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Decent exposure (4): The brand new Hedeco Lime Two light meter and one of its ancestors from Nürnberg

Image shows light meters Hedeco Lime Two and Gossen Polysix
Don’t waste expensive film to bad exposure: The new Hedeco Lime Two light meter (on the M3) or the old Gossen Polysix can be helpful.

Your camera doesn’t have a light meter, or the light meter doesn’t work anymore? No problem, there are attachable light meters for the hot shoe. The Hedeco Lime Two is new and excellent. And it’s made in Nürnberg, exactly as the Gossen Polysix electronic 2, an almost forgotten hand-held meter which, cum grano salis, is one of the great-grandparents of the Hedeco.

As we all know, decent exposure is a key requirement for a good photograph. While modern cameras have excellent automatic metering and exposure control, there was a time when light metering was an art. And external light meters are still made today, as I demonstrate in my three-part series called Decent Exposure. Read here in part one about attachable light meters, get more information about handheld meters in part two and read here in part three about the pros and cons of light meter apps for your smartphone.

Hedeco Lime Two: innovative and maybe a future modern classic

And there are innovations in the market. Clever people launched several projects successfully in recent years. One that went particularly well was Johannes Heberlein’s. He ran a great Kickstarter campaign for his HEDECO Lime one (Hedeco: Heberlein Design Company; Lime: light meter) and released a very small and easy-to-use shoe-mounted light meter in 2020. The Lime Two is available from February 2023. It retains all the virtues of the first version and adds some great improvements.

From the Leicameter to Kickstarter projects

The idea of a shoe-mounted light meter is not new, but the concept has undergone a major makeover. In a way, all these projects are derived from the Leicameter, which was made by Metrawatt, also in Nürnberg. However, none of the new light meters has the mechanical coupling of the Leicameter. While this is a disadvantage in use with Leica cameras, it does allow for much smaller designs that you can also attach to many other cameras.

Hedeco Lime Two is available for Hasselblad and Rolleiflex

The Hedeco Lime Two is excellent in this respect. Heberlein offers a range of adapters for attaching the Lime to cameras without a hot shoe, such as the Hasselblad 500 series or the two-eyed Rolleiflex, or cameras that require a spacer between the hot shoe and an attached accessory. All these add-ons are 3D printed (in good quality), and Johannes Heberlein generously offers the design files on an open-source basis.

All-metal now: seven grams make quite a difference

The Lime Two’s biggest improvement over its predecessor, in my opinion, is its all-metal body. Remember, the somewhat fragile appearance was my biggest criticism of the Lime One, which was made partly from thin aluminium and partly from 3D-printed plastic. The new version is now made from machined solid aluminium. It is a little heavier (23 vs 16 grams), but the other dimensions are almost identical (40.5x28x11mm without the hot shoe). The look and feel is simply stunning now!

Put the Hedeco Lime Two on a high-end camera; nothing looks cheap or amateurish

What’s also new on the mechanical side: The hot shoe (now made of high tech machined POM aka Polyoxymethylen Copolymer material* instead of cheaper plastic) can be attached in a number of positions to ensure that the camera’s controls are not obstructed. The battery compartment (a long-lasting standard CR 2032 lithium cell) is also more solid. All in all, a nice piece of engineering that looks good on a high-end camera of whatever vintage.

* In an earlier version, I wrote the shoe was made of metal. POM feels much more like metal but is a synthetic material in fact. Johannes Heberlein correctly points out that it causes much less wear on your camera that an metal part. Another proof how well designed the Hedeco Two is)

The same good operation, with small but significant improvements

The electronics have also been improved. Fortunately, the designers retained excellent single-button, single-wheel operation. So, the only thing you must remember is that a double click opens the menu; everything else is self-explanatory. A new feature is an ability to select full, half and third stops — separately for shutter speed and aperture! That’s brilliant; imagine a camera with full shutter speeds combined with a lens that offers a third of a stop for the aperture. And you can choose between the modern scale based on 1/60th of a second and the historic scale based on 1/50th of a second. Good news, for example, for owners of early Leica M3 models.

The only thing to keep in mind for Hedeco Lime Two users: double click opens the menu

The menu has also become a bit more intuitive, and the OLED display is now a tad larger. It still shows a manually set exposure compensation both in +/- f-stops and as a graph. The displayed compensation range is plus three to minus three stops and can be extended to +/- 9 stops*. The total range of the Hedeco Lime Two is from -3 to 20 EV, which should be sufficient for most types of photography (below 0 EV, the resolution is lower, according to Hedeco). 

*clarification based on feedback by Hedeco

Shutter speed, ISO and aperture can be set and displayed in a very wide range. You can also enter a global calibration setting, but this was not necessary on my copy, as the comparison with my reference meter, the Sekonic L-758D, showed. By the way, you can also switch the Lime Two between continuous and memory measurement via the menu. What more could you ask for?

Hedeco Lime Two creator says: Analogue renaissance triggers demand

Although the market for attachable light meters is now quite crowded, as Hamish Gill points out in his review of the Lime Two, Hedeco seems to be a successful project. Johannes Heberlein told me that he decided to make a completely new version of the Hedeco instead of an update because he wanted to respond to the feedback of his customers in the best possible way. These are mainly rangefinder users, LTM and M-mount Leica, but also Canon P. Heberlein sees an analogue renaissance and hopes for a further increase in interest but is also a little concerned that the material might become too expensive (one more reason not to waste a single shot by over- or underexposing, I would say).

If the wheel-and-button concept suits you, look no further

All in all, the Hedeco Lime Two attachable light meter is excellent in this second iteration. It seems to have overcome the minor weaknesses of the Lime One while retaining all its many advantages. If you are looking for a modern, easy-to-use, accurate and attractive light meter to attach to your camera, this is the way to go. You can buy the Lime Two in black or silver directly from Hedeco for €149; adapters are additional and cost between €3.90 and €7.90.

Gossen Polysix electronic 2: innovative and almost forgotten

Only a few kilometres from Hedeco’s base in Nürnberg is Gossen Foto- und Lichtmesstechnik, a company with a long-standing reputation for light meters. Gossen continues to produce light meters for photography, but the heyday was in the 1950s to 1970s with iconic models such as the Sixtomat, Profisix and Lunasix. Less prestigious is the Polysix, but with its pragmatic design and its clever features, you could call it one of the forefathers of the Hedeco.

Wow, object metering with three different angles

There are decades between the two light meters: According to Camerawiki, the Polysix/Variosix (name depending on the markets) was introduced in 1968, and the Polysix electronic 2 is from the early 70s. It is unusual in that it is a zero-based design, allowing constant accuracy over the entire metering range. And it offers object metering, including selective metering at 10°, 20° and 30° angles, as well as light metering by means of a small plastic sliding dome. 

No hassle with hard-to-find batteries

Uniquely, the Polysix has an optical viewfinder for selective measurement (the smallest circle is 10°, the middle is 20° and the full circle 30°). Another pragmatic way of integrating an important function without making the design and operation of the light meter too complicated. Finally, the Polysix’s CdS cell-based electronics deserve special mention for using two standard AA cells, making it future-proof. Many other light meters were based on the now discontinued 1.35-volt batteries.

The veteran is reliable but a little slow

In practice, the Polysix is very good and accurate, if a little slow. It can take a moment to get a correct reading, and switching between the low and high light ranges takes some getting used to. I can only recommend reading the manual. It is indeed a small, precise and understandable introduction to the basics of exposure. A little gem in its own right, even in its wonderful 1970s layout. Another parallel to the Hedeco: The manual of the Hedeco Lime Two is also more than just a description of the light meter, but gives a very good basic overview of working with light.

For the Hedeco Lime Two and the Polysix, manuals are truly instructive

Speaking of manuals: Hedeco offers them for download (a printed copy in English is included in the vintage-style box), a good source of information if you have doubts about whether or not the Hedeco Lime Two is right for you. Gossen, in turn, has many manuals for discontinued models on its website: That’s decades of customer service. Thanks to all at Gossen. May other manufacturers take a leaf out of their book.

Hedeco Lime Two and Gossen Polysix: two answers to the same question

Two light meters from Nürnberg, Germany, about 50 years apart, but built with the same idea in mind: to help photographers select the right exposure. Two answers to the same question, two of many possible solutions, of course. What these two light meters have in common is, of course, not just that they come from Nürnberg. They are both fascinating in their own right. And both combine tradition and modernity in their respective contexts. In this respect, the Hedeco Lime Two is in a great historical line and can keep up very well. 

Hand-held or attachable? It depends…

Whether you prefer to use a vintage hand-held exposure meter such as the Polysix electronic 2 or a modern miniature shoe-mounted meter like the Hedeco Lime Two depends on the scope of the task and individual preferences. The Hedeco Lime Two supports exclusively object metering, whereas most handheld meters are also capable of light metering.

In conclusion, I can wholeheartedly recommend the two devices that I decided to present here as a formerly unplanned part of the “decent exposure” series of light meters. A good Polysix can be found on the second-hand market with a little patience, while a new Hedeco Lime Two is just a mouse click away. In any case, both are a great way to bring an analogue gem back to life!

Disclaimer: Hedeco offered me a review copy of the Lime Two on loan, but I finally decided to order and buy it for future frequent use with my analogue cameras. The Polysix was indeed a flea-market find and primarily intended for my small collection — but it turned out to be surprisingly useful. I am working on an entirely independent basis, and I neither seek nor accept gifts or discounts in exchange for a favourable verdict, link or mention of brands or products.

Decent exposure: The Macfilos mini-series about light measuring solutions

Part 1: Why light meters are useful or necessary and which camera-attachable light meters are recommendable (with reviews of Leicameter MR, Voigtländer VC Meter II, KEKS EM-01, Hedeco Lime One and TTArtisan Two Dials exposure meter. You can read this article in German here on Messsucherwelt.

Part 2: Why incident light metering is better and what other advantages hand-held light meters have (with a review of five hand-held light meters: Gossen’s Lunasix F and Variosix 3, and Sekonic’s Twinmate L-208, Studio Deluxe L-398A, and L-758D (if you prefer this article in German, find it here on Messsucherwelt).

Part 3: How you can work with a light meter app for your smartphone and which chances and risks you have to know (with reviews of MyLightmeterPro, Lightmate, Lghtmtr, Luxi and Photometer). Plus: The complete overview of all 15 tested solutions (again, there is a German version on Messsucherwelt).

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  1. I have used all types of meters including Sunny 16 and just plain old guesswork. I have had various ones over the years including the Voigtlander two dials models. The small one you show here is admirably compact, but you have to be very careful about where you point the camera when taking a reading. I have also used a Gossen DigiSix where you transfer a digital EV number to a wheel, which will show a choice of a range of shutter speed and aperture options which I really like. I much prefer this to a digital read out, the same way that I prefer shutter dials on cameras and aperture rings on lenses. The battery in the Gossen keeps running down, so I have just bought a Sekonic L398 A III which has no batteries, just an Amorphous Photocell. Everything on it is perfect. You can see exposure options and even do exposure compensation with it. There is no fussy pressing on buttons for ISO etc. It has a powerful magnet in it so you have to be careful where you place it and is larger than the DigiSix, but it comes with a nice neck strap. So far it matches my cameras with meters exactly. For newcomers the manual does not show how to use the cones and do incident and reflected readings, but there is plenty of material online about this. I will start using it seriously for film photography when I get my new glasses in a few weeks time.


    • Thank you, William,

      for your ever knowledgeable feedback. In fact, it takes some practice to work with the small attachable light meters. The Hedeco Lime Two has a ≈35 degree angle of measurement which considerably reduces the risk of a completely wrong readout. On the other hand, it can’t match te precision of a masterful spot measurement. I still miss the built-in multispot metering of the Olympus OM-4. This was the best I ever saw in a film camera.

      I fully agree on the Sekonic L398AIII but make sure you keep it away from mechanical watches, credit cards, smartphones and digital cameras. The built-in magnet is really powerful. I am sure you will get great results with it because you know how to work such an instrument.

      I generally also prefer analogue readout (be it on a watch or a camera) but for a digital solution, the Hedeco Lime Two is great. It will help many beginners to get their exposure right. It is the best attachable light meter I have seen so far and costs half of the low-tech Voigtländer one. My all-time favourite, however, is the small Sekonic Twinmate L 208. Runs for years on one battery, can be used for object and light measurement over a wide bandwidth and is affordable. See here in part 2 of “Decent exposure”: https://www.macfilos.com/2022/05/20/decent-exposure-part-2-hand-held-light-meters-and-what-they-are-good-for/

      All the best, JP

  2. Thank you for this very carefully researched set of articles! Quite a lot of work, but a massive amount of informtion.

    I keep reading that the modern digital Leica cameras have a built in light meter. But it’s not quite the same is it? I wonder if I might get more information mounting one of these on my M240!

    • The internal meter of a digital camera will be more accurate than an external meter because of through the lens metering (TTL). In older analog cameras TTL metering is preferable if available, though an external meter might make sense if the calibration seems off or if replacement batteries induce an error, for example when using a substitute for batteries that contained mercury.

    • Hi Kathy,

      as Johannes wrote: The TTL metering of you camera will be more accurate than the use of an attachable light meter. That’s due to the principle and NOT caused by quality/precision issues of a Hedeco Lime or the like. Your M240, as a digital camera, has a built-in light meter of course, and you will get used to its pecularities over time (it is very much center-weighted).

      An attachable light meter makes sense if your analogue camera has no or no working light meter. A hand-held light meter, however, is another kettle of fish and can be useful even for work with the latest and greatest digital cameras because you can use the method of light measuring (as opposed to object measuring. See part part two of my “Decent Exposure” series, it’s explained there: https://www.macfilos.com/2022/05/20/decent-exposure-part-2-hand-held-light-meters-and-what-they-are-good-for/

      Best wishes, JP

  3. Interesting read. As always. I might consider a Hedeco Lime Two for my Hasselblad. As far as the analog renaissance is concerned I hope it continues and that it will not be brought to a halt by a rumored significant increase in film prices (by Kodak).

    • Good idea, SlowDriver, the Hedeco Lime Two will save you considerable amounts of increasingly expensive film. You almost can’t afford a bad exposure anymore unless you are working on b/w and process your film on your own. I also see the price explosion for film material with some concern but if Kodak streches it too far, I hope, there will be competition. JP

    • Thanks, Richard, for your kind feedback. Maybe you need a light meter one day and find advice in the “Decent Exposure” series. JP


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