Lime One

Lime One is a compact Light meter for analog cameras.

a compact light meter

A reflective light meter for manually controllable cameras that don't have a meter integrated or have one that is no longer working.

usabiltity first

  • aperture priority, shutter priority, manual, exposure value modes
  • fast operation and start up, stored previous settings
  • set parameter quickly using a control wheel
  • change secondary parameters by holding the button when turning the wheel

engineered for longevity

  • anodized aluminium body and control wheel
  • uses the standard accessory shoe mount
  • standard CR2032 battery used in many devices

how to

The how to clip below explains the workflow in aperture priority mode.

The tabs A S M EV show how different modes are effecting the display and calculation. The camera pans from a darker (left) to a brighter (right) area.

aperture priority: f-number is set and the shutter speed is calculated
shutter priority: shutter speed is set and the aperture f-number is calculated
manual mode: f-number and shutter speed is set and the exposure offset is calculated
exposure value: shows the exposure value, compensated for ISO and EV offset.


size 43x30,5x15 mm
weight 16 g
battery 3V CR2032
aperture f0.7 ... f1024
shutter speed 1/8000s ... 8 hours 20 minutes
ISO 0.5 ... 12800
stepsize 1/3 stop (optionally 1 stop)
dynamic range
(@ISO 100)
-3* ... 20 EV
*: Below 0 EV usable, but having a lower resolution, more noisy signal

Field of view:
(approx. 50mm lens, center weighted)

operational modes:

parameter A S M EV
primary (wheel) f-number shutter speed shutter speed exposure comp.
secondary (wheel+button) exposure comp. exposure comp. f-number ISO
calculated result shutter speed f-number exposure comp. exposure value

See the download section for PDF downloads

exploded view:



My name is Johannes Heberlein, I am a mechatronics engineer and created the Heberlein Design Company - HEDECO to bring my personal projects to life. After years of tinkering and publishing open source projects (e.g. plotclock / thingiverse) I decided to develop some of my projects for the consumer market in the style of a small batch business . While working primarily on my own, for manufacturing and some engineering I partner with local businesses around the Nuremberg metropolitan area. Johannes Heberlein

Order information

Updated: 21. July 2021
Because of supply chain issues and production yield I currently do not offer preorders and will only offer devices once they are ready to be shipped.

Availability road map: The first round of orders in August will be made available only to the subscribers of the newsletter for availability. To be as fair as possible I will limit the order quantity to one meter per order and give people who already subscribed in 2020 advance notice.

Prices will be 139€ for the standard silver version, 159€ for the silver or black version including accessories. Standard shipping will probably be between 6€ (Germany) and 15€ (international)


Josephspl. 8
90403 Nürnberg
Represented by: Johannes Heberlein

Register entry
Entry in: Handelsregister
Register Number: HRB 37837
Register Court: Nürnberg

UST-IdNr.: DE332934803

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PDF downloads

3D printable accessories