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Q I tried to watch Cruella on Disney+ and was shocked by the poor video quality presented by my Roku streaming device. I have noticed other dark looking movies in the past, but this example was just terrible. I was able to make Cruella watchable by changing the color mode and lamp settings on my Epson HC 4010 projector, but still wonder exactly what happened. Have you noticed that some movies look notably darker than others? If so, does it have anything to do with high dynamic range (HDR)? —Gary Eickmeier, via email

A What does it have to do with HDR? Everything, most likely, though Disney+ isn’t necessarily at fault in this case, and neither is your Roku device. Cruella on Disney+ is in Dolby Vision, a dynamic HDR format where the image is optimized on a frame-by-frame basis for best presentation. All projectors, including your Epson, however, only support HDR10, a static HDR format where the display is provided with both the peak brightness of the video content and its maximum average frame light level and then adjusts the “tone-mapping” to adapt for that. (All movies mastered in Dolby Vision also include an HDR10 layer for compatibility with non-Dolby Vision displays.)

For movies with relatively low HDR brightness (and Cruella, presumably, is one such title), the consequent tone-mapping can result in an image that looks overly dark, especially in dim scenes. But viewed on a Dolby Vision-capable display — a category that only includes flat-panel OLED and LCD TVs at this point — the same image might appear noticeably brighter. Some projectors such as JVC’s higher-end models improve on the HDR10 situation by providing frame-by-frame adaptive tone mapping. In this case, the dynamic range for each scene or frame is optimized on-the-fly regardless of the brightness level of the specific content.

Your Epson Home Cinema 4010 projector is an older model that does support HDR10, though it doesn’t provide any additional settings to optimize HDR image quality. But one feature, a 16-step HDR10 adjustment Epson introduced in later models such as the HC 5050UB and HC 3800, does help quite a bit to improve the look of overly dark or bright 4K/HDR movies. This feature, which can be accessed by hitting a dedicated button on the remote control, displays an onscreen slider that allows you to easily tweak the projector’s tone mapping balance while simultaneously viewing the effect of your adjustments on the image in the background. The result might not pack the same visual punch as a Dolby Vision movie on a flat-panel TV, but it should appear noticeably less dark.

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