No more than 1".
Vern
Vern
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Masks - How far from screen?
How much space is acceptable from the surface of the screen to the masking before parallax starts to become noticeable on side seating?
The front row will be 3 chairs wide, about 11 feet from a 110" screen.
For the moving masks, are we talking 1/4", 1/2", 1", 2+" from the screen?
I need to have an idea of how compact I need to make the moving bits.
-Suntan
The front row will be 3 chairs wide, about 11 feet from a 110" screen.
For the moving masks, are we talking 1/4", 1/2", 1", 2+" from the screen?
I need to have an idea of how compact I need to make the moving bits.
-Suntan
1 - 18 of 18 Posts
I agree with Vern, 1.0 ins max, but the closer the better.
Based on the geometry I would assume that, if a person had to pick one, having the top/bottom masks further from the screen surface than the side masks would be better?
Or is it the other way around because the top/bottom masks cover more if the image edge?
-Suntan
Or is it the other way around because the top/bottom masks cover more if the image edge?
-Suntan
On my 110 ins wide 2.35 screen, my bottom mask is fixed directly to the wall, so I get a razor sharp edge along the bottom of the picture. The top mask rolls down within 1 ins of the wall, and the side masks are about 2 ins from the wall. The side masks would be better if they were closer in to the wall, about 1.O ins would be fine, but with a 3-way masking system this is about as close as I can get it. Still looks great though.
I lower the top mask for the many films which are greater than 2.35, such as the early 2.65 CinemaScope films, and the UltraPanavison films, as well as the odball ratio films like How The West Was Won which is at 2.90.
I lower the top mask for the many films which are greater than 2.35, such as the early 2.65 CinemaScope films, and the UltraPanavison films, as well as the odball ratio films like How The West Was Won which is at 2.90.
Here's an oddball question, what about on a curved screen? Anyone tried using a strait masking system (ala the Masquerade CIH) on a curved screen?
I'm curious because a curved screen (to go with a nice lens) is somewhere in my master plan, but there's now way I'm buying a curved masking system (heck, I'd be DIY-ing the screen even)....
I'm curious because a curved screen (to go with a nice lens) is somewhere in my master plan, but there's now way I'm buying a curved masking system (heck, I'd be DIY-ing the screen even)....
If you have something like the Stewart Vistascope this is exactly how the panels work. The top and bottom height are fixed with the sides moving beween them and the screen material.
Art
Quote:
Originally Posted by Suntan /forum/post/16845333
Based on the geometry I would assume that, if a person had to pick one, having the top/bottom masks further from the screen surface than the side masks would be better?
Or is it the other way around because the top/bottom masks cover more if the image edge?
-Suntan
If you have something like the Stewart Vistascope this is exactly how the panels work. The top and bottom height are fixed with the sides moving beween them and the screen material.
Art
Close as possible, but try and avoid it touching. Screen fabrics are fragile and having a masking system (especially DIY if that is what you are doing), you should pay added attention to making sure you don't hurt anything.
Well, with a 2 yr old boy and another one on the way, I am planning to go with the Wilsonart DIY screen for the next few years. After the Mrs. denied the proposal to put electrified fencing around the stage perimeter
That said, I was considering keeping the bits from touching the screen, to eliminate the chance of dust or other residue from streaking and needing to be cleaned off continually.
-Suntan
Quote:
Originally Posted by Jason Turk /forum/post/16852909
Close as possible, but try and avoid it touching. Screen fabrics are fragile and having a masking system (especially DIY if that is what you are doing), you should pay added attention to making sure you don't hurt anything.
Well, with a 2 yr old boy and another one on the way, I am planning to go with the Wilsonart DIY screen for the next few years. After the Mrs. denied the proposal to put electrified fencing around the stage perimeter
That said, I was considering keeping the bits from touching the screen, to eliminate the chance of dust or other residue from streaking and needing to be cleaned off continually.
-Suntan
So is this more for protection than aspect ratio changes? Sorry I am not clear...
For DIY masking, using a wall screen, the best way to go is to fix the top and bottom masking directly to the wall and have the side panels slide on the outside. This minimizes the gap between the masking and the wall since you only have one gap to contend with. If you do what Art eluded to (side panels on the inside), then you have two gaps to contend with and the top and bottom masking is going to be much further out from the wall.
Getting masking close enough to the screen has been an issue for me since I'm combining
2 systems to get 4 way masking. (I haven't put the system up...should happen within the next couple of weeks).
If one is doing 4 way masking, at least one set of masks, top/bottom or sides/ are going to be further away than the other, for obvious reasons (one set of masks have to clear the other). I'd guess that having the top/bottom masking as close as possible would be best since those masks span the whole image in front of you, whereas the side masks may move more into peripheral vision (depending on the size screen/viewing distance).
When I examined a Stewart 4 way masking system a while back I was surprised at the distance of the masks from the screen (a larger gap than I expected). But I don't remember noting any shadowing.
In my case the Carada Masquerade is doing top/bottom masking, which means I should be able to get those masks around 1/4" from the screen. Based on the distance I need to clear those masks, my side masks should be able to get to within 3/4" or mostly likely 1" from the screen surface. Hopefully that will work out ok.
2 systems to get 4 way masking. (I haven't put the system up...should happen within the next couple of weeks).
If one is doing 4 way masking, at least one set of masks, top/bottom or sides/ are going to be further away than the other, for obvious reasons (one set of masks have to clear the other). I'd guess that having the top/bottom masking as close as possible would be best since those masks span the whole image in front of you, whereas the side masks may move more into peripheral vision (depending on the size screen/viewing distance).
When I examined a Stewart 4 way masking system a while back I was surprised at the distance of the masks from the screen (a larger gap than I expected). But I don't remember noting any shadowing.
In my case the Carada Masquerade is doing top/bottom masking, which means I should be able to get those masks around 1/4" from the screen. Based on the distance I need to clear those masks, my side masks should be able to get to within 3/4" or mostly likely 1" from the screen surface. Hopefully that will work out ok.
No. I plan to use the Wilsonart surface material partly due to cost and partly due to the ability to clean it in case little ones with their messy fingers get up on stage (which will be an inevitability at some point in the coming years.)
I plan to do masking because I want masking. I am looking to make it automated because I am lazy. I am debating how much complexity I want to add into it (just 16/9 and 1:2.35 or 16/9, 1:2.35 & 4:3) also because I am lazy and how I do it will be dependent on what will minimize effort, both in the design as well as in the usage. If that makes any sense.
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The other thread about a different topic, but directly related to this investigation, can be found here:
http://www.avsforum.com/avs-vb/showthread.php?t=1163098
-Suntan
Quote:
Originally Posted by Jason Turk /forum/post/16855050
So is this more for protection than aspect ratio changes? Sorry I am not clear...
No. I plan to use the Wilsonart surface material partly due to cost and partly due to the ability to clean it in case little ones with their messy fingers get up on stage (which will be an inevitability at some point in the coming years.)
I plan to do masking because I want masking. I am looking to make it automated because I am lazy. I am debating how much complexity I want to add into it (just 16/9 and 1:2.35 or 16/9, 1:2.35 & 4:3) also because I am lazy and how I do it will be dependent on what will minimize effort, both in the design as well as in the usage. If that makes any sense.
The other thread about a different topic, but directly related to this investigation, can be found here:
http://www.avsforum.com/avs-vb/showthread.php?t=1163098
-Suntan
I originally thought the same. However, the geometry of the setup says that if the side masks are further away from the screen, a person sitting in the far left seat would be able to notice the shadow that the right mask casts on the screen due to parallax, and vice versa for the person on the far right seat.
Now if the projector is mounted on the ceiling (higher than the viewer’s heads) then it doesn’t matter how far away the bottom mask is from the screen, the viewers will not see the shadow. They will see any shadows cast by the top mask though, but unless your screen is really freaking tall and you have seating right up front laying on the ground, it wouldn’t be as noticeable because the angle from the “lowest head” compared to the height of the PJ will be much less, relatively speaking, than the situation above where the sides are spaced away from the screen. Clear as mud?
Now the $64 question is, is it more noticeable to see larger shadows on the smaller masks that are all the way to the two sides of the screen, or see smaller shadows on the larger masks right at the top and bottom of the screen? My guess would be that the sides aren’t as important for scope material, but for 16x9 the side masks aren’t really “out of your field of vision.”
In any case, I am just mulling around a couple of different ideas while priming what seems like 65 miles worth of trim pieces in the basement. I haven’t gotten serious about designing the masking system yet.
-Suntan
Quote:
Originally Posted by R Harkness /forum/post/16856670
I'd guess that having the top/bottom masking as close as possible would be best since those masks span the whole image in front of you, whereas the side masks may move more into peripheral vision (depending on the size screen/viewing distance).
I originally thought the same. However, the geometry of the setup says that if the side masks are further away from the screen, a person sitting in the far left seat would be able to notice the shadow that the right mask casts on the screen due to parallax, and vice versa for the person on the far right seat.
Now if the projector is mounted on the ceiling (higher than the viewer’s heads) then it doesn’t matter how far away the bottom mask is from the screen, the viewers will not see the shadow. They will see any shadows cast by the top mask though, but unless your screen is really freaking tall and you have seating right up front laying on the ground, it wouldn’t be as noticeable because the angle from the “lowest head” compared to the height of the PJ will be much less, relatively speaking, than the situation above where the sides are spaced away from the screen. Clear as mud?
Now the $64 question is, is it more noticeable to see larger shadows on the smaller masks that are all the way to the two sides of the screen, or see smaller shadows on the larger masks right at the top and bottom of the screen? My guess would be that the sides aren’t as important for scope material, but for 16x9 the side masks aren’t really “out of your field of vision.”
In any case, I am just mulling around a couple of different ideas while priming what seems like 65 miles worth of trim pieces in the basement. I haven’t gotten serious about designing the masking system yet.
-Suntan
I have 4 way masking and the sides are closest to the screen with the top/bottom masking panels a bit further away to make room for the side panels. It works out well and I do agree that it is ideal to have the side masks closer than the top/bottom masks.
Wow, this has opened up a whole new topic that I have never really given that much thought to. Great points from one and all!
One thing I have found, is that the shadowing from the side masks becomes more noticeable as you go wider in aspect ratio, which makes perfect geometric sense, since the angle of the projector beam is that much larger for 2.35.
To eliminate this problem, I have added FIXED vertical masking for the left and right 2.35 wall screen, so essentially I have a fixed 2.35 screen with fixed 2.35 masking all the way around. The moveable side masking rides in front of this on a track, but it is set up so that for the 2.35 position it actually goes slightly wider than necessary and the fixed side masks of the 2.35 wall frame come into play. This totally eliminates all shadowing (top, bottom, and sides) in the 2.35 position.
One thing I have found, is that the shadowing from the side masks becomes more noticeable as you go wider in aspect ratio, which makes perfect geometric sense, since the angle of the projector beam is that much larger for 2.35.
To eliminate this problem, I have added FIXED vertical masking for the left and right 2.35 wall screen, so essentially I have a fixed 2.35 screen with fixed 2.35 masking all the way around. The moveable side masking rides in front of this on a track, but it is set up so that for the 2.35 position it actually goes slightly wider than necessary and the fixed side masks of the 2.35 wall frame come into play. This totally eliminates all shadowing (top, bottom, and sides) in the 2.35 position.
Hmmm...I hope my system works out.
I plan to bevel the side masks to get the edge closer to the screen surface. The beveled side masks will always reside within the sides of the screen frame (not outside) so the beveled edge never needs to clear the screen frame.
Still, that gets me 3/4" to 1" to the screen material at best.
I plan to bevel the side masks to get the edge closer to the screen surface. The beveled side masks will always reside within the sides of the screen frame (not outside) so the beveled edge never needs to clear the screen frame.
Still, that gets me 3/4" to 1" to the screen material at best.
As long as you aren't too close to the screen that should be fine.
Quote:
Originally Posted by R Harkness /forum/post/16859125
Hmmm...I hope my system works out.
I plan to bevel the side masks to get the edge closer to the screen surface. The beveled side masks will always reside within the sides of the screen frame (not outside) so the beveled edge never needs to clear the screen frame.
Still, that gets me 3/4" to 1" to the screen material at best.
As long as you aren't too close to the screen that should be fine.
1 - 18 of 18 Posts
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