[Stump909]

I know the general consensus is that ambient light viewing should utilize a grey screen to help darken the blacks, but with a higher contrast projector (such as the Panny AE-7000u) could decent blacks be achieved in an semi-ambient light condition?

 

[mechman]

Define your version of ambient light? Is it hitting the screen?

Maybe. :T

 

[Stump909]

Well the room is currently under construction, with some steps being taken to minimize direct light exposure. On the wall, left of the screen, is a stairwell with a glass door. The door has the potential to allow light, so a curtain will be placed on the outside. The wall to the right will have 4 ft of actual wall, until it turns into a 12ft long series of windows. The outside will be wooded and covered by a porch, so direct sun exposure should be non-existent. Ambient light on the other hand will be allowed in, but not directly infront of the screen. If needed, a curtain can be installed, but that could be pricey due to the size. The ceiling will have 9 recessed can lights in a 3x3 array and a flush ceiling fan in the center (to allow a ceiling mounted projector behind it at around 12.5'). I'm specifically asking the electrician to put the front 3 cans (nearest the screen) on a separate switch. The wall color has yet to be selected, but I believe I can make it a dark blue or tan without angering anyone (I may even be able to make the screen wall a shade or two darker). The carpet will most likely end up being a tan color.

Here are my hopes for the room:
The screen will be 2.35:1. I plan on installing light-absorbing curtains over the screen for 16:9 content. I've made the promise, which I'm unsure I can keep, that 16:9 content (sports, television) can be viewed during the day with the right-wall windows uncovered and the back six lights possibly on. The general consensus is that we don't want the room to feel like a cave for general television viewing. This is where the screen color comes into play. The projector we're looking at (ae-7000u) has a fairly high contrast ratio. The benefit of that would be most appreciated on a white screen, but if my setup will create a washed-out image during general viewing, I'm willing to settle for grey. Have I taken enough precautions to use a white screen? Btw, screen size will likely be 100"-115" 2.35:1.

 

[tonyvdb]

Just remember that the blackest blacks will only be as black as the darkest part of the screen so any light hitting the screen will affect the black levels (Black is the absence of any light) its not like the projector is "projecting" the black onto the screen

 

[Stump909]

Also, off-topic but sort of relevant to my setup. How quickly do powered-lens projectors switch zoom levels for different aspect ratios. My favorite showcase movie is Tron Legacy. It's part IMAX 1.78 and part 2.35. If I'm watching the film, will the projector be able to make adjustments on the fly or will I have to watch the entire movie in 16:9 not to experience any overly zoomed-in scenes?

 

[mechman]

If you can keep light from getting back to the screen or at least keep it at a minimum, a white screen will be fine for you. It sounds like your color choices for the walls will help. And keeping the lights closest to the screen on a separate switch will help as well. But given you projector choice and approximate mounting location, a gray screen would work well for you as well. With a 110" screen and a .9 gain gray screen, you'd have around 18fL at the screen.

So now the question is, why not gray? :bigsmile:

 

[tonyvdb]

It takes about 5 to 7 seconds for the Panasonic to zoom and focus the lens during the aspect ratio change and during that time it displays "Processing" on the screen so its a bit annoying.

 

[Todd Anderson]

If you can keep light from getting back to the screen or at least keep it at a minimum, a white screen will be fine for you. It sounds like your color choices for the walls will help. And keeping the lights closest to the screen on a separate switch will help as well. But given you projector choice and approximate mounting location, a gray screen would work well for you as well. With a 110" screen and a .9 gain gray screen, you'd have around 18fL at the screen.

So now the question is, why not gray? :bigsmile:

Mechman is obviously the more expert "expert" on these issues... Just to add, I have a light controlled HT with ultra flat black walls/ceiling on the front half of the room and very dark brown flat on the back... With some track lighting w/dimmers on the back half of the ceiling. I have a Carada cine-white 1.0 gain screen. In this set up, I've noticed little to no black degradation if the lights are left on dim.

 

[salesguy]

Well the room is currently under construction, with some steps being taken to minimize direct light exposure. On the wall, left of the screen, is a stairwell with a glass door. The door has the potential to allow light, so a curtain will be placed on the outside. The wall to the right will have 4 ft of actual wall, until it turns into a 12ft long series of windows. The outside will be wooded and covered by a porch, so direct sun exposure should be non-existent. Ambient light on the other hand will be allowed in, but not directly infront of the screen. If needed, a curtain can be installed, but that could be pricey due to the size. The ceiling will have 9 recessed can lights in a 3x3 array and a flush ceiling fan in the center (to allow a ceiling mounted projector behind it at around 12.5'). I'm specifically asking the electrician to put the front 3 cans (nearest the screen) on a separate switch. The wall color has yet to be selected, but I believe I can make it a dark blue or tan without angering anyone (I may even be able to make the screen wall a shade or two darker). The carpet will most likely end up being a tan color.

Here are my hopes for the room:
The screen will be 2.35:1. I plan on installing light-absorbing curtains over the screen for 16:9 content. I've made the promise, which I'm unsure I can keep, that 16:9 content (sports, television) can be viewed during the day with the right-wall windows uncovered and the back six lights possibly on. The general consensus is that we don't want the room to feel like a cave for general television viewing. This is where the screen color comes into play. The projector we're looking at (ae-7000u) has a fairly high contrast ratio. The benefit of that would be most appreciated on a white screen, but if my setup will create a washed-out image during general viewing, I'm willing to settle for grey. Have I taken enough precautions to use a white screen? Btw, screen size will likely be 100"-115" 2.35:1.

Could you post what you decide to do? I am in the same situation with the screen. I have an Epson which is very bright, and I have low watt recessed lights with no direct light shining towards where my screen will be placed. I am also finding it hard to find an inexpensive ceiling or wall mount gray screen. i can not do a fixed screen on my wall. Good luck

 

[Stump909]

If you can keep light from getting back to the screen or at least keep it at a minimum, a white screen will be fine for you. It sounds like your color choices for the walls will help. And keeping the lights closest to the screen on a separate switch will help as well. But given you projector choice and approximate mounting location, a gray screen would work well for you as well. With a 110" screen and a .9 gain gray screen, you'd have around 18fL at the screen.

So now the question is, why not gray? :bigsmile:

Well, as I said, I'm not totally against gray. It just seems the general consensus is that a gray screen will cause a high contrast projector to lose it's vibrancy in the dark. Color is relative though, and a proper calibration should minimize the problems. Right now I'm actually leaning towards the Elite Cinegray. Your measurements in another thread show that it has a nice neutral grey at around N8. Hopefully that should provide a nice picture with the lights on, as well as a brilliant display with the lights off.

 

[Stump909]

It takes about 5 to 7 seconds for the Panasonic to zoom and focus the lens during the aspect ratio change and during that time it displays "Processing" on the screen so its a bit annoying.

That's unfortunate. How does 1.78 framed material look when over zoomed onto 2.35? This is assuming you can disable the autocorrection for moments like this.

 

[Stump909]

Mechman is obviously the more expert "expert" on these issues... Just to add, I have a light controlled HT with ultra flat black walls/ceiling on the front half of the room and very dark brown flat on the back... With some track lighting w/dimmers on the back half of the ceiling. I have a Carada cine-white 1.0 gain screen. In this set up, I've noticed little to no black degradation if the lights are left on dim.

You seem to have the setup I wish I could have, but compromises must be made . Its good to hear dimmed lights work for you, but I'd have a really hard time convincing the household that dimming the lights wasn't "cave" like.

 

[Stump909]

Could you post what you decide to do? I am in the same situation with the screen. I have an Epson which is very bright, and I have low watt recessed lights with no direct light shining towards where my screen will be placed. I am also finding it hard to find an inexpensive ceiling or wall mount gray screen. i can not do a fixed screen on my wall. Good luck

Right now I'm leaning towards the Elite Cinegray 235, but if anything changes I'll be sure to post. I know that feeling though. I'm lucky enough where a fixed frame works for my setup. I couldn't image having to drop an additional thousand just to make the screen retractable. Have you tried looking in the used market? I've seen decent options on craigslist occasionally.

 

[tonyvdb]

That's unfortunate. How does 1.78 framed material look when over zoomed onto 2.35? This is assuming you can disable the autocorrection for moments like this.

yes it can be disables and manually with the remote made to fit how ever you like. 1.78 looks fine as long as its not a poor quality image.

 

[Todd Anderson]

You seem to have the setup I wish I could have, but compromises must be made . Its good to hear dimmed lights work for you, but I'd have a really hard time convincing the household that dimming the lights wasn't "cave" like.

I hear ya, bro. We all have those compromises. Good luck with your choice. Hope it all works out!

 

[mechman]

Well, as I said, I'm not totally against gray. It just seems the general consensus is that a gray screen will cause a high contrast projector to lose it's vibrancy in the dark. Color is relative though, and a proper calibration should minimize the problems. Right now I'm actually leaning towards the Elite Cinegray. Your measurements in another thread show that it has a nice neutral grey at around N8. Hopefully that should provide a nice picture with the lights on, as well as a brilliant display with the lights off.

Hogwash. As long as the gray is neutral it is no different to color than a white screen. Your pj has more than enough lumens for a gray screen.

What I would suggest is to get samples of the gray and white materials you are leaning towards and putting them up and seeing how they compare in your environment. I know the room is under construction but if you have the pj, call the companies and ask for a large sample - 18" square or larger. The number of companies that don't send samples are very few these days.

 

[Stump909]

Well just an update. I'm 90% certain I'm sticking with the cinegray. I'm running into one issue though:

According to Mech's 2008 gain readings, the viewing cone for the cinegray looks quite poor.

These reading are a lot worse than what Elite provides: http://www.elitescreens.com/images/pdf/MaterialSheets/cinegrey_materialsheet_w.pdf

How exactly does a projection screen view angle work? Are those degrees from the center of the screen or from the edge of the screen? If a screen is 10ft long and the couch in front of it is 10ft as well, wouldn't everyone sitting still be squared with the screen?

Is it possible the material has changed since 08 and that's why the readings are so drastically different?

Thanks

 

[Harpmaker]

Well just an update. I'm 90% certain I'm sticking with the cinegray. I'm running into one issue though:

According to Mech's 2008 gain readings, the viewing cone for the cinegray looks quite poor.

These reading are a lot worse than what Elite provides: http://www.elitescreens.com/images/pdf/MaterialSheets/cinegrey_materialsheet_w.pdf

Is it possible the material has changed since 08 and that's why the readings are so drastically different

My guess is that the CineGrey attributes did change from the time Mech did his testing or there is something wonky with Elite's chart.

In Mech's chart gain was measured at 0, 5, 10, 15, 20, 30, 35 and 45 degrees (you can "connect the dots" on the chart at these data points) with Excel interpolating the areas between data points.

The chart from Elite seems to have been measured at 0, 10, 15, 25, 30, 40 and 45 degrees. According to this data this screen would be considerably lighter in color and less glossy than Mech's CineGrey.

How exactly does a projection screen view angle work? Are those degrees from the center of the screen or from the edge of the screen? If a screen is 10ft long and the couch in front of it is 10ft as well, wouldn't everyone sitting still be squared with the screen?

Thanks

0 degrees is the viewers position when they are on-axis horizontally with the projector (setting in the middle of the couch if the PJ is horizontally centered with the screen).

Assuming the couch is 10 feet from the screen, the person setting on-axis in the middle of the couch would be viewing the center of the screen head-on at 0°, but would be viewing the edge at 26.5° (if my trig is correct). The people setting at the ends of the couch would view the screen edge closest to them at 0°, the center of the screen at 26.5° and the opposite edge of the screen at 45° (again if my math is correct, which I won't guarantee). These various viewing angles from a single viewing position is what makes hot spotting of a screen such an issue. To make the whole deal even more complicated all the light rays from the projector aren't striking the screen at the same angle, but are also in a cone and off-center vertically. Da-Lite issued a White Paper on this, but I forget the details at the moment :doh:; it was very interesting reading.

 

[Stump909]

Well thanks for the input. I can only hope the difference in data is caused by a change in the material. It would be unfortunate to find out the brightness drops to 60% on the edges (especially since the screen is 2.35). If it becomes an issue, I might have to move the couch further back...

 

[mechman]

I'm not sure how Elite gets their numbers. :huh: But they did want me to train one of their people on how to do this properly recently. Due to conflicts with my schedule and them no longer being a HTS sponsor, I declined. I do know that a lot of the folks at Elite USA were scratching their heads at the numbers given to them from the Taiwan office at one point in time.