HIGH POWER a Review! Part 1 - Page 116

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I bought it from AudioGeneral. Da Lite said that they have never seen anything like that.

Then they need to send you a new one and get that one back to figure out what they did wrong!

In your opinion, who should pay the cost of shipping from Italy?

Dalite or the vendor. you didn't cause the problem!!

Ok , thanks... I'm waiting for answer from AudioGeneral.

I took a different approach. I built a steel frame, and used magnets to attach the screen. No mess, no glue, easy to adjust for flatness, holds the material very tight

First thing that came to my mind was....

It looks like a return where someone tried some kind of
homemade 2:35 masking that went wrong.

You shouldn't pay anything as far as I'm concerned...if they don't make good let them know you will post about
them refusing to make good. Give them a chance before blasting them on the net.

I have not accused anyone.
I just wanted to see if someone else had huge success.
I've always rolled out the screen completely, and I've never tried a masking system.
Sorry for my English.

So what have they told you they will do? Are they willing to replace the screen?

I was asked (as Blue Rain) if I ever rolled out partially the screen or if I clean.
I said no, but I do not have more than answered.

Well I replaced my 2.8 133" HP with a 2.4 133" HP. My projector is ceiling mounted so it is not ideal. I have had the 2.8 for seven years so I was familiar with the picture.

I was scared that there would be a noticeable loss of brightness. I am happy to report that the 2.4 seems to handle my setup really well and looks amazing with no real noticeable drop in brightness . In fact the picture seems more uniform with ambient light.

It also gives a sightly different picture which I think gives better color. Over all I love it and feel no regret.

Makes sense. The 2.4 theoretically works better of-axis, as your ceiling mount setup is. So you should have as good or even a little better performance.

Sorry..I never accused you..I said it looked like a return meaning someone else not you might have tried some kind of masking for 2:35.

guys after paying 1/2 money advance 2 weeks ago to my dealer he called me today to tell me that my model c 110" has reached him from usa.

I told him i'll go over to his office to inspect the screen before paying the rest of the money and only then will i take the delivery.

1. Can some of the owners share with me what kind of general defects can be there in the screen that i should look out for ? I want to be sure the screen is trouble free before taking delivery and installing it.....

2. So what are the most common things to look out for ?

Thanks

Duplicate post

I am not trying to blame you for the damage to your screen, but I have to ask. Do you ever pull the screen down in a non-vertical manner ie in more of a horizontal direction?

The reason I ask, is because my HP has the exact same problem as yours. Maybe not as noticeable and I only have the dark horizontal line at the top of my screen instead of top and bottom.

I scrutinized the screen when I first installed it and the anomaly definitely was not there.

One time I caught my wife attempting to roll up the screen and it got stock. She then proceeded to "jiggle" the screen up and down to unlock it. However, she was pulling it more towards her instead of straight down.

I never thought much about it at the time, however shortly after I noticed the anomaly on the screen. I just assumed the horizontal pulling somehow damaged the beads on the screen. I remember reading somewhere in the dalite literature that you should always pull the screen straight down.

Edit - sorry I just noticed that you have an electric screen. Needless to say you probably don't have anyone pulling on the screen. Weird because my issue looks so similar to yours when I take a flash photo.

Well I just purchased a 130" wide custom high power screen. Recieved it about a week ago.

Figured I would punch in the numbers in FLboys calculator http://www.avsforum.com/avs-vb/showt...213577&page=19 post #566 and I get this for the screen uniformity.

1.68 1.68 1.68 [very top of screen]
1.82 1.87 1.82 [middle of screen]
2.01 2.12 2.01 [very bottom of screen]
Difference from top and bottom of .33 gain

Im assuming I will notice this sort of hotspotting correct? I cant check as Im still awaitin on my projector to be delievered.

Here were my inputs...

2.4 [gain]
130 [screen width]
38 [room floor to middle of screen]
72 [projector lens to floor]
200 [throw distance]
156 [viewing distance]
0 [projector centered]
39 [viewers eyes to floor]

What do I need to do? Build a riser? Lower projector, closer or farther throw distance? Or maybe this is not all that accurate, but im sure its pretty accurate.

UPDATE: well, then I tried the other "all screen gain calculator". which gives me much better results. Which one is the best and more accurate calculator to use.

1.94 1.93 1.94
2.01 2.02 2.01
2.10 2.13 2.10
Bottom and top difference on by .16 gain

Yes , and i never touch the surface.

If your projector is at 72" off the floor, and your viewers eyes to floor is only 39", you will probably notice the bottom of the screen being brighter than the top, particularly showing solid colour backgrounds.

Either lowering the projector or raising the seats (and screen with it) will help provide more uniform gain. Lowering the projector is obviously the easiest solution if that can be practically done. The closer you can get the projector height to viewers' eye level, the more uniform the gain will be.

Thanks Fat Dave -

I could lower the projector about a foot more and thats it. So to 60". But this only helps by .06 gain [so instead of .33 offset top and bottom, I would get .27].

I just cant seem to get them to be uniform using the calculator. The only way this gets uniform, via the calcualtor at least, is to be directly under the projector. just typing in 60" alone does not show the results of uniform. But I guess nobodys setup is perfect.

I could move my projectors throw a foot closer but I dont like to have the projectors zoom maxed out.

Do you mind me asking your viewing distance and throw range, etc so I can get pluck this into the calculator and get an idea. The high power is such beautiful screen mounted, dont want to have to comprimise.

Um.. you guys may want to read the first couple pages of this post to understand how the HP works .. you will see a uniform image from any location, you will not see hot spots or bright areas at all... You just won't get the gain if you are out of the cone..
If anyone who has a big giant HP can see a non uniform image do to changes in gain when seated at the sides please post that fact, because I have never seen it on my tiny screen and I have never heard anyone post that they have seen a non uniform image, after all the is one of the major benefits of the retroreflective surfaces...

What he said. If you're like the vast majority of HP owners, you will never perceive a uniformity problem. I never have. Can't say the same for my Stewart Firehawk.

Thank you so very much guys. I was looking at the calculator, and I saw what it said for top right, top center, compared to the bottom right and so forth, and it just spooked me as I dont have the projector near screen center [error margin from top and bottom says .33 gain. And I wasnt able to test, as Im still awaiting projector. thanks for the comfort.

FWIW, my pj (RS20) is on a stand just behind and above viewers heads (eyes ~ 36" above floor, pj ~ 45"). Screen (110"x62" 16x9 HP2.8) center is ~ 49" (31 + 18) above floor. Works great, even with over 1300 hrs on the lamp.

I understand perfectly how it works, and use one every day. The image is not "uniform" from any location - this is completely false. It may "appear" uniform, or be "more uniform" than with angular reflective material, but that's about as far as you can take the argument.

The gain varies with the angle between the incident light and the viewer, hence you will achieve different levels of gain at different points on the screen. There is no "hot spot", but it is entirely possible to have higher gain at the bottom of your screen than at the top (or if you or the projector is offset, from side to side). It is also entirely possible that you can see that difference. When my projector was ceiling mounted, it was visible. Put up a solid background using a ceiling-mounted projector with an HP screen and you will see it.

The closer the projector lens to the viewers eyes, the less variation in gain across the screen, and the more uniform the image will appear. The fact that it may not "look" unbalanced even when it is, well that's another matter. Not noticing something is not the same as something not being present.

It's simple optics. There's a reason that the gain calculators floating around don't just spit out one number.


We didn't even discuss being seated at the sides, so I'm not sure who this was meant for.

For others - most of this we discussed yesterday via PM, but I missed the last part in your message.

My setup is as follows:

2.8 gain material
155" wide, 65" high
Projector height about 53"
Distance projector to screen about 213"
Front Row viewers eye level about 40"
Front Row distance viewers to screen about 156"

You can see that even with the projector closer to eye level, the numbers still won't come out uniform. You'll never get it perfectly uniform, unless you have the worlds smallest screen... All you can do is strive to get closer, and it will get to a point where the differences in gain are so minor as to be nearly unnoticeable.

My biggest discrepancies right now come from the fact that the projector is so far behind the front row, so I get a bit of a delta in brightness towards one side of the screen from some seats when I'm using the full screen width.

It's slight, and probably I'm the only one that notices it, but it is there. It's still far less distracting to me than the light fall-off and edge contrast loss I had with my old HCCV screen. I won't be giving up this material any time soon.

I still think optimizing your setup is key to maximizing the value (and enjoyment) of this investment, and I think it's important for potential HP customers to know how best to take advantage of the material.

Don't totally agree with this, FD. The relevant angle (for a retro-reflective screen) is that between two lines going to a point on the screen, one from the pj and the other from your eye. If your eye is close to the pj, then this angle will be close to zero for ALL points on the screen, so that the gain will be essentially the same for all points on the screen.

True. One way to test it is to take a photo of a solid white field. Then use Photoshop or some other image editing software to cut and paste areas of one section of the screen into others. Depending on where you took the picture, you will see the unevenness. Another technique I've used to tell the difference is to take a small white "window" in Photoshop and move it quickly side to side across the screen. I can then see the change in brightness.

However, it is very difficult to pick up on those variances in any sort of normal viewing environment. Even when I'm working in Photoshop with large areas of light color, it's extremely difficult to pick up on the differences, because they're so gradual across the screen. The eye is easily fooled. For normal movies, it's a complete non-issue. OTOH, on my Firehawk the changes in brightness and color across the screen are clearly visible in many movies. There's also a snowy sheen that the HP does not have. I also saw a different sort of sheen while watching the sample of Silverstar screen that Vutec sent me. The HP has no sheen.

While there are numerical differences in brightness as demonstrated by the screen gain calculator, they do not impact my normal viewing in any meaningful way. I can't say the same for other screen materials I've seen, where screen artifacts are clearly visible (and distracting) in very typical viewing situations. If I can't see a problem, it's not a problem. I also like to think I have a fairly critical eye. For instance, while some people say they don't see much in the way of brightness changes outside the cone, I can see brightness changes on the HP as I shift from left to right in my chair. That might sound like a condemnation, but for all practical purposes (for me), it's meaningless.

The best way to know if the HP will be right for a particular individual is to send for samples. That told me all I needed to know. I drown pretty quickly in numbers. I trust my eyes - especially if I put the samples side by side and simply move around in the room.

Yes, you are correct with what you've posted, so I must not have explained myself very clearly.

The quoted reference pertains in particular to my setup, having the projector so far behind the first row. Even though the projector is only 13" above eye level, having the projector so far behind the viewer creates greater angles between the two incident lines towards the sides of the screen versus a placement with the projector closer to the viewing point. Because of this, in my setup there is a greater disparity in the gain from screen center to the screen sides, and there is also a greater disparity in the gain from one side of my screen to another when seated off-centre.

I hope that clears things up a bit.