Isolight Reflective Test Chart Light Metering & Timing Measurement System

SKU: Isolight-Group

The Isolight light metering system combines four photopic light sensors, a 100-LED chaser display, a flexible chart holding system, and multiple mounting options. The Isolight can greatly accelerate image quality testing and enhance the quality of your imaging product.

  • Powered by USB, DC adapter, or 3 or 6 AAA batteries

  • Dimensions: 13.6in x 11.6in x 0.8in (345mm x 295mm x 21mm)

Lead time is approximately 3-4 weeks.

Availability: Available to Order.

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Isolight Reflective Test Chart Light Metering & Timing Measurement System

SKU: Isolight-Group


Color Sensors

The heart of each Isolight Color is its four RGB color sensors.  Each sensor is cosine-corrected and closely matches the standard CIEXYZ (human eye) spectral response.  Positioned at each of the test chart four corners, the color sensors measure illumination color, absolute light level, and illumination uniformity.  The sensors are always positioned near your test chart, so you never have to try to hold or mount a hand-held light meter in the scene again.

Color is reported as a correlated color temperature (in degrees K) or as Yxycoordinates.  The USB interface also reports color in Yu'v' colorspace.  Light level is reported in Lux.  By measuring both color and light level, you will be able to ensure your lighting is the best for your image quality calibration and testing needs.

Secure and Flexible Chart Holding

Isolight holds and protects your charts during use and storage. Your test charts are valueable and need to be protected from accidental damage.  Isolight is designed to hold standard test charts safely and securely.

Retractable Clips

Chart clip

Isolight includes a pair of retractable clips and a lipped shelf to keep charts flat and in place whether Isolight is mounted vertically, on a tripod, or on a table-top.   A thumbwheel rotates the clips out of the way for quick chart changes.  The clips also retract flush into the device surface for use with larger charts.

Isolight is compatible with many industry standard chart sizes

Isolight with CC

Color Charts


The Isolight System

Isolight with gray chart 

Gray cards

Isolight with Q14

Gray step charts

Isolight with OECF

OECF Targets

Isolight with SG

Other test charts

LED Indicators

Quickly verify light levels 

Isolight front profile

Customers and industry standards specify test light levels. Unfortunately, achieving the right lighting conditions is tricky and tedious. Using handheld light meters is difficult because of the chance of casting shadows and altering the lighting. Mounting a light meter near the test chart is better, but limits you to a reading at a single point - you still don't know the lighting uniformity. Even with multiple meters, measuring flatness and average light level is hard. Isolight solves all the problem entirely.

LED indicator montage

Isolight uses innovative LED indicator rings around each light sensor to show when the light level is too high, too low, or within target levels.  Users set their target light level in lux and uniformity in either lux or percent.

Isolight includes two indicator modes: level tolerance and uniformity tolerance

  • Level tolerance - light levels are judged as absolute readings in lux, with the upper and lower limits set by the user-selected tolerance
  • Uniformity tolerance - LED indicators report which sensors are above or below the specified tolerance level relative to the average light level. Uniformity mode is useful for ensuring the lighting is uniform, regardless of the current light level

Display Schemes

Several user-selectable display schemes are available:

Mode Too Dark Within Range Too Bright Comments
Red/Green/Yellow Red Green Yellow Good for general use
Red/Off/Yellow Red Off Yellow Ideal for production. LEDs are off when lighting is correct and only show if there's a problem
Slow Red Flash/Green/Fast Red Flash Slowly flashes red Green Slowly flashes red More visible in bright conditions

Brightness Controls

LEDs can be hard to see in bright light or cause light pollution in very low light. Isolight offers manual brightness control as well as an innovative auto brightness mode. In auto brightness mode, the LED brightness automatically adapts to the current average scene brightness, so that the LED indicators are always visible but not so bright as create light pollution and distort the scene lighting or affect camera performance.

Audio Indicators

Isolight also features audio feedback to indicate when the lighting is correct. When enabled, Isolight plays distinctive tones when all four sensors are within range or when any of the sensors go out of range.

LED Chaser Display

While currently unsupported, Imatest will soon support the integration of data gathered from the LED Chaser into it's results.

Measure time-related performance parameters

LED ChaserIsolight includes a 100 LED chaser display.  Simple in operation, the LED chaser lights each LED in sequence.  Each LED stays on for a user-settable time period.  The LED chaser can be used to measure a wide range of time-related imaging parameters. 

Measure from Milliseconds to Minutes

The LED chaser step time is programmable from 0.1ms per step to 1.0 second per step. The total display cycle time is from 10.0 ms to 100 seconds. You can easily measure the fastest single frame exposures all the way to minute-long exposures or video clips.

Emphasis LEDs for Easier Counting

Counting a lot of LEDs is tedious.  To make the process faster and more accurate, Isolight features an optional LED emphasis mode.  The emphasis mode makes every fifth, tenth, or 33rd LED noticeably brighter, so that it stands out.  The emphasis LEDs let you quickly count blocks of LEDs the same way tick marks on a ruler make measurements easier.

Auto LED Brightness

Similar to other Isolight components, the LED chaser LED brightness can be set either manually or automatically adapt to ambient light levels.  The "auto" mode adjusts the LED brightness so that the LEDs are clearly visible at any light level but not so bright as to introduce light pollution. 

Audio Output for Audio/Video Testing

Isolight can also generate audio markers (beeps) synchronized with the LED chaser operation. Audio markers can be generated at the start of the line, for every emphasis LED, or for every LED.

Measuring Still Image Time Parameters

  • Exposure Time - the most basic measurement.  Set the LED chaser at an appropriate step rate and capture an image.  By counting the number of lit LEDs, you can measure the image's exposure time.

Measuring Video Image Time Parameters

  • Frame Rate - Set the LED chaser so that several LEDs are visible in each image.  The frame rate is the number of LEDs from the start of the bar in one image to the start of the bar in a second image
  • Frame Rate Jitter - the frame time from one image to the next should be constant.  If the frame rate varies more than one LED, there is significant frame rate jitter in your system
  • Dropped Frames - Every LED should be visible in at least one video frame.  If any LEDs are missing from the sequence, your system is dropping frames.  You can estimate the drop-out period as well
  • Audio/Video Synchronization - Audio/video track synchronization can be measured by capturing video with audio markers enabled for emphasis LEDs. Each audio marker should sound during the associated video frame. The amount of leading or lagging indicates the audio track desynchronization
  • Auto-Exposure Behavior - Using the auto LED brightness mode, you can watch the exposure time change from frame to frame as you adjust the light level.  This is very useful for measuring and auto exposure convergence time, stability, and over/undershoot.

LCD Display Modes

Isolight provides many LCD display modes to show just the information you need.  Easily switch display modes with the UP and DOWN keys.

Display Modes

LCD 4x readings

Large Average Reading

Best for low resolution cameras and basic operation
2x bars

Large Readings

Large individual readings show the level at each sensor
Reading details

Reading Details

Shows light details including average level, current uniformity, target high and low levels, and individual sensor readings
Reading bars

Level Bar Graphs

Auto-scaling horizontal bar display of individual levels with reading details
Tolerance Bars

Tolerance Bar Graphs

Horizontal bar display of levels relative to tolerance target.  Central arrows indicate the target level for each sensor
Chaser details

LED Chaser Display

Shows all LED chaser settings
LCD combo

Combination Display

Combination of readings, target and tolerance data, and LED chaser settings


Auto Backlight Brightness

Like the LED indicator rings and LED chaser, the LCD backlight brightness can be set manually or used in auto brightness mode. Auto brightness mode uses the ambient light level to adjust the brightness for optimum viewing in very dark or bright conditions. It also ensures the backlight doesn't introduce light pollution by being too bright in low-light conditions.

Programmable Presets

PReset buttons

Industry image quality standards and customer specifications usually require image quality testing be done at a few specifc light levels.  Isolight includes four programmable preset buttons to easily save and restore the entire device state so that you can quickly switch between lighting conditions and system set-ups.


Saving and Recalling Presets

The preset buttons use a simple press/hold interface.  To recall a preset, simply briefly press the appropriate button.  A short success beep will confirm your request if a preset was saved.  If no preset is saved, an "error" tone will play.  To save a preset, simply press and hold the appropriate key until a confirmation tone plays.  

Presets are non-volatile and are saved between power cycles and even if power is completely lost. 

Remote Operation

Remote Data Acquisition and Control

USB Port

USB Interface

Isolight features a USB interface for remote control and data acquistion.  The simple command language provides access to all menu command settings.  All light sensor data is available including individual sensor readings, current target value, and min and max tolerance values.

XBee Wireless Interface

Isolight also offers an optional XBee wireless interface.  Using the same command language as the USB interface, the wireless interface is easy to set-up and means one less cable to manage whether in a light booth, studio, or in the field.

Production Test Systems

Isolight is ideal for use in production test systems to ensure accurate and repeatable set-ups.  Use Isolight to automatically verify lighting is operating and configured correctly.   


Mounting Options

Once your chart is safely mounted in an Isolight light meter, you need a way to support the Isolight.  Fortunately, there are many options.


Tripod back mounting

Bottom tripod mounting

Tripod Mounting

The back surface and bottom edge have a 1/4"-20 threaded hole for tripod mounting

Isolight fold-out legs

Fold-out Legs

A pair of built-in, fold-out legs allow Isolight to be set-up on a table surface like a picture frame.  The legs fold down flush with the back surface.  The legs are great for use in non-magnetic light booths, customer sites, or at tradeshows

Keyhole slots

Keyhole Slots

Three keyhole slots in the back allow Isolight to be mounted on walls like a picture frame

Application Examples