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Discussion Starter #1
I am in the process of building a theater. I do not want to pick out my projector ahead of completing the build. I also do not want wire for multiple outlets in my ceiling. My screen will be a 10ft wide 2.35 screen. I intend to use an anamorphic lens setup. What would be ideal throw distance to set my projector at so I can prewire. I am thinking about 15.5 - 16 ft from the screen. Optionally, I can place the projector in a soffit on the back wall, but that distance would be approximately 17 - 18 feet, which seem too far to me based on what I have read. I am looking for the ideal distance that would fit most projectors for a 2.35 theater. Thanks for the help.
 

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Quote:
Originally Posted by tally999 /forum/post/13016648


I am in the process of building a theater. I do not want to pick out my projector ahead of completing the build. I also do not want wire for multiple outlets in my ceiling. My screen will be a 10ft wide 2.35 screen. I intend to use an anamorphic lens setup. What would be ideal throw distance to set my projector at so I can prewire. I am thinking about 15.5 - 16 ft from the screen. Optionally, I can place the projector in a soffit on the back wall, but that distance would be approximately 17 - 18 feet, which seem too far to me based on what I have read. I am looking for the ideal distance that would fit most projectors for a 2.35 theater. Thanks for the help.

Read: http://www.panamorph.com/FAQ.html

and also http://www.panamorph.com/SetupBasics.html

Quote:
Panamorph User Guide - Setup Basics


Basic Requirements

Throw ratio example based on a 2.35:1 screen width of 100" and a throw distance of 180" ...

If you use the U85 lens then your pre-lens 16:9 width must be the same as the 2.35:1 screen width since you are creating 2.35:1 by only changing the image height. Consequently, the throw ratio of your installed projector would be 180"/100" = 1.8.


If you use the UH380 lens your pre-lens 16:9 width will be 0.75 times the 2.35:1 screen width since you will be horizontally expanding the 16:9 image to achieve 2.35:1. Therefore the throw ratio of your installed projector would be 180"/75" = 2.4


Throw ratio (or sometimes "native" throw ratio) is defined as the distance (or "throw distance") between your projector lens and screen, divided by the width (in the same units) of your projector's image before the addition of a Panamorph lens. Anamorphic lenses always perform best with higher throw ratios. Residual aberrations, especially edge distortion, can become unreasonable at throw ratios below about 1.65. Residual edge distortion at higher throw ratios is minor enough to become masked off even with a thin screen border. At 2.0 and above distortion becomes very difficult to see. To determine a projector's range of throw ratios most accurately, use the manufacturer's stated maximum and minimum image width for a typical throw distance.


A small throw ratio means that the beam entering the lens is expanding quickly and could be cut off by the size of the lens. The model U85 lens will accept a beam size of up to 1.5" high x 2.25" wide. However, model UH380 will accept a beam up to 3.1" wide at throw ratios down to 1.6. Smaller beams may also be used with the UH380 down to throw ratios of approximately 1.4. However, you may wish to use a curved screen to compensate for edge distortion with these very small throw ratios. You can find out your beam size by putting a piece of paper in your beam where the Panamorph lens would be positioned. Use a bright scene that uses the full pixel array of the projector and then zoom to the largest image size for the most challenging case. Note that a longer throw ratio can decrease the beam size. Consequently, even larger projectors may work fine at longer throw ratios.


Panamorph patented lenses are optimized to substantially correct for astigmatism for a throw distance of between about 12 to 26 feet. A throw distance beyond this range will begin to show the slight softening of partial astigmatism at the pixel level.


In general, The U85 lens is ideal for creating 2.35:1 images at longer throw distances because projector beams are typically smaller in these cases. The U85 lens takes advantage of Vertical Compression (VC) optical technology for a simple, high performance design at relatively low cost. Consequently the final 2.35:1 image will have the same width as the 16:9 image before the lens is used. Alternatively, the UH380 lens is suitable for a broader range of throw distances due to its larger apertures. Since the UH380 uses Horizontal Expansion (HE) optical technology, the final 2.35:1 image is 33% wider than the 16:9 image before the lens is used.


Proper use of Panamorph lenses requires electronic scaling either by the projector itself, an external scaler, or by input devices such as DVD players or HDTV receivers that may have the proper scaling modes. Check with your projector or scaler manufacturer for compatibility. Virtually all major projector manufacturers are familiar with Panamorph lenses and the requirements for their use. Note that projectors and other devices may offer scaling modes that achieve the correct result but may use different terminology to describe them.


Scaling Mode I: 2.35:1 movies are displayed by the projector vertically stretched by 33%. This mode is the minimum necessary mode for all Panamorph-enhanced projectors regardless of whether the lens is moveable or permanently positioned.

Scaling Mode II: Content is horizontally squeezed by 25%. This mode is only necessary if the lens is permanently positioned in front of the projector lens. It is not needed if the lens is moved away from the beam for non-2.35:1 content.


Installation Tips

Panamorph, Inc. assumes no liability and makes no warranties regarding the suitability of mounting suggestions. If you are uncomfortable with mounting your Panamorph lens please consult with a qualified home theater installer instead.



Pan-2 U85/M85 lens mount by

Chief Manufacturing


Note: For best performance, do not use

horizontal lens shift when using

anamorphic lenses.

Panamorph lenses (and their transport options) come with their own mounting bracket. Instead of mounting directly to a ceiling, the simplest approach for the U85 lens (or the M85 transport) is to use a projector ceiling mount by Chief Manufacturing with a Panamorph mount adapter. The next simplest approach is to use a sheet of rigid material as a common plate. Make a first set of holes in the plate that match the ceiling-mount holes on the projector while allowing enough plate area to extend beyond the front of the projector for mounting the fixed or moveable Panamorph lens model. Now position the lens appropriately and make holes for mounting the lens or transport bracket using screws, nuts and other common hardware that makes sense. Note that even with the mounting plate you may need to make some type of vertical extension block if the projector lens is far below the plate. Now make any appropriate openings in the plate to allow for projector intakes, vents or connection ports that would otherwise be covered by the plate. Finally, trim the perimeter of the plate to a shape that makes it look nice but retains its strength. To install, insert the ceiling mount screws through the appropriate holes in the ceiling mount, through the matching holes in the plate, and finally into the threaded projector mounting holes. Caution One - you may need to replace the screws that came with your ceiling mount with longer screws to make up for the added thickness of your plate. Caution Two - the UH380 lens is so heavy that you should connect some sort of cable or chain system from the front of the assembly to the ceiling to prevent the assembly from tilting forward. Now install the Panamorph lens. It is really not that difficult of a project. But when assembled and installed this arrangement typically results in a very professional configuration that you can be proud of and looks very "meant-to-be". Just make sure you use common sense in the choice of material and how you assemble and mount for sufficient strength and safety.
 

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Discussion Starter #3
Thanks for the response. I realize the answer to my question is not a simple one. So, if use the U85 lens: 1 take the 120" wide screen x 1.8 to get the distance, which would be 216 inches or 18feet. Do most anamorphic lenses work at this length with a 120" screen (1.8). The 18ft throw distance seems real long to me. Many projectors that I run through the projector calculator at projection central (at 16:9) do not seem to have enough lumens at this distance?


The screen I will use will only have a gain of 1.16. I am going with Shearweave fabic making a DIY AT screen.


What am I missing here? Thanks again.
 

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Quote:
Originally Posted by tally999 /forum/post/13017006


Thanks for the response. I realize the answer to my question is not a simple one. So, if use the U85 lens: 1 take the 120" wide screen x 1.8 to get the distance, which would be 216 inches or 18feet. Do most anamorphic lenses work at this length with a 120" screen (1.8). The 18ft throw distance seems real long to me. Many projectors that I run through the projector calculator at projection central (at 16:9) do not seem to have enough lumens at this distance?


The screen I will use will only have a gain of 1.16. I am going with Shearweave fabic making a DIY AT screen.


What am I missing here? Thanks again.

When I built my HT room, even 2 months ago, I was not 100% sure projector, 16:9 or 2.35:1 (which I'm going now), screen, etc.


I "package protected" by just putting in a few extra 2 x 12"s as shown, gives me wiggle room both for distance to screen and some side - side also.


Now, I'm actually going to mount my 2 week old Sony VPL-VW60 there (I'm also getting in on the UH380 b-stock deal) and do some real world viewing before I decide on how wide the 2.35:1 screen will be, 120" diag or 128" diag or tbd, honestly I don't know, but having the flexibility is nice and easy before drywall went up.

Before drywall



after drywall:
 

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Discussion Starter #5

Quote:
Originally Posted by mtbdudex /forum/post/13017825


I "package protected" by just putting in a few extra 2 x 12"s as shown, gives me wiggle room both for distance to screen and some side - side also.

About how far away are you from your screen at your center point (your middle 2x12)?
 

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I would work it this way...figure if you had to pick 1 throw ratio that covered the most amount of projector options...it would be around 2x screen width. Now, you have to figure out your 16:9 equivalent width (based on your height), and multiply that by 2x. So in your example, 10' wide 2.35:1 = 51" tall x 91" wide 16:9. 91" x2 = 182"...that would be ballpark where I would put it if you really had to guess on it.
 

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Quote:
Originally Posted by Jason Turk /forum/post/13031130


I would work it this way...figure if you had to pick 1 throw ratio that covered the most amount of projector options...it would be around 2x screen width. Now, you have to figure out your 16:9 equivalent width (based on your height), and multiply that by 2x. So in your example, 10' wide 2.35:1 = 51" tall x 91" wide 16:9. 91" x2 = 182"...that would be ballpark where I would put it if you really had to guess on it.

I'm new to this forum but was also wanting to prewire. I think I'm going to buy the Panasonic AE-2000U. I used a projector people calculator to determine throw distance and was wondering how much the zoom comes into play. I figured the quality went down, but didn't know if there was an average or standard used. I think the room is 18-20 feet long. Does height really matter that much? Aren't projectors always mounted about a foot or two from the ceiling?
 

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I wouldn't worry about the zoom too much. The affects of it on the image are minor at best. But, you should know that at the longer end of the throw, the higher the contrast. And the shorter end of the throw the higher the light output.
 
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