A survey of 300 people was conducted recently to compare the images of four different unmarked projectors using different solid state lighting technology. The survey examined if a new LED-based light source developed by Philips Lighting would be bright and colorful in a normally lit room and if the images might be preferred by the survey participants. The answer to both questions was yes.
Details of the test set up, calibration, test images, survey questions and results are all contained in a white paper prepared by Insight Media. You can download the white paper by clicking button.
The new solid state light source, called ColorSpark High Lumen Density, or HLD, is a breakthrough in LED lighting technology. LED projectors to date have had limited lumen output due to the inability to couple enough light onto the imager. The new design breaks through this barrier allowing LED projectors in the 2000-4000 mainstream lumen range.
And just as importantly, the images are now visible in a normally lit conference room using a standard matte white screen (100-150 ambient lux from top to bottom of the screen with identical 80” images on the screen). Overall, 68% survey participants preferred the picture quality of the HLD projector vs. the other options.
To do the testing, Philips chose three other projectors from leading brands to benchmark their new ColorSpark HLD LED technology against. These were chosen to represent the three different types of solid state illumination sources available in mainstream projection solutions. Commercial, off the shelf projectors representing popular examples of the representative solid state illumination technology were purchased.
The test projectors were placed under boxes and only identified by a letter:
- A – RGB LED projector
- B – Philips modified projector – ColorSpark HLD LED light source
- C – Laser phosphor projector
- D – Hybrid (LED and Laser) projector
Survey participants were told to first carefully evaluate the 15 images that displayed in a loop, then to fill out the survey. Participants were then asked to rank the projectors (A, B, C or D) for:
- Highest apparent brightness
- Color accuracy (colors are true to life)
- Most pleasing colors (image looks best with these colors)
- Best contrast (details are crisp and clear in the darker and brighter regions)
- Overall picture quality (combination of contrast, colors and brightness)
The results were quite interesting with results for the men, women and colorblind participants broken out in the white paper. For all questions, the ColorSpark HLD LED projector scored highest. The results are shown in the table below. Note that all the projectors were set to the sRGB mode which is supposed to be the most color accurate mode.
Summary of Results
Additional details of the survey along with a discussion of the results, is available in the white paper.