This could be a very basic question: should I consider center of screen or center of projector lense as a reference point when I calculate off center angle for HP screen? I have a situation when I use optical shift in horizontal direction so the center of screen is few ft on the left from the center of the projector lense. In such case is it still better being closer to the projector or it is better being close to the line going to the geometrical center of the screen?
Better to be close to the projector. The retro-reflective character of the HP sends the most light right back where it came from, i.e., the projector, for each point on the screen.
I've been reading the AVS Forums for many years without posting. I can't begin to tell all the regulars here how much I've learned from your educated posts. The reason I'm posting for the first time is that I just had a "chat" on the Da-Lite website about HCHP, and wanted to share this with everyone. I'm surprised to have only seen one mention and no discussion on this forum about Da-Lite discontinuing HCHP. I asked Da-Lite if this was true, and they responded yes. I asked why, and they said it was due to lack of customer demand. I asked if they had cleared up the early quality problems with HCHP on later production in case I could find an already-built screen for sale at a dealer, and they responded yes, that later production HCHP was much improved. WhiIe I don't know if all of that is accurate, I thought it might be useful to mention in this thread.
I guess that leaves Draper's Contrast Radiant as the only option for anyone who wants an affordable grey retroreflective screen option. I haven't actually spoken with anyone at Draper, but the Contrast Radiant is still listed as an option on their website. From all the comments I've read here, a grey retroflective screen is the best option for my situation, so I guess I'll be dealing with Draper and will post my experience in the main Contrast Radiant thread.
I had read plenty about the HCHP's issues and never heard that they had addressed so assumed they hadn't.
Nor was I aware of the Draper Contrast Radiant, which sounds like the gray HP that many of us had wished for.
A bit curious how it has essentially identical claimed gain and half-gain viewing angle but is gray vs. white.
I've read comments right here on the Screens forum that Da-Lite cleaned up the early problems on both the HP 2.4 and HCHP 2.4, and those who bought screens after the first few months did not report problems like the early ones.
Draper's Contrast Radiant has also been mentioned in a few threads here on the Screens forum: Draper Contrast Radiant vs. Da-Lite High Contrast High Power (HCHP), Anyone have experience w/ the Vutec Silverstar or Draper Contrast Radiant?, and a couple of others.
Consensus among the few who've compared samples or actual screens seemed to be that the Draper Radiant was very similar to HP 2.4 and the Contrast Radiant very similar to HCHP despite different specs from the two companies, and they were possibly from the same supplier and could be virtually identical.
The HCHP/Contrast Radiant discussion here seems to have gone silent, which fits in with Da-Lite telling me they dropped HCHP due to lack of demand. It's interesting that the discussion here went from the concept of a grey retroflective screen being a "holy grail" for ambient light rejection to apparent indifference about the availability of one. Hopefully Draper will continue selling the Contrast Radiant to keep alive the option for people like me who really need the qualities it offers.