New High Contrast High Power Discussion Thread - Page 12

Not hard to believe; as per my previous calculations: ith my curtains out 2ft from the wall it boosted the contrast around the edges 22% for a worst-case scenario image (all white, with one small black square). 9% at the center (which is less affected by scattered light).

I imagine the effect would be even higher for HP material, which'll scatter more to begin with.

Using your push-pins, were you able to keep the material pretty tensioned on the ceiling/wall? So as to avoid it drooping? I suppose if it were tensioned & flat on the ceilings/walls, it'd look more acceptable to me. I see I can also get the 0.04" 'FlockBoard', which I assume would be nice & rigid? Tack that to the ceiling? If it's light, I may be able to get away with a few small nails in the ceiling & some neodymium magnets...

millerwill-- did you get the board or just the 'self adhesive hi-tack flocked light trap' material (http://www.fpi-protostar.com/hitack.htm)? If the latter, are tacks (how many?) enough to hold it up? Is it really light? Does it stay relatively straight (unlike velvet cloth, which just droops everywhere)?

Now you've got me pretty interested in this combo of HP with the ProtoStar material. Like I said, if it's just straight/flat on the ceilings/walls, I guess it wouldn't look so bad. Do you have a picture of your home theater setup?

Thank you!

The ProtoStar material is truly remarkable; it is essentially the same kind of black felt that covers the Dalite screen frame.     I use the 'zoom method' for 2.35, and the 'black bars' that are projected above and below the screen when its zoomed out 12 ft wide totally disappear with this material (which I also have on the screen wall that is not covered by the screen itself).

 

Re ProtoStar, I tried the 'flock board' but found its backing too heavy and thick.    So I used the 'self adhesive' material, that you can get 30" wide (IIRC) and of arbitrary length.    But I LEAVE THE PLASTIC BACKING SHEET ON IT, i.e., I don't use the adhesive aspect of it, and attach it to the ceiling and side walls with push pins (using ones with black plastic heads, so they are essentially invisible).   I suppose you could peal off the backing and use the adhesive to hold it in place.    But it is SO STICKY that it would be very hard to work with in large sheets.   This material is light weight enough that it is no problem for it to be held with the push pins (which was not true for the heavier 'flock board').     [I did cover the sides of my speakers that catch reflected light from the screen with ProtoStar, and for these I did peal off the plastic backing and use the adhesive to cover the relevant sides of the speakers.    With these smaller pieces, it was easy enough to work with.    But the adhesive is VERY STICKY, so I think it would be very hard to do this for the ceiling.    Also, since I first tried this out a a test, I didn't want to make an irreversible commitment, and thus used the push pins; and since they worked well, I just went with them.]

Awesome, thanks very much for the input. Yeah I can't use the adhesive sticker because I move a lot. Did you have to use a ton of them to hold it up, & does it still look relatively flat/flush with the ceiling with just the tacks?

My floor is also light colored & reflects a lot of light. Think the material you got will lie flat on the floor (say with a slip-pad)? Or is it going to curl/move around a lot? Thanks.

My room is ~ 14 ft W, so I used the 30" W sheets cut to this length, and used push pins on each side of these sheets about every 3-4 ft.    And yes, it makes the covering quite flush/flat; it absorbs light so completely that any small ripples are totally invisible.    Putting it up on the ceiling is of course the hardest, and it's very useful to have someone help you keep it straight, etc; it's quite easy for the side walls.

 

Re the floor, I don't think this material would work well for it; it really wouldn't take any foot traffic.     I have hardwood floors, but a large darkish oriental rug covering most of it and don't have any reflections from it.     [My room is not a specially constructed 'screening room' type HT, but simply a former master BR, 14x17.5, that I've just taken over for my 'HT'.]

That's great info millerwill-- thanks! Is the material easy to cut (with scissors)?

My 'HT' is in my main living room, since I just have a 2BR condo. Hence why I'm reluctant to put up dark stuff everywhere. But ProtoStar on the ceiling and an oriental rug on the floor are totally doable. There's no left wall but the right wall is extremely close to the screen (1-2ft), so that'll likely be a problem. I feel it'll be ugly coated with the ProtoStar material.

Here's my room (note the remarkable scatter with matte white 1.1 gain material):


Funny, in this case, I feel like a left wall would've been nice... at least then I could've symmetrically coated both walls with the ProtoStar material. Then combined with the ceiling, it would've created a nice 'box' effect.

P.S. With the 110" screen, since it's considerably smaller than the 120" screen pictured above, I moved the entire screen down quite a bit. So there are less ceiling reflections. I also hate looking up at a screen during viewing.

Yep, easy to cut with scissors.    Looks like the absence of a left wall will eliminate much reflection from that side, and that it should be relatively straight-forward to put up ProtoStar on the ceiling and right wall.    Have fun!

Shoot I forgot about the 'Draper Contrast Radiant' screen (http://www.draperinc.com/filedownload.asp?pathname=ProjectionScreens\TechDataSheets&filename=OptiView_Contrast_Radiant_CH2700E.pdf). I got a sample & it was very similar to the HCHP material (despite it having a claimed 2.7 gain & 30º viewing angle); look at the patch labeled 'Draper' below:



Does anyone here have experience with the Draper surface? Perhaps it doesn't have the texture problems of the HCHP?

Seriously, why are there like no threads on the Draper Contrast Radiant screen? I even have a feeling their tensioning method is much better than Da-Lite's. For example, look at the corner of my Cinema Contour Da-Lite screen... I can't get rid of the ripples there, & I can see it in my projected image:



I've tried unsnapping it at various corners & re-tensioning/snapping corners. Nope. The upper left & bottom right both have these ripples. And, yes, I can see them in projected content, if I'm looking for them anyway. Which of course now I am :-P

The Draper system uses a rod that spans the entire length. Seems smarter to me.

The Draper product does look interesting.   You'll just have to find out what you can about it to see if it delivers on what it advertises.

 

I agree that the wrinkles in your Cinema Contour Dalite screen look unacceptable.      (I have the DaSnap frame and have a very even, smooth result.)    You might want to see about getting Dalite to send you a replacement.

Yeah, but rather than fuss with X number of HCHP screen surface replacements, I'm wondering if it wouldn't be more efficient for me to return the entire Cinema Contour HCHP screen ($1200), and just buy the Draper screen ($1000). I don't even know if I can do that without raising a fuss.

Really, the problem is: if Da-Lite released the HCHP screen, we viewers should NOT be beta-testers/QC. Every time I swap out the HCHP surface for another one, I have to:

1. Take down my old screen, & unsnap the screen from the frame
2. Wrap up the old screen material meticulously
3. Unwrap the new screen material meticulously
4. Attach it to the frame, a huge PIA given the tension you have to apply during snapping.
5. Re-mount the entire frame
6. Watch a bunch of content to see if there's texture
7. Ship the old one back
8. Stay home on day of delivery of new screen, and carry it in myself b/c CEVA Logistics is a piece of crap company who won't even deliver the screen any further than they feel like parking their truck.

That should not be my job. I already have a job. Did Da-Lite create QC jobs so I don't have to do this nonsense?

This screen was $1200. Not $0. You'd think I'd be paying for some level of QC.
Edited by sarangiman - 1/3/13 at 11:40pm

As you state, but shouldn't the bend angle and viewing angle be the same in the special case of a retro-reflective screen with the source of illumination directed along the screen normal at the center of the screen? They would really be throwing us all for a loop if the source of illumination was off-axis!

edit: also assuming same behavior for vertical displacement since no vertical gain chart is provided for any of the HP screens (i.e. as is the case for some of the 'optical' screens designed to reject overhead or side-lighting).
Edited by dougri - 1/3/13 at 10:56pm

I understand the hassle!   I have never had a problem with the screen material, but the first HP2.8 I bought came with the wrong frame size (not Dalite's error, but it was written down wrong by the AVS salesman), and the present HP2.4 came without the black material covering the frame (as I had ordered).     Packing up and returning these was a hassle, but I must admit that Dalite dealt with it very well, instantly airfreighting the replacements, etc., and paying for all the extra shipping.

 

I have no info about Draper, but I'll bet you can find out a lot by googling them and reading some, probably here on the Forum.     Another much less expensive gray, retro-reflective screen is Optoma's Graywolf, but in the past I read much about its 'texture' problems; not sure if it has been improved or not.    Again, I would do a lot of reading about it before committing.

I had the Optoma GreyWolf... it's bad enough that I'm spending $1200 to upgrade So, yeah, the texture was terrible. It did a good job of rejecting ambient light/reflections though, while concentrating light to the center.

I just can't find any info about Draper, anywhere. Nothing on AVS either. You can see I started a thread here last night... no responses yet:
http://www.avsforum.com/t/1449462/draper-contrast-radiant-vs-da-lite-high-contrast-high-power-hchp

A close inspection of the Draper vs. the HCHP shows that they appear to be the same exact material... the underlying weave/texture is the same between the two. Gain/color & everything else appears to be the same. So I wonder if it's sourced from the same manufacturer... hence there's reason to believe it might have the same issues as the HCHP.
Edited by sarangiman - 1/11/13 at 11:59am

Didn't you say they would swap out the HCHP for the HP.. I think you will find the HP is a better choice than the HCHP..

I agree with this.

A grey screen is preferable for a room with light-colored walls/reflections b/c scattered light reflected back on the screen is amplified less than a white screen. Not to mention the narrower viewing cone of HCHP scatters less light than HP to begin with.

Thanks, Mark, for pointing me to the following article explaining some of this:
http://www.hometheaterhifi.com/volume_13_2/feature-article-contrast-ratio-5-2006-part-1.html

So fix the walls.. I own the older HP 2.8 and have had the 2.4 (sent it back for the 2.8) and looked at HCHP samples (would never buy it).. you would be happy with the 2.4 and if not, fix the walls and ceiling. You don't have to do much just the first couple of feet.
Having a crappy picture due to the poor quality of finish with the HC will be far worse than any reflection form the walls on the standard HP, but good luck with whatever you end up with.

Since I currently still move around a lot (city condo living), it's hard to fix the walls & ceilings; however, I do intend to give the ProtoStar material a try (thanks millerwill). I tried triple black velvet curtains, which really help, but they're ugly & they still leave contrast to be desired with a white screen.

Regardless, that's not even my point. I didn't know that the grey HP material *has* to have texture. Why should it if the HP doesn't and when non-textured grey screens exist?

One can't argue that a grey screen won't help with contrast, and I'm saying I need all the help I can get with contrast... hence my search for a high gain grey screen (high gain b/c I do enjoy the brightness, especially as a lamp ages, and because the limited viewing cone helps scatter less light compared to light sent to the viewer's eyes). I'm wondering if a non-textured high gain grey screen even exists at this point, either in the form of a better copy of the HCHP or the Draper Contrast Radiant.

I think the problem is the combo of high gain and gray, in a retro-reflective screen.     E.g., I think the Stewart Firehawk, a gray screen with ~1.3 gain, doesn't have texture issues, but it is not retro-reflective and requires a fairly large throw distance to avoid hotspotting.    

That high gain coating appears to be sprayed on the current 2.4 gain HP products, and I think with the gray under it, the manufacturing process shows up. There is no guarantee the HP won't have streaks as is evident by the issues others have had. Some of those were corrected by cleaning other were not. Have you asked Dalite or whomever you purchased the HCHP from if you can try cleaning it to see if the surface imperfections are removed?

I don't have the HCHP, but the regular HP2.4; it is creamy smooth, and essentially 'disappears', even moreso (IMHO) that the original HP2.8, which was also excellent in this regard.

Wait, there have been complaints of the HP having texture/streaking as well?? I don't recall ever seeing complaints of the HP material.

But then again, I wouldn't be surprised, because... I don't see why spraying the microbeads on a white vs. a grey surface would make a difference. If it's uneven bead coating, then that should show up on the white surface as well, unless you argue that the white surface renders such a bright image that your eyes don't really pick it up. But that argument seems specious when you consider the texture is *easiest* to see in very bright scenes on the HCHP material (literally, white scenes). So it doesn't seem to me like brightness helps mask the texture; on the contrary, brightness seems to increase my perception of the texture.

So... if all HP screens are texture-free, I'd expect it was the grey base coat that is uneven in the HCHP material. Really at this point we'd need to talk to an engineer at Da-Lite...

In case anyone's curious, here's an almost microscopic shot I took of the HP surface:


Just for fun The HCHP surface looks similar at these magnifications; I'm guessing it's just the underlying base that's different? Although, that wouldn't explain the faster fall-off in gain of the HCHP material, so maybe there's some difference in the beads/density of coating?

BlackDiamond is out for me b/c the texture/sheen of that material is ridiculous to my eyes.

The FireHawk was reasonable; no texture, but its rather wide viewing cone scattered a lot of light to the ceilings in the Magnolia in Seattle where I checked one out.

I may ask my dealer to swap out the HCHP screen altogether for a Draper Contrast Radiant; but unmounting/shipping these huge screens is a nuisance. I'd really love to read at least one report of someone with the Contrast Radiant... but I can't seem to find any.

Re: cleaning. Interesting. Perhaps I should give that a try!

Here is a picture of the HP 2.8 (sample) and the new 2.4 HP when I discovered Dalite had changed the HP screen material and gain without telling the public or their customer service people back in 2010.
Left picture is old HP 2.8 right is current 2.4. In person you can see the difference in manufacturing better than the photos..

Cool! How did you take those?

If those are the same scale, look like the new material has smaller beads. I didn't notice much size difference between the beads of the HP & HCHP material in my own shots, but I also didn't have quite this level of magnification.

Oh, jeez, there's complaints of texture problems on the HP as well... doesn't seem like it's any better than the HCHP:
http://www.avsforum.com/t/773065/high-power-a-review-part-1/3630

Must be the coating process; probably has nothing to do with the grey base... which makes sense to me, as I mentioned earlier.

So it's a QC problem with all the HP materials? Wonder if Draper fares any better...

From my observations, the HP2.4 doesn't have such issues, as does the HCHP.     But of course I haven't seen more than my own screen.

I have a $99 machinist microscope and rigged a wooden stand with a hunk of foam to put the camera lens on.. it isn't easy with a camera that does not have a manual focus..
Yes the manufacturing process between the old 2.8 and 2.4 was very different. The 2.8 had larger beads, closely packed and probably embedded in the substrate. The 2.4 has different sized beads that appear to be in a white emulsifier. This give the 2.4 mush more white area (there was no white in the 2.8) so the base gain is higher than the 2.8 and off axis is a little brighter. The reason for the switch according to one sales manager at Dalite was to address quality control problems... but if you ask me it was about a cheaper product and obviously they have just as many issues if not more.
Here is the post from 2010
http://www.avsforum.com/t/1213577/da-lite-hi-power-new-or-old-what-did-you-get/0_100

Many manufacturers including Da-lite went to a smaller bead coatings a number of years ago because with the higher resolution (1080P) the pixels distort more when they are smaller than the bead. This might not happen with the HP and a large screen but does with smaller screen sizes.

The HP and HCHP are two different gains. Although, they have the same overall gain the HCHP starts with a gray base. So it is probably about a .85 gain screen with ~3.0 gain coating. That's why it has a smaller viewing cone.

I remember you blowing the whistle on this one back in 2010. I bought one of the last 2.8HP's made. It's also the largest Cinema Contour they've sold. No one knew you could get the 2.8 larger than a 133" without seams. A VP @ Dalite custom ordered the 142" 2.8 CC I have now.

thanks for posting those photos. The 2.8 beads look more consistent in size and placed closer together. The 2.4 beads appear to be various sizes and random placement. I asked a Dalite exec why they stopped making the 2.8. The claim was the materials were costing too much. I've installed a number of 2.4's and like them, but always wishing they still made the 2.8.

I hope nothing ever happens to my screen.... I guard it better than my projectors.....