the buttons would help sort this.

I also mentioned in my review of the Keks EM01 that I disliked that the mount was made out of plastic. In that review I specifically demanded that the mount be made of aluminum, as is the body of the meter. Well, they made the new model’s mounts out of aluminum. Wish granted, I guess. And while I personally love it, I was reminded by a reader that plastic might be better.

The theory presented was that, in the event of an accident, the plastic mount of the meter would break where a metal mount would possibly break or bend the accessory shoe of the camera. A fair point, and now I’m not sure which I prefer. I suppose I’ll just never drop my camera and enjoy the metallic mount.

Those qualms noted, I do think the Keks KM02 is the right meter for the job. It does everything I need it to do, and in fact it does more than I really want. I won’t actually use some of its features (such as the custom camera or lens settings), but it’s nice that they’re included for those who will. For everyday shooting with a meter-less camera, it works beautifully, looks great, and meters well. That’s just about all I need to actually use my meter-less Nikon.

Get your Keks KM02 from their website here

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James Tocchio

James Tocchio is a writer and photographer, and the founder of Casual Photophile. He’s spent years researching, collecting, and shooting classic and collectible cameras. In addition to his work here, he’s also the founder of the online camera shop

All stories by:James Tocchio
  • Great Meter from North America 😉
    Does a great job for a right price.
    I wanted a meter for long time. Finally this one could be the one.
    Thank you so much.
    And a new review 😉 thank you

  • Hi James,

    Great review, thank you.

    Can you compose then meter while looking through the viewfinder, or do you need to take the camera away from your eye to meter? (Obviously you need to take the camera away from your eye too read the meter).

    And how well do you think it would work (the use, not the quality of the metering) on a tlr with a vertical cold shoe?

    • It’s a little tight to put your thumb up and press the meter button with the camera pressed against your eye, but it’s possible. I find I simply raise the camera up and take a reading, set my settings, then compose and shoot. It’s obviously not as nice as having a camera with a meter in the viewfinder, but that’s why we’re using an external meter, so no getting around it.

      As for the TLR, it works great. No issues whatever. Hope this helps.

  • I’m guessing that the dots on the right of the screen show battery strength. I have the 01, which lacks that, but otherwise works fine. Don’t think I will be upgrading. Thanks for the review.

  • Thanks for the review James, I have just ordered one.

  • Hi James,

    Thanks for the review. Partly because I’m in the EU, partly because the specs and range just make more sense, I’m getting a Lime 2 from Hedeco for my birthday. Granted, with most films and within most scenarios, this can do what the Lime 2 does. Still, made in Germany, and with a heavily upgraded build quality, I’m looking forward to seeing the L2 on my Bronica.

  • I’d order one in a heartbeat, but it’s for an Exakta VX and I’m not sure it won’t cover something important… The Raveni is tiny, so fewer worries.

  • I bought one based on this review, very good! I picked up the basics for use quickly, however I haven’t worked out how you let it know which lens settings you are using from the 3 you can save. Any advice? I use an SP, great camera and very cool design : )

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James Tocchio

James Tocchio is a writer and photographer, and the founder of Casual Photophile. He’s spent years researching, collecting, and shooting classic and collectible cameras. In addition to his work here, he’s also the founder of the online camera shop

All stories by:James Tocchio