Isolight Reflective Test Chart Light Metering & Timing Measurement System
Isolight Reflective Test Chart Light Metering & Timing Measurement System
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.
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
The Isolight System
Gray step charts
Other test charts
Quickly verify light levels
|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|
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.
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
Isolight 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.
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.
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 Data Acquisition and Control
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.
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 MountingThe back surface and bottom edge have a 1/4"-20 threaded hole for tripod mounting
Fold-out LegsA 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 SlotsThree keyhole slots in the back allow Isolight to be mounted on walls like a picture frame
- In a Light Booth
- In the Studio
- Field Testing
- Standards Testing
- Video Testing
- Customer Demos
- At Trade Shows
- Production Test Systems