HIGH POWER a Review! Part 1 - Page 117

No disagreement! In your case the 'relevant angle' does indeed vary significantly for different points on the screen. I was just wanting to make the point that IF the eyes were fairly close to the pj lens, then this variation would not exist for any point on the screen. But we all live with the practical limitations of our own configurations. Still, as JC says, even if there is some variation over the screen, it is often so gradual that it is not noticeable in practical viewing.

I actually agree with this. I can see it's not an equal gain across the entire screen. It does an amazing job of perceiving to be equal, but it most defintely is not. Now the further you sit back, the smaller the scree, the closer your sitting to the sweet spot, the less noticeable it will be. I can see it just by putting up a black screen, or and solid color really and move around. It's not a Hot spot, even though by definition it might seem like it. I have had screens that hot spot, it isn't the same.

I'm using a 2.4 gain.

If you have to "move around" to see it, it's not a uniformity issue. What you are observing is different gain from different positions. Uniformity differences are visible from a single position; your viewing position.

I got a silly question. If you can only see this if your projector is not placed within the confides of a proper setup, and you have to put up a solid color or black screen to see it, why talk about it as if it is something to consider when trying to decide if you want to buy the screen? There are enough issues to deal with when it comes to buying a screen, why add something that is a non issue to the mix?.. sorry that is 2 of the same question!

Just to reprint tryg's conclusion of the 2.8 gain from the beginning of this thread (not exactly the same as the current 2.4 but close enough to still hold true)

Conclusions

I’ve been reviewing screens now for a number of years. Every professional screen I look at is very good; and I’m a big fan of companies that have the technology to develop surfaces with optical coatings and that take it to the next level of reflective performance. I personally tend to like higher gain screens and the brightness advantages you can get from them. Of all the screens I’ve reviewed, there’s one screen material that has become my reference standard. That screen material is Da-Lite’s High Power. If set up properly, this material can deliver the best images available. If you are able to set up your viewing situation properly you can expect to see an image that:

Gives a robust high brightness image with real to life colors and whites
Provides greater perceived contrast
Has a clean uniform image so that the surface completely disappears
Has no hotspotting or visable waves
Has an amazing ability to shed ambient light

PLEASE NOTE: The original review that started this thread was of the 2.8 gain fabric that has been discontinued. However the current 2.4 is of the same technology and exhibits the same properties but is slightly different in how it is manufactured.

The question lies in defining "proper setup", and that's rather ambiguous. Ideally with the HP, we all know that it should be placed as close to the viewers eyes as possible, but at what distance does it slip from "proper" to "improper"? There's no hard and fast rule, but rather just a gradual decline in gain and uniformity, and it's up to the individual if the results are within their requirements or not.

Ceiling-mounted setups are quite common, and there are many posts in this thread with users asking about what sort difference they'll see with a ceiling mount versus a mount closer to eye level with the HP.

Commonly, the answer is "less gain", but in reality that's only part of the answer.

Also, this effect is not something you can "only" see with a solid colour. It's just very easy to see it that way, as with testing any screen for uniformity. It's always visible, just not always distracting. The more it can be mitigated with careful placement, the more subtle the effect will be, and the more it will become a non-issue.

But by default, it's another of the variables one should consider when deciding on their individual "proper setup".

I have no idea why anyone would want an HP for off axis viewing with a high ceiling mount. Wrong tool for the job.. but to each his own!

I think the key is that slight uniformity issues could potentially be noticed when you have
a) An extremely wide screen (Is it safe to say that your 155" wide HP screen is wider than most?)
b) A long throw in relation to your seating distance


For other more common setups, most people are unable to perceive uniformity issues. For example, I have a much "smaller" 104" wide screen, but I actually have a much longer throw:seating distance ratio. I still don't perceive any uniformity issues from any angle.

bump...

Da-Lite will ship only a new roller and fabric , whitout cost to me.

Once you get that new roller and fabric, but before you replace it, try cleaning the screen with denatured alcohol and a clean soft cloth. Fold the cloth to fit in your hand poor some on and wipe gently. Do this in the dark with the projector displaying a blank white screen. I had the same kind of line with my 2.8 when I opened it fully and after cleaning the entire screen with alcohol it is like new. Good luck with your project and installing the new roller!

Ok, thanks for the advice.
But I believe that the area is ruined for the rub.
On the back, near the lines, there is a white powder.
However I will try to clean it , until now I've never touched.

I would wait till you have the new one in hand!
2.4 is much different in the way the micro beads are applied to the surface, it looks to be painted on rather than impeded in the backing. It would not surprise me to hear of adhesion problems that would cause this type of issue.

Clean the 2.4 will be more difficult, the surface is rougher than the 2.8.
I'll try to clean it only when i get the new roll.

Before getting HP screen, I am trying to decide color of the paint. I read in the forums that black would be best for ceiling and screen side wall. However, I also read that for Dalite HP screen, the back wall is important.

Is it true? If so, is black paint the best color for back wall?

I am choosing Loyal blue and Tricorn black from Sherwin williams.

The colorist who helped me with my house told me paints have a light absorption index. Some blacks reflect more light than some burgundies, for example. See if you can find that rating for the colors you are interested in. I used a very dark deep blue on the ceiling and back wall with burgundy walls. It turns out the colors don't really matter in my case, because you never really see them, even with lights full on.

Yes, the back wall is very imp for the HP. My wife made some dark burgundy drapes for the back wall that work great. When I pull them to the side, revealing white sliding doors to a closet, the pic degrades enormously.

I never knew there is light absorption index. I will ask Sherwin williams tomorrow. Where are colorists available?

My contractor referred me to the colorist. He did the whole house. I'll see if I can scare up the paints used in the theater and let you know.

I used Sherwin-Williams 7082 "Stunning Shade" (Maroon) and 6054 "Canyon Clay" (Raw Umber, Maroon, Deep Gold)

very good info erkq, i need to look into this as well!

Benito

I enjoyed reading many pages of this thread. I liked all the feedback and no wonder why this thread has so many pages. Dalite support is also excellent patiently answering all my questions.

I have JVC RS40 projector and about to order 142 inch diagonal HP screen today. My wife complained that the light from the projector lense is falling on her eyes whenever she stands and she does not like that. She is not sure how harmful these rays are. She wanted to put the projector wherever possible without needing her to be careful whenever she stands.

I really wanted to try this screen. I told her that we can click hide button on the projector to prevent rays. She did not like the idea.

If I have to place projector higher and if screen behaves like standard screen, I don't have problem. I want to have an option at least to watch 2.4 if needed.

Appreciate any feedback on the placement. I can't wait to order to enjoy phase 2 of the my projector to use screen instead of wall.

The only harm that can be caused it if she can not see where she is walking and runs into something or tips over something. This issue can be solved just like you do when the sun is shining in your eye, put your hand up in front of your face!
If you end up raising the projector you screen will work and probably still be better than the wall. One option is to get the screen and let the wife see how it looks, explain it won't be anywhere as good if we move the projector, so can you find it in your heart to please live with the slight inconvenience of raising you hand to block the light when you stand up and face the projector?
Good luck and enjoy!

What you said is right. I went to Sherwin Williams and found that each color has LRV value (Light Reflective value)

I found that Naval blue (SW 6244) has lowest LRV value 4 out of all blue colors. So for the best color for less reflection is Tricorn black SW 6258 with LRV 2.

I read in the forums that screen wall and ceiling are more important. I thought to put black on ceiling and sceen wall and put dark blue for three sides.

There is conflicting consensus that HP needs back wall to not to reflect. I do not know how it looks to have black everywhere except side walls. I will go for blue on all walls and black for ceiling for consistency.

I would have not known if there is index like LRV without reading this post. Again thanks.

I can certainly verify that minimizing reflection off the BACK wall is crucial for success with the HP screen. I have dark burgundy drapes (that my wife made) which pull across the back wall (covering up a wide closet with white doors). When the drapes are pulled back to expose the doors, the pq drops dramatically.

I also have black cloth (light wt cotton) tacked to the ceiling and side walls, and this also improves things greatly.

Do you have any photos that you can share? I am thinking to go for naval blue on the walls and black on the ceiling. I prefer to put blue everywhere and then cover with black cloth where ever needed.

I heard that sound also good with more cloth. Where did you buy the black cotton cloth? I just read meaning of "tacked". I guess you put small nail.

I'm not much of a photographer, but I think you get the idea. Yes, I think the cloth does do good for audio. I used black push pins; the reason was that I initially told my wife that I wanted to 'try it out', but she soon got used to it and did appreciate the increased pq. And the push pins worked so well that I've not be motivated to re-do it.

The black material was extremely inexpensive light-weight cotton; my wife picked it up for me. I have since bought some more expensive black velour that I plan to put up this summer; not sure that it will improve things even more, for the present 'temporary' job does so well.

I will look in Joann fabric for black cloth next time. I guess it is difficult to put the cloth on the ceiling. I will at least put in the back.

Yes, I started with the back wall, and it is the most imp for an HP screen. After that, it is the ceiling; for that, put the push pins into the left and right sides of the ceiling (into a wooden picture molding), pulling it as tight as possible, and then needed one or two in between to get rid of any sagging.

Thanks for the idea. I am first planning to put nav blue on all sides. I will consider using cloth for next phase starting with back wall.

Yeah I second this, complaing of a light in her eyes is a bit silly. I wouldn't be long setting her straight on this silliness.