Hedeco Lime One Compact Light Meter Review and Launch on Kickstarter

The Hedeco Lime One compact shoe mount light meter has just launched on Kickstarter – I have been playing with a beta version for the last week, so thought I would share my a little review alongside the news of its launch.

A few weeks ago I was contacted by Johannes Heberlein, the man behind the Hedeco Lime One compact light meter. There has been a little bit of a flurry of compact light meters appearing on the market recently, not least the Reveni that I reviewed just a few weeks ago. As such, I must admit, I was a little sceptical about the need for another new one. But, after a little bit of an email chat about his design, my scepticism turned into me being quite keen to have a play.

Size and design

The Reveni I reviewed the other week was designed to be so small it would take up little more space on any camera that the hot/cold shoe it’s mounted to. To achieve this, it is effectively a cube shape with a screen on the back and buttons on the top. As I talk about in the review, the advantage of this is that it can fit on any camera I can think of. With that size has come some sacrifice though – the button operation make it slightly slow to use.

Johannes has chosen a different approach for the Hedeco Lime One light meter. Where the Revini is a cube, the Hedeco is a much more low profile design that’s around twice the width of the shoe it mounts to and deeper too. This isn’t to say it’s big – it is still smaller than the Voigtlander VCii meter that it is a similar shape too. But, like the Voigtlander, without the additional 3D printed accessories it comes with, this will mean that the Hedeco Lime One won’t mount to as many cameras as easily as the Reveni will.

Hedeco size comparison
Reveni, Hedeco, Voigtlander

The chosen materials are different too – or at least some of them are. Unlike the Reveni which is entirely made of 3D printed nylon, the outer shell of the Hedeco is made of aluminium. Johannes did point out that I should ignore the hand-countersunk screw holes which are a little uneven on the beta one I have here.

In terms of the feel of it in the hand – it’s pretty nice. Despite the metal shell, it weighs so little you’d never notice it on the camera. This is nice in some ways, but for something that looks metallic I was somehow left wanting more of a solid feel to it. The button has a nice click, and – as will come to in a mo – the metal jog dial feels nice to use too, so all is far from lost.

Hedeco button
Hedeco Lime One button
Hedeco jog dial
Hedeco Lime One jog dial


The Hedeco Lime One has 4 modes of operation: Aperture priority, shutter priority, manual and EV mode. Aperture priority allows you to cycle through apertures giving you a shutter speed. Shutter priority allows you to cycle through shutter speeds giving you an aperture. Manual mode allows you to cycle through both and displays and under/overexposure readout alongside a scale which reads up to -/+ 3ev. EV mode displays an EV readout based on the selected ISO.

In the aperture priority, shutter priority and EV modes modes it is possible to compensate the exposure too, again up to -/+3ev.

Beyond these modes the ISO can be set as well as there being an option to calibrate the meter – though no calibration was required, it reads the same as my Voigtlander meter out of he box.


The Hedeco Lime One meter reading is displayed on the top of the meter via a small but milti-lined OLED screen. I have had no issue at all reading the screen myself, but if you have issues with your eyesight, you might need your reading glasses as the numbers and letters are quite small. That said, the screen is bright, and seems to dim slightly in lower light which I thought was a nice touch.

Hedeco Lime One top


One thing I really liked about the Reveni meter was the extreme range of settings. The range on the Hedeco Lime One isn’t quite as extreme. The shutter speeds range from 24 minutes to 1/8000, the apertures from f/0.7 to f/128 and the ISOs from 3 to 12800. It does all of these in 3rd stops across the whole range which gives more options than the Reveni. Though I struggle to imaging many people will make use of most of the selectable setting, I suppose they are nice to have.

Speed & Controls

Because the Hedeco Lime One only has a single button and jog wheel, I initially imagined that it would be slow or fiddly to use. In fact, my first experience only backed up that concern. Fortunately, my initial experience was almost entirely down to the fact that I hadn’t taken a moment to read the manual. It did take a few minutes to work out exactly what was going on, but once I got used to it, I found it really quite quick to use.

To activate the meter, you just press the button – once pressed, the meter gives a live reading, this is unlike the Reveni which locks the reading each time you click the read button. Which of these works better will come down to the individual – I am happy with each way of working. To change settings, you spin the jog dial. The dial is clicked which gives a nice haptic sensation of clicking through the settings. It also feels very responsive and jogs through the settings as quick as you can turn the dial. This does indeed make it feel much quicker to use than the Reveni.

When in aperture or shutter priority, pressing and holding the the button allows you to jog through the exposure compensation, and when in manual mode the dial changes the shutter speed by itself and the aperture when the button is held.

To get into or out of the menu, you double click the button. This works ok, but no matter how much I use it, I still find it a little clunky feeling. Would a second button to access the menu make it feel less clunky? I’m not sure to be honest. There is something in the elegance of all the function being driven by a single button and dial. It’s also the case that once your out and about shooting, you shouldn’t need to go into the menu at all… there’s just something a little awkward about it. Though in fairness, as with the Reveni, this is the price you have to pay for a light meter to be so small.

Another size comparison – Hedeco, Voigtlander, Reveni


The Hedeco Lime One is powered by a CR2032 battery – these are less commonly found than the LR44 that the Reveni uses, but are nonetheless readily available watch batteries. I haven’t had the meter long enough to comment on how long the battery lasts.

Meter Accuracy

As already mentioned, the Hedeco Lime One seems to match my Voigtlander meter perfectly. It’s also accurate to my phone and when pointed at solid colour objects is matches my M10 too. I haven’t had a chance to talk to Johannes in the same detail as I spoke to Matt about the metering field of view or pattern, nor have I had much of a chance to experiment, but it seems to respond similarly to both the Reveni and Voigtlander which have 45 degree readings to roughly match a normal lens.

Hedeco Lime One Battery compartment
Here you can see the Hedeco Lime One Battery compartment next to the hole for the light receptor

Final Thoughts

The Hedeco Lime One is yet another shoe mount light meter to hit the market in recent times. In fact, where we had very few options a year or so ago, the marketplace is starting to feel a little crowded. There is the Reveni, the Keks, Doomo (Chinese Voigtlander VCii copy), and a few others Chinese brands usually found on ebay… and possibly even more(?). All of these meters are designed to fit on the top of your manual film camera to offer a convenience of light metering that is somehow lost when using a smartphone app. All of them will no doubt have their pros and cons – though I can so far, out of these new meters I can only really comment on the Hedeco and Reveni.

Comparing the two, it’s hard to say which one is outright “best” – the Reveni wins out for its small size which will forever win it favour with me, but the speed of operation the Hedeco brings to the table will definitely win it fans with faster working photographers. Which one would be right for you, is going to come down to personal taste. I must admit, I am quite taken with this little Hedeco Lime One light meter though – I could certainly make it work for me.

Of course, as to whether it will work for anyone else is a little moot at the moment, as it isn’t currently available to buy. The one I have here was sent to me to review to help promote the Kickstater which as I have said has just launched – though I should add, I do think it deserves to succeed. You can back the Hedeco Lime One here

Good luck, Johannes, and thanks for letting me see and play with your invention ahead of the launch!

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7 thoughts on “Hedeco Lime One Compact Light Meter Review and Launch on Kickstarter”

  1. The problem with only displaying a live reading, not locking it down, is that how do you know what you took a reading of? With meters that lock the reading, you put the camera to eye, frame, push the meter button which then lets you know what was metered.

    I really like the form factor and ISO range, perhaps Hedeco can give it live AND locked meter readings?

  2. Thanks a lot for this very informative article Hamish. It is always good to see, that there are still companies who try to make the live for analog photographers easier. No matter whether it is from Hedeco, Reveni or Voigtländer, everybody has to decide whether he wants to use it or not. When I am in the street with my M4, I use the sunny 16 or my very small Gossen Digisix 2. Or if I forgot the Goosen, a lightmeter app.
    I like the idea behind the shoe mount light meters, but I would not use them. The reason sounds stupid and it is for sure very subjective, but I think they disturb the classic esthetics of an analog camera. When I use such a camera, I am not in hurry, speed is not my main goal. I have time to use my external lightmeter, adjust my settings, done.

  3. For anyone reading this now it seems that the designer has improved the specifications.
    Firstly the shutter speed range now goes from 500 minutes to 1/8000 sec
    The aperture can range for f/0.7 to f/1024
    And the ISO can be set from 0.5 to 12800.
    Clearly that will be most important to pin-hole enthusiasts.

    Perhaps more interesting is that there is now a choice between continuous live readings and measurement only when pressing the button
    The Field of View is apparently 35 degs.


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