ColorHug+ Introduction

For artists, photographers and animators it's often essential to be working with an accurately color calibrated screen. It's also important to be able to print accurate colors being sure the hard copy matches what is shown on the display.

The original OpenHardware ColorHug device provided an inexpensive way to calibrate some types of screen, and is now being used by over 2000 people. Due to limitations because of the low cost hardware, it does not work well on high-gamut or LED screen technologies which are now becoming more common. ColorHug+ is a new device designed as an upgrade to the original ColorHug. This new device features a mini-spectroraph with UV switched illuminants. This means it can take spot measurements of paper or ink which allows us to profile printers and ensure we have a complete story for color management on Linux.

I've been working on-and-off on the ColorHug+ for the last year in my spare time (and those with young children know why I'm so behind schedule...). I'm now at a point where the device specification is more-or-less defined, sensors chosen, and I've got a space model and electrical prototype. We need to work out if there is significant demand for the ColorHug+. If I don't get at least 100 pre-orders it's not going to be economically viable to continue development. I posted a longer cost analysis to the mailing list if you're curious for the need of 100 pre-orders before proceeding.

We don't have any glossy renders of the finished designs but this will hopefully come in due time. I'll post a lot more photos of the prototypes when I'm not ashamed of how hacky everything looks, but the device is likely to look very similar to the original ColorHug albeit twice the size.


Specification so far

  • 5nm optical resolution
  • 2nm electrical resolution
  • High CRI user-replaceable "burnt-in" tungsten illuminant
  • DAC controlled UV LED user-replaceable illuminant (for FWA measurements)
  • 0.125 degree temperature compensation
  • Fixed slit size (exact specification tbd)
  • Black ABS box with gaskets suitable for display, paper and printer calibration (ambient add-on to be designed later)
  • Individually calibrated CT spectrograph with spectral peak data and wavelength absorption
  • A RGB status LED that shows status and optionally the approximate color of the measured sample (for a visual indication only)
  • A USB protocol that allows you to access the realtime spectra, or just a simple absolute XYZ value for a swatch
  • Support in libcolorhug and colord, and hopefully also ArgyllCMS
  • HugStrap for display measurements
  • LiveCD with updates
  • Bi-monthly firmware updates with new features and bugfixes
  • Access to upgrades for early adopters like before. (This is likely to involve "better" illuminants, perhaps an upgraded PCB, case etc.)
  • A cardboard shipping box with free worldwide signed-for shipping

A chance to preorder

At this point I am asking people to preorder for the ColorHug+ with a suggested RRP of maximum £300.

So, if you are fairly sure you'll want to buy a ColorHug+ in about 9 months time (although it's not legally binding, and you can cancel whenever) then could you please send an email to info@hughski.com with [preorder] in the subject. Please note if you preorder - we DO NOT want any payment or your address/phone number. If you've got any questions, concerns or are just delighted beyond words, please send an email to the colorhug-users mailing list.


How do the different devices compare?

  ColorHug ColorHug+
Display Calibration [yes][1] [yes]
Printer Calibration [no] [yes]
Spot Measurements [no] [yes]
Output deviceRGB, absXYZ Full 400-780nm spectra, absXYZ
Technology Tristimulus colorimeter Czerny-Turner spectrograph
Price £60 + postage £300 (free worldwide signed-for postage included)
Size 32x43x21mm 75x75x32mm
Expected User Consumer artists and photographers Professional artists, prosumer photographers and color scientists
Availability Over 2200 sold with stable firmware A prototype exists
Free updates for early-adoptors Firmware, new screen gasket, HugStrap Nothing yet, but likely Firmware, PCB, illuminants, case

[1] Only devices with primaries close to sRGB, or with a CCMX file.