Everyone supports HDR10, so this is the primary HDR standard that most people are talking about today. It is the same one used on BluRay UHD discs, and is found in uses elsewhere.
For broadcast, and I believe most streaming, a second “software” based HDR called HLG, or Hybrid Log Gamma, is utilized. It is a more recent standard, so that a lot of products still do not support it. So far, the Netflix movies etc. that I have watched have lacked HDR, but I expect to see a shift over the next couple of years – likely sooner than later. With projectors, at least, it’s only been about a year since anyone has supported HLG. I assume Netflix, Prime and others will want a decent installed base of “TVs” that have HLG support before they will switch to working with HDR content.
The third method is DolbyVision, which is hardware based. You will find that in X-Boxes, but few (I think) consumer TVs at this time.
But, back to the Home Cinema 4010 and Pro Cinema 4050. Overall, the updated Auto Bright setting (which was available for the older 4000/4040 as a firmware update), definitely improves overall picture quality. Epson seems to continue to work to get HDR right, and thanks to that work, overall, these projectors do not exhibit that "dim" tendency that the original 5040UB/6040UB exhibited as well as the early 4000/4040s.
The Epson Home Cinema 4010/Pro Cinema 4050 supports and claims to achieve the DCI/P3 color standard, thanks to a Cinema filter that slides into place when you demand the best possible color. While lamp based DLP competitors can barely get to REC709 (the older color standard, and a lot don’t even make it to that!) P3 offers a 50% larger color range, delivering color quality comparable to what the better digital projectors at your local theater complex deliver! True, there are some trade-offs: for instance, the Cinema filter drops the projector’s brightness by about 40%. From that perspective, you get to choose either more brightness, or better, P3 color.
At least you get a choice, unlike the competition. By the way, if you go with a really good laser DLP UHD projector, you can find P3 or close, but those typically run $3K to $6K and most we've tested still come up very short on some colors, even if they should be able to get to P3. Per Eric, who has now calibrated something like 10 4K UHD DLPs, including 3 lasers, not even the laser projectors are close to P3. That said, there's nothing inherently preventing a company from building a 4K UHD laser projector and achieving, or getting extremely close to P3, but we just haven't seen one yet. My guess is that some of the very expensive 4K UHD projectors such as those from Digital Projection, may already be doing P3 or close, its just that we never seem to be able to bring any of those in for review.