While native 4K resolution is commonplace in flat panel displays, there are still many resolution options when choosing a projector, including WXGA (1366×768), WUXGA (1920×1200), 1080p (1920×1080), and various options to achieve 4K (3840×2160). As an alternative to the high cost of using native 4K chipsets, many projector manufacturers offer a form of “pixel shifting” to achieve 4K resolution on the screen. To add to the confusion, manufacturers have their own terms to describe this feature, including 4K Enhancement, 4K-Ready, E-Shift, XPR, etc., depending on the brand you are working with.
Simply put, pixel shifting uses a WUXGA or 1080p chip and, with advanced processing, shifts each pixel either diagonally or horizontally and vertically at rapid speeds, creating multiple sub-frames that are combined to produce a higher resolution image on screen. The process happens so fast that our eyes are not able to detect the individual frames, resulting in an image that rivals native 4K at a significantly reduced cost. Additionally, it is important to note that there is more than one method of pixel shifting. For this article, I will refer to the terms used by Epson to describe them.
4K Enhancement was introduced first and has now been on the market for several years. Projectors that feature 4K Enhancement can receive 4K (3840×2160) signals and project ultra high definition (UHD) images by shifting each pixel diagonally by 0.5 pixels, effectively doubling the on-screen resolution to approximately 4.15 million pixels. This allows support for a wider range of available input resolutions in a given system and displays image quality higher than HD when showing 4K content.
More recently, a new type of pixel shifting has been introduced, which Epson is calling 4K Crystal Motion. In this case, the pixel shifting happens both horizontally and vertically, effectively quadrupling the resolution of the 1080p chips to show 4K (3840×2160) with 8.3 million pixels on the screen. Here, a very critical eye would be required to discern the difference between this image and one coming from native 4K chipsets, while projectors using this technology are also significantly less expensive than those offering native 4K.
Lastly, there is native 4K, where the projector uses advanced imaging chips with no pixels being shared, providing the utmost accurate presentation of the source signal and resulting in the highest possible quality, but at an additional expense compared to pixel shifting. So which one should you consider? This will depend on a variety of factors, including but not limited to image size, viewing distance, source content, the resolution of the source material, and budget.
With larger image sizes, the potential for a user to see the individual pixels on screen increases; however, this is reduced when viewing distance increases. Additionally, the type of content being displayed matters. Naturally, a PowerPoint presentation would not require the same level of detail as spreadsheets or engineering drawings, and it’s possible the client may not even have 4K resolution content in the first place.
Like any other project, the key to success is understanding the needs and vision of the client and then providing the best solution given their budget. Look closely at specifications to be sure you are getting the right projector for the intended purpose. The bottom line is projectors that use pixel shifting will allow you to display 4K content with an image quality rivaling native 4K projectors at a significantly reduced cost and will meet the needs of many commercial video projects.
Have more questions? Contact Exertis Almo for a consultation.
Check out one of Brian’s other blogs, “5 Keys to Selecting a New Projector“.
