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SEKONIC LD

The Dream Tool for Lighting Designers because Illumination Matters


The C-4000 offers a compact, lightweight, sophisticated, and affordable solution for the lighting professional. The measurement screen specializes in basic functions, and displays the values ​​essential for light measurements, such as illuminance, color temperature, ⊿uv, color rendering properties (CRI, TM-30), and chromaticity coordinates (x, y), allowing you to quickly check the values ​​on site. In addition, you can connect the meter with the dedicated app, SEKONIC LD, via Bluetooth. The app enables you to remotely trigger measurements, display numerical values and intuitive graphs of measurement results, and import stored data from the C-4000 on the smartphone/tablet screen.

・Displays various measured values ​​such as illuminance, color temperature, ⊿uv, color rendition, etc.

・Remote operation and graph viewing are possible with the dedicated app, SEKONIC LD

・Compact and simple body for easy handling

・Easy-to-read LCD specialized for numerical display

矢印  Purpose of use

・Illuminance, color temperature, and color rendering evaluation of various architectural lighting

・Lighting management in museums, office environments, commercial facilities, etc.

矢印  Recommended customers

・Lighting designers, lighting installers, people who manage light sources of museums, restaurants, interiors, etc.

・People engaged in quality control or research of LED, organic EL, projectors, etc.

・People who manage light sources for photography or research.

  • Art museum
    Art museum
  • Museum
    Museum
  • Restaurant
    Restaurant
  • Gallery/Showroom
    Gallery/Showroom

Feature

矢印  Measurement screen specialized for necessary basic functions

The C-4000 uses a touch panel LCD, displaying illuminance, color temperature, ⊿uv, color rendition, and CIE1931 chromaticity coordinates. The LCD can display four types of items at one time.
Once select the item that suits your purpose, you can instantly check the information you want to know.
Up to 99 measured values ​​can be saved.
  • Measure screen
    Measure screen
  • Display Item Library Screen
    Display Item Library Screen

・lux... Illuminance (lx)

・Tcp... Color temperature (K)

・⊿uv... Color deviation

・Ra... Average color rendering index

・Rf... Color fidelity (TM-30)

・Rg... Color vividness (TM-30)

・x･･･ CIE1931 chromaticity coordinate (x)

・y･･･ CIE1931 chromaticity coordinate (y)

矢印  Compact size, easy to handle

The C-4000 achieves accurate spectroscopic measurements despite its compact size. Its structure is quite simple with only two physical buttons (power button and measurement button).
The small body is easy to handle. In addition, the left side is equipped with a USB Type-C connector.
You can update the C-4000 firmware by connecting it to a PC via USB and using utility software.

矢印  Measure, record, and report effortlessly with the all-in-one solution

You can enhance the ease of use by installing the app, SEKONIC LD, on your smartphone/tablet and connecting it to the C-4000 via Bluetooth, which enables you to perform remote measurements. You can check the measurement results on the app screen using numerical values and more intuitive graphical displays. Not only can remote measurement results be shown and saved on the SEKONIC LD, but it is also possible to transfer measurement data saved on the C-4000 to the app for display and storage. Furthermore, by upgrading the app to the paid version, you can use various functions that support the workflow of lighting measurement, from measurement and recording operations to report creation and data sharing.
SEKONIC LDicon
[The app for the C-4000]
 SEKONIC LD
[Recommended environment] iOS 16.0 or later/Android OS 11.0 or later
SEKONIK LD

[Basic functions (included version)]

・Remote control of the C-4000 from a smartphone/tablet

・Import data from the C-4000 memory to a smartphone/tablet

・Various graph displays

・In-app data storage

・Status information display for the C-4000

・Supports 6 languages (English/German/French/Spanish/Italian/Japanese)

Various graph display
  • Spectrum

    The Spectrum displays the spectral distribution of the measured light source in a graph with a percentage of relative intensity and the wavelength. The graph can be viewed and saved via the SEKONIC LD.

  • CIE1931

    CIE 1931 color space is based on the tristimulus values that are mathematically derived from color measurements, representing red, blue and green light and theoretically represent the standard observer’s eye. The values of CIE 1931 are denoted by x and y coordinates.

  • CRI

    The Color Rendering Index (CRI) measures the ability of a light source to reveal the colors of objects in contrast to a natural light source, such as the sun. Ra averages R1 to R8 out of the 15 CRI values, providing a general assessment of the light sources’ color capabilities.

  • TM-30-18

    Published by IES (Illuminating Engineering Society), TM-30 is a color rendering index system that indicates how well a light source will reproduce a color accurately when it illuminates that object (as compared to a black body radiator – such as the sun).

[Advanced functions (in-App purchase)]

・Plotting measured values on drawing/photo

・Adding photo and memo to a measured value

・Linking GPS location information

・Automatic report generation

・Share reports and measured values ​​using the smartphone communication function

・Data management for each project

・Detailed settings such as selection of measurement items displayed on the drawing

Automatic report generation
  • Report of measured value plotted on the drawing/photo
  • Report of GPS data acquired at the measurement location
  • Report of measured value list

  • Report of measured value with graph and on-site photo

矢印  Techniques to make measurements more convenient

By using the C-4000 holder (under development) and a commercially available monopod, measurements in hard-to-reach places become more convenient.

* Be careful not to swing the C-4000 or hit it against the floor or wall.

矢印  Names of parts

矢印  Specification


Illuminance meter class JIS C 1609-1:2006 for General Class A Illuminance Meters Equivalent (excluding oblique incident light characteristics)
DIN 5032 Part 7 Class C Equivalent (excluding oblique incident light characteristics)
Light receptor element CMOS linear image sensor
Measurement wavelength range 380 nm to 780 nm
Measurement range *1 Illuminance: 5 lx to 10,000 lx (0.46 fc to 929 fc)
Color temperature (Tcp*2): 1,600 K to 40,000 K
Accuracy (Light source A) Illuminance: ± 5 % ± 1 digit (5 lx to 3,000 lx), ± 7.5 % ± 1 digit (over 3,000 lx)
x, y: ±0.003 (800 lx)
Repeatability (2σ, Light source A) Illuminance: 1 % + 1 digit (30 lx to 10,000 lx), 5 % + 1 digit (5 lx to 29.9 lx)
x, y: 0.001 (500 lx to 10,000 lx)
x, y: 0.002 (100 lx to 499 lx)
x, y: 0.004 (30 lx to 99.9 lx)
x, y: 0.008 (5 lx to 29.9 lx)
Spectral response characteristics (f1') 9 % or less
Oblique incident light characteristics (f2) 12 % or less
Temperature characteristics Illuminance: ± 5 %
x, y: ± 0.006 (Light source A, 1,000 lx)
Humidity characteristics Illuminance: ± 3 %
x, y: ± 0.006 (Light source A, 1,000 lx)
Power Supply AA battery (1.5V) × 2, USB bus-power
Measurement time Max. 10 sec, Min. 0.5 sec
Display value Illuminance (lx), Tcp*2 (K), ⊿uv, CRI (Ra), TM-30 (Rf, Rg), Chromaticity coordinates (x, y)
Other functions Data memory up to 99 items, Auto power-off, Auto dimming
Language Selectable from English, French, German, Italian, Spanish, or Japanese
Interface USB connector (type C), Bluetooth
Operating temperature 5 deg. C to 35 deg. C, without condensation
Operating humidity 85 % or less (at 35 deg. C), without condensation
Transportation and storage conditions -10 deg. C to 60 deg. C, 85 % RH or less (at 35 deg. C), without condensation
Dimensions Approx. 62 mm (width) × 140 mm (height) × 30 mm (depth)
(excluding protruding part of light receiving)
Weight 140 g (without batteries)
Included accessories Light receptor cap, Soft case, Strap
*1: "Under" is displayed when the illuminance is less than 5 lx (0.46 fc) or the Tcp is less than 1,600 K, and "Over" is displayed when the illuminance is over 10,000 lx (929 fc) or the Tcp is over 40,000 K.
*2: Tcp is Température de Couleur Proximale (Correlated Color Temperature).
Features and Specifications subject to change without notice.

矢印  Special parts and accessories

Name Included as standard item
Startup Guide Yes
Soft Case Yes
Light Receptor Cap Yes
Battery Cover Yes
Strap Yes
Operating Manual No. Please download it on our website.