To Curve OR Not To Curve? - AVS Forum
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post #1 of 8 Old 08-19-2013, 09:20 PM - Thread Starter
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Advantages and disadvantages to curve screens?

I would have to assume a brighter image for the viewer and not as much of a wide angle for viewing.

What about pin cushions on the sides or any other pluses or minus for a curve screen?
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post #2 of 8 Old 08-21-2013, 08:57 AM
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Quote:
Originally Posted by OzzieP View Post

Advantages and disadvantages to curve screens?

I would have to assume a brighter image for the viewer and not as much of a wide angle for viewing.

What about pin cushions on the sides or any other pluses or minus for a curve screen?

Advantages:

Compensates for pincushion distortion caused by a horizontal expansion anamorphic lens

Has a high "coolness" factor

Creates a more immersive experience

Disadvantages:

Creates barrel distortion on 16:9 images when the anamorphic lens is not in place

Slightly reduced viewing cone

Cost

So much of this, though, depends on the specifics of your install. If you have a short throw, a curved screen may be of real benefit. If your projector is mounted further away than 3X the screen height, the need for a curved screen is less. If you can share your specifics it would be really helpful.

Something to keep in mind - you should NEVER pair a curved screen with a vertical compression lens like the Panamorph U85, UV200, or FVX200, as they create barrel rather than pincushion distortion.

The amount of curve you need depends on the throw ratio. Shorter throws require a greater degree of curve.

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post #3 of 8 Old 09-20-2013, 02:51 AM
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Quote:
Originally Posted by John Schuermann View Post


Disadvantages:

Creates barrel distortion on 16:9 images when the anamorphic lens is not in place

Slightly reduced viewing cone

Cost

I was considering the curve screen idea but I am not using a anamorphic lens just projector zoom for 2.35 movies. The screen I am interested in a 103 inch screen with a 40' radial axis curvature which is a subtle curve, flat to the wall in the middle to a 3 inch wall to frame separation at the ends.

I was thinking that the curve would help with contrast and color depth loss in the image that seems to happen when zooming by both bringing the side edges slight closer and reducing side wall (ambient light) .

With only a slight curve do you think barrel distortion on 16:9 images would still be a problem?
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post #4 of 8 Old 09-20-2013, 03:17 AM
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1 other dis-advantage

-focusing audio onto 1 spot region - if the screen is solid like my DW screen is, those with AT screen a non-issue

Yea I found this by doing test tones and sitting in 1st row and being totally surprised at certain location small spot zone the audio was focused coming from my back wall, reflected off the curved surface, to a location.
If I moved side-side or forward-backward the focused sound was not there as strong, just a small zone.
I might do some plot with my db meter next time I'm tweaking.

Just like a magnifying glass does with light, sound acts same above the transition freq range, say 300hz and higher, that's why we can use ray-tracing in simulation and mirrors in real world acoustic analysis.
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post #5 of 8 Old 09-21-2013, 11:36 AM
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Quote:
Originally Posted by Socio View Post

I was considering the curve screen idea but I am not using a anamorphic lens just projector zoom for 2.35 movies. The screen I am interested in a 103 inch screen with a 40' radial axis curvature which is a subtle curve, flat to the wall in the middle to a 3 inch wall to frame separation at the ends.

I was thinking that the curve would help with contrast and color depth loss in the image that seems to happen when zooming by both bringing the side edges slight closer and reducing side wall (ambient light) .

With only a slight curve do you think barrel distortion on 16:9 images would still be a problem?

A curved screen really won't do anything positive if you're not using an anamorphic lens.

See what an anamorphoscopic lens can do, see movies the way they were meant to be seen
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post #6 of 8 Old 09-21-2013, 12:33 PM
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I will slide my A lens away, put a grid pattern onto my curved screen - zoom it ti 2.35:1, and post it.
Do same, but with a-lens for compare.

Ha - in my memory I did that 3-4 years ago somewhere in this CIH forum, but can't find that post/thread just easily.

Here is a image of my screen 5 years ago in build phase, when I posted the focus grid thru my a-lens onto the screen frame to confirm it's size was correct to real world before I applied the DW laminate to it.
IMG_0145.JPG


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post #7 of 8 Old 10-23-2013, 11:20 AM
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Similarly, if the throw distance is longer, the barrel distortion when screening an AR without the anamorphic lens would be minimized, right?....and then you would keep some of the cool factor...especially if the sides are masked.
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post #8 of 8 Old 12-02-2013, 10:19 AM
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I'm about to buy a Vutec screen and I'm on the fence whether or not to get their curved, 3D-P model.

It will be 100" diagonal 2.35:1 AR using an anamorphic lens.

Like the original poster, I am interested in knowing what the consensus is among this group about screen curvature in home cinemas. Masking would be nice but I don't think I can afford it. Throw distance will be pretty close, probably 15' or 16'. Speakers will be flanking on on the bottom edge at center. The room has angled walls (roofline). I do want the best 2.35:1 experience possible, and I'm already making 16:9 compromises by having bars on the left and right, which don't bother me at all. I'm not sure I've seen the barrel distortion talked about here so I don't know what to look for with regard to that. I wouldn't want to render HDTV viewing unwatchable for the sake of only slightly better widescreen viewing.

Thoughts?

I'm going to buy a screen in the next few weeks. Apparently the screen I wasn't isn't exactly everywhere for Black Friday/Cyber Monday. LOL.

PS: While I'm at it, how far away form the projector do you guys put your anamorphic lens? In my last theater, I never could get the same sharp focus in 2.35 mode that I got in passthrough mode but my lens was so close to the projector lens that they actually touched slightly. I'm wondering if that was the problem and I should have allowed an inch or so between them.
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