Just bought used Panamorph UH380, looking for setup tips and advice - AVS Forum
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post #1 of 31 Old 02-06-2013, 11:43 AM - Thread Starter
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Hello,

I just acquired a used Panamorph UH380, and was wondering it there's anything special I need to know in setting it up. Panamorph no longer has instructions for the 380 on their website, just the UH480. I read through that, and is everything pretty much the same? There don't seem to be any adjustment knobs on it other than the two positional knobs on the side holding it to the bracket, so is it as simple as putting it in front of the projector lens, centering it to the light beam, and angling it so that the pincushion is equal from top/bottom side/side? No focusing or other correction? Also, is it better to put it as close to the projector lens as possible? (I have a pretty short throw).

I currently have a 120" 16x9 screen, and am very excited to get into a CIH setup. There are soooo many 2.35:1 movies, but of course you guys already know that. Thanks!
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post #2 of 31 Old 02-06-2013, 01:12 PM
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Instructions for the UH480 should be the same as the UH380. When aligning the image on the screen, it will help to project a grid pattern. (Your projector will probably have one in its built-in test patterns. If not, most calibration DVDs or Blu-rays will have something similar.) Measure from each side to the center to make sure that the distance is equal on both sides, then do the same from the top and bottom. Also measure the size of each square in the grid at various locations on the screen to make sure they are all as close to equal as you can get.

Oh, don't forget to measure the full width and full height, then divide and make sure that you're actually getting a 2.35:1 aspect ratio. (Technically, a 16:9 projected image with a 1.33x stretch should give you 2.37:1, but a little bit of fudging here shouldn't be noticeable.)

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post #3 of 31 Old 02-06-2013, 04:32 PM - Thread Starter
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Thanks for the info! I'm drawing up plans for a DIY sled mount right now, and have one question at the moment.... does it matter which way the lens is flipped? Longer point to either side of projector lens? What about if I have some horizontal lens shift going on (center of lens is about 10" off center of screen, throw is 13 ft).... is flipping the lens one way or the other beneficial?
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post #4 of 31 Old 02-06-2013, 05:41 PM
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Quote:
Originally Posted by DL4567 View Post

Thanks for the info! I'm drawing up plans for a DIY sled mount right now, and have one question at the moment.... does it matter which way the lens is flipped? Longer point to either side of projector lens? What about if I have some horizontal lens shift going on (center of lens is about 10" off center of screen, throw is 13 ft).... is flipping the lens one way or the other beneficial?

The UH480 and UH380 are identical in setup and configuration, so just follow the instructions for the 480. I strongly recommend taking 10 minutes out of your life to watch the installation video available on this page:

http://www.panamorph.com/8-support/videos

Horizontal lens shift is a pretty big no-no with any anamorphic lens. Can you move the projector so that it is centered side to side? Vertical lens shift (up and down) is ok. If you don't correct for the horizontal lens shift you will end up with a trapeziodal image, with one side of the image being taller than the other.

It does not matter which way the lens is flipped. Again, watch the video and all will make sense smile.gif

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post #5 of 31 Old 02-07-2013, 09:03 AM - Thread Starter
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Thank you for the video link, it's very helpful. I missed that when looking around the Panamorph website. I'll post how I make out after setting it up.
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post #6 of 31 Old 02-07-2013, 09:59 PM - Thread Starter
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Alright, Ive put up some temporary poster boards on either side of my 16x9 screen to test the lens. I'm in the middle of building the ceiling sled mount, but I really wanted to do a quick test of the lens before finishing that, so I steadied my arm on a ladder and held the UH380 in front of my projector. First off, I'm pretty impressed with the optics. It looks really sharp. There is a slight decrease in brightness, but I'm assuming that's from making the same amount of light fill a 33% larger area. Really not a big difference though, it still looks good. There is also a very slight green tint, but again, hardly noticeable and nothing that can't be adjusted with tint controls.

Given my very short throw of 12 ft 9 in, and a throw ratio of what I understand to be about 1.5, the pincushion really isn't too bad. About 1" along the top and bottom. I plan to overshoot onto the velvet border of my future 2.35 screen, so the pincushion doesn't bother me. What did surprise me, however, was that the picture overshot on the sides by quit a bit. About 3 inches on each side. Why would this be happening? The top and bottom lined up rather well, so I don't think a projector lens zoom adjusted is necessary. Is the side overspill because of the very short throw ratio? Or is it because my projector lens is 9 1/2" off center from the screen? You say horizontal shift is a big no-no, and that it would cause one side of the image to be taller than the other. Based on my quick test I could get the left and right heights pretty equal, but would the horizontal shift cause over-stretching as well? My poster board and screen height is laid out in exactly 2.35 ratio, and my math says 2.4 would add 3 inches total, but this is a lot more. I also tried a few movies and a test pattern, and they all did the same thing.

Thanks for putting up with all my questions.
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post #7 of 31 Old 02-08-2013, 10:25 AM
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Good questions.

First off, yes, the decrease in brightness you see is only because you are now creating a 33% larger image. The lens itself hardly impacts brightness at all.

RE: the image overshooting your makeshift screen. Anamorphic lenses like the Panamorph UH480 and DC1 (plus those from other manufacturers) create an image 33% wider than 16:9. Since 16:9 can also be expressed as 1.78:1, we can do some simple math to come up with the aspect ratio that the UH480 creates:

1.78 x 1.33 = 2.37:1

As you can see, anamorphic lenses actually create a 2.37:1 ratio in most cases. Another factor is throw ratio. The shorter the throw ratio, the wider the aspect ratio, so in your case you are probably getting an aspect ratio of around 2.39:1. This is ok, as actually most movies since the mid-70s have been created in the 2.39:1 (commonly referred to as 2.40:1) aspect ratio. If you check the cases of most of your Blu-rays you will find that they say 2.40:1. For this reason, Panamorph has almost always recommended a 2.40:1 screen.

For best image fit you may wish to zoom the picture out into the border of the screen very slightly so that the top and bottom of your 16:9 image is slightly cropped (ie, falling on to the top and bottom area of your screen surround). This also eliminates black bars from most 1.85:1 movies.

You may be concerned that this method will cause you to lose some information at the top and bottom of 16:9 sources (sports, standard HDTV). While this is true, it is also true that such picture information falls into what is called the “picture safe area,” as most 16:9 programs are created with the idea that some top and bottom picture information will be lost to broadcast or display overscan (for example, many flat panel TVs routinely overscan, or crop, about 5% of picture information top and bottom).

I've attached a single page pdf that visually illustrates what I am talking about. QuickGuide-Ratio.pdf 180k .pdf file
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post #8 of 31 Old 02-08-2013, 09:51 PM
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Quote:
Originally Posted by John Schuermann View Post

The shorter the throw ratio, the wider the aspect ratio, so in your case you are probably getting an aspect ratio of around 2.39:1. This is ok, as actually most movies since the mid-70s have been created in the 2.39:1 (commonly referred to as 2.40:1) aspect ratio. If you check the cases of most of your Blu-rays you will find that they say 2.40:1. For this reason, Panamorph has almost always recommended a 2.40:1 screen.

I don't entirely agree with that recommendation, and have chosen to go with a 2.35:1 screen. For one thing, although the photographic and theatrical projection standard for scope cinematography is 2.40:1, there is no standardization in how those movies will be transferred to home video. Some will appear on disc as the full 2.40:1, but many others may be slightly cropped (or open matte, if digital or Super 35) to 2.35:1. There's no consistency in what you'll get, even within the same studio. It depends on the calibration of the specific telecine machine used for the film-to-video transfer. The tech specs on the Blu-ray case are written by the studio's marketing department and have almost no relation to what you'll actually see when you watch the movie.

Also, the scaling algorithms in projectors, video processors and some Blu-ray players are all designed to vertically stretch a 16:9 image so that it will expand to 2.35:1 with an anamorphic lens, not 2.40:1. If you project that image onto a 2.40:1 screen, the picture geometry will be slightly compressed. This probably won't be enough to be noticeable, but it's there. (Ironically, this isn't an issue for zoomers, just for lens users.)

I'm not saying that a 2.40:1 screen is the wrong thing to do. But it will come down more to personal preference than to a legitimate technical reason to pick that ratio screen over 2.35:1.

The difference between the two is so small that this is hardly even worth obsessing over.

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post #9 of 31 Old 02-08-2013, 09:55 PM
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Quote:
Originally Posted by John Schuermann View Post

Horizontal lens shift is a pretty big no-no with any anamorphic lens. Can you move the projector so that it is centered side to side? Vertical lens shift (up and down) is ok. If you don't correct for the horizontal lens shift you will end up with a trapeziodal image, with one side of the image being taller than the other.

John, are you referring to the lens shift where projectors will slide the lens inside the chassis, or to physically turning the whole projector so that it projects at a slightly different angle? I can see how the latter will cause a trapezoidal image, but why the former?

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post #10 of 31 Old 02-08-2013, 11:07 PM - Thread Starter
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Well, I've bought the bullet and ordered a 2.35 screen. Monoprice had the exact size I wanted to maintain the same height as my current 16:9 screen. So I'm pretty much "locked in" to that aspect ratio now.

I see the point of those that say a lot of movies are actually 2.37 or 2.4, but 2.35 is the most popular number that we all know, it's the name of this section of the forum, and it's sold by tons of screen companies, whereas you don't see many off-the-shelf 2.4 screens.

My main reason for asking is that I was just alarmed that (based on my quick hand-held test) the lens is expanding my 16:9 image to what I approximate to be about 2.45:1, in my case about 3" of overshoot on each side with the top and bottom lined up. I was just wondering if this is due to my really short throw ratio of 1.5.
The overshoot on the sides is not the end of the world however, since I'm running my movies through an HTPC, which gives me great flexibility in scaling the image. I can just squeeze it a bit horizontally to make it fit the 2.35 screen exactly, which should look correctly proportioned.

As for horizontal shift, my projector is square/plum/level/perpendicular to the screen, just as the manufacturer recommends. The lens shift dial is turned to accommodate my projector being 9 1/2" off center from the screen. Naturally, the middle-line of the room was a space between ceiling joists rather than a nice joist to screw into, so I had to go a bit to the side with my projector mount.
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DL,

My understanding is that the horizontal expansion of the lens increases as the throw ratio decreases. I learned that the hard way as well, and I have some "overshoot" on the sides as well. Thus, I'm very thankful for velvet!. smile.gif

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post #12 of 31 Old 02-09-2013, 10:22 PM
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I think Panamorph used to recommend a minimum of 1.7x for that lens. Thats the advantage of cylindrical, keeping geometry and focus at the extremes of throw.
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post #13 of 31 Old 02-10-2013, 02:36 AM
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Here my DIY alum plate sled as reference , I have same lens the UH380
http://www.avsforum.com/t/1101036/diy-alum-plate-anamorphic-lens-slide



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post #14 of 31 Old 02-10-2013, 04:44 PM - Thread Starter
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Quote:
Originally Posted by blastermaster View Post

DL,
My understanding is that the horizontal expansion of the lens increases as the throw ratio decreases. I learned that the hard way as well, and I have some "overshoot" on the sides as well. Thus, I'm very thankful for velvet!. smile.gif

Good to hear someone else has had the same experience. I just wanted to be sure it wasn't from the horizontal lens shift. While I *could* center the projector, it would be a lot of trouble and I'd be miffed if it didn't make a difference.


Quote:
Originally Posted by coolrda View Post

I think Panamorph used to recommend a minimum of 1.7x for that lens. Thats the advantage of cylindrical, keeping geometry and focus at the extremes of throw.

Oh no, don't tell me that! smile.gif What's funny is that I was trying to decide between this UH380 and an ISCO 2 that was listed. I almost posted on here asking which would be the better choice, but didn't want to draw attention to the listings since they were on ebay. All my research and reading led me to believe that the ISCO 2 was probably too small for my short throw ratio. From what I've briefly seen so far, I'm very happy with the image quality through the UH380, and I can solve the side overshoot with scaling the video signal. Just hoping I didn't make the wrong choice...


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Here my DIY alum plate sled as reference , I have same lens the UH380
http://www.avsforum.com/t/1101036/diy-alum-plate-anamorphic-lens-slide

Thanks for that mtbdudex! I was looking through many pictures on this forum over the last couple weeks and found yours in particular the most helpful. I got my sled mounted to the ceiling yesterday, but have to get some longer threaded rods since it's too high for the projector at the moment. The lens is so heavy, and is right above my seat. It better never fall!
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post #15 of 31 Old 02-11-2013, 08:52 AM
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There is an old sticky in the Dedicated Theater Design & Construction forum that might give you different ideas also, many ways to accomplish the end result.
http://www.avsforum.com/t/978623/show-me-your-mount
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post #16 of 31 Old 02-11-2013, 10:59 AM
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Quote:
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I don't entirely agree with that recommendation, and have chosen to go with a 2.35:1 screen. For one thing, although the photographic and theatrical projection standard for scope cinematography is 2.40:1, there is no standardization in how those movies will be transferred to home video. Some will appear on disc as the full 2.40:1, but many others may be slightly cropped (or open matte, if digital or Super 35) to 2.35:1. There's no consistency in what you'll get, even within the same studio. It depends on the calibration of the specific telecine machine used for the film-to-video transfer. The tech specs on the Blu-ray case are written by the studio's marketing department and have almost no relation to what you'll actually see when you watch the movie.

Also, the scaling algorithms in projectors, video processors and some Blu-ray players are all designed to vertically stretch a 16:9 image so that it will expand to 2.35:1 with an anamorphic lens, not 2.40:1. If you project that image onto a 2.40:1 screen, the picture geometry will be slightly compressed. This probably won't be enough to be noticeable, but it's there. (Ironically, this isn't an issue for zoomers, just for lens users.)

I'm not saying that a 2.40:1 screen is the wrong thing to do. But it will come down more to personal preference than to a legitimate technical reason to pick that ratio screen over 2.35:1.

The difference between the two is so small that this is hardly even worth obsessing over.

First of all, Josh, I entirely agree with your last statement smile.gif

You are also correct that there is no hard and fast "rule" as to how these films are transferred to video, as I have come across supposed "2.40:1" or "2.35:1" films transferred at all kinds of aspect ratios (1920x810, x 817, x 820, etc). We like a 2.40:1 screen since it is the same as the DCI format, and closest to the "official" aspect ratio decided on by Hollywood since the mid-70s. We also like it because the slight letterbox bars on 1.85:1 movies ends up getting absorbed into the black screen surround in this configuration as well. We certainly don't think someone who orders a 2.35:1 screen is "wrong" by any stretch of the imagination. In fact, most of our screen aspect ratio recommendations are based on the throw ratio of the particular setup. Setups with very long throw ratios end up with narrower aspect ratios and setups with very short throw ratios end up with wider aspect ratios. DL4567 has a pretty short throw, which would explain why he has quite a bit of overspill left and right. We would probably recommend a 2.37:1 or 2.40:1 screen for his particular setup.

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post #17 of 31 Old 02-11-2013, 11:02 AM
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Quote:
Originally Posted by Josh Z View Post

John, are you referring to the lens shift where projectors will slide the lens inside the chassis, or to physically turning the whole projector so that it projects at a slightly different angle? I can see how the latter will cause a trapezoidal image, but why the former?

I am not the engineer, so I will answer as best I can.

Because a horizontal expansion lens expands light in the horizontal direction, it is important that the light source be centered in the optics or there will be an uneven spread. Light source placement in the vertical is a non-issue, since the lens does not affect vertical size or geometry.

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post #18 of 31 Old 02-11-2013, 11:09 AM
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Quote:
Originally Posted by DL4567 View Post

Well, I've bought the bullet and ordered a 2.35 screen. Monoprice had the exact size I wanted to maintain the same height as my current 16:9 screen. So I'm pretty much "locked in" to that aspect ratio now.

I see the point of those that say a lot of movies are actually 2.37 or 2.4, but 2.35 is the most popular number that we all know, it's the name of this section of the forum, and it's sold by tons of screen companies, whereas you don't see many off-the-shelf 2.4 screens.

My main reason for asking is that I was just alarmed that (based on my quick hand-held test) the lens is expanding my 16:9 image to what I approximate to be about 2.45:1, in my case about 3" of overshoot on each side with the top and bottom lined up. I was just wondering if this is due to my really short throw ratio of 1.5.
The overshoot on the sides is not the end of the world however, since I'm running my movies through an HTPC, which gives me great flexibility in scaling the image. I can just squeeze it a bit horizontally to make it fit the 2.35 screen exactly, which should look correctly proportioned.

As for horizontal shift, my projector is square/plum/level/perpendicular to the screen, just as the manufacturer recommends. The lens shift dial is turned to accommodate my projector being 9 1/2" off center from the screen. Naturally, the middle-line of the room was a space between ceiling joists rather than a nice joist to screw into, so I had to go a bit to the side with my projector mount.

You are correct that the issue has to do with the very short throw ratio. Hopefully once you have everything setup you can compensate for the issues that come along with that. I am most concerned with the horizontal lens shift, actually. How hard would it be to build a bracket to attach the lens mount to? And, if you have to do something like that, would you be able to increase your throw ratio a bit along with that?

Hopefully everything will line up and work out fine and further adjustments will not be necessary smile.gif

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post #19 of 31 Old 02-11-2013, 11:12 AM
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Quote:
Originally Posted by DL4567 View Post

Good to hear someone else has had the same experience. I just wanted to be sure it wasn't from the horizontal lens shift. While I *could* center the projector, it would be a lot of trouble and I'd be miffed if it didn't make a difference.

Best advice here is to try it and see. My prediction would be that the lens shift issue is the one with the greatest potential for problems, though.

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post #20 of 31 Old 02-11-2013, 11:38 AM
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Originally Posted by coolrda View Post

I think Panamorph used to recommend a minimum of 1.7x for that lens. Thats the advantage of cylindrical, keeping geometry and focus at the extremes of throw.

First of all, I want to point out that the UH380 is a cylindrical / prismatic hybrid, not a straight prismatic.

Geometry on a "pure" cylindrical lens is also affected by throw ratio. It is true, however, that the change in geometry is slightly less than with the UH380 design. Of course, this is only an issue when the lens is installed outside the recommended ratio and distance.

RE: focus on a cylindrical lens. It is true that cylindrical lenses can be focused in much the same manner as a camera lens. It is also true that the Panamorph design - at least the one used in the UH380, UH480, and DC1 - is a "fixed focus" system, but one that is far more forgiving of placement regarding focus. For example, the aforementioned Panamorph lenses (380 / 480 / DC1) can deliver graphics level, extreme pixel clarity with test patterns at approximately 14.5 to 17.5 feet without any need for focus adjustment. When discussing HD video content and normal viewing distances, these designs have an effective focus range of about 12 - 22 feet. For distances outside those parameters, Panamorph sells custom corrector kits to fine tune focus for other throw distances.

All of that said, every lens has a "sweet spot," a distance at which it performs optimally regardless of focus adjustment. With the Panamorph design discussed above, that distance is 14.5 - 17.5 feet. While a "pure" cylindrical lens has the ability to be focused at a greater range of distances, all that that means is that the "pure" cylindrical lens has greater flexibility to work outside of its sweet spot. The Panamorph design, by allowing for different corrector elements to be installed depending on throw distance, allows for the creation of a new sweet spot - one designed around the specifics of the individual installation. While adding the corrector does add to the cost of the lens system, in most cases even when you add the cost of the corrector to the Panamorph system as a whole, you are still at a lower price point that the cost of many "pure" cylindrical lens systems.

Lastly, in regard to the "1.7x" throw recommendation, it is actually 1.6x, but that's cool - close enough. I just want to point out, though, that the throw ratio recommendation has everything to do with reducing pincushion and nothing to do with focus. Pure cylindrical lenses also suffer from more pincushion at shorter throw ratios.

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post #21 of 31 Old 02-11-2013, 01:23 PM
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For my UH380 I made this study to guide me 4 years ago.
SonyVPL-VW60Analysis.JPG

Here is the excel file, input your PJ limits and then find your sweet spot! Have fun
SonyVPL-VW60 LensAnalysis.zip 12k .zip file t!
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post #22 of 31 Old 02-11-2013, 01:25 PM
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For my UH380 I made this study to guide me 4 years ago.
SonyVPL-VW60Analysis.JPG

Here is the excel file, input your PJ limits and then find your sweet spot! Have fun
SonyVPL-VW60 LensAnalysis.zip 12k .zip file t!

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post #23 of 31 Old 02-11-2013, 01:41 PM
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Because a horizontal expansion lens expands light in the horizontal direction, it is important that the light source be centered in the optics or there will be an uneven spread. Light source placement in the vertical is a non-issue, since the lens does not affect vertical size or geometry.

Theoretically, wouldn't moving the horizontal-expansion lens to line up with the light source be an easy fix for that, without having to change the physical position of the projector?

(As John knows) I'm in the process of building a new home theater. My HT installer already put the mount on the ceiling. Due to some unexpected unevenness in the symmetry of the room, the projector didn't line up precisely with the screen. That mount is fixed and ain't movin'. My only options are changing the angle of the projector (bad for geometry) or lens shift.

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post #24 of 31 Old 02-11-2013, 02:26 PM
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Theoretically, wouldn't moving the horizontal-expansion lens to line up with the light source be an easy fix for that, without having to change the physical position of the projector?

(As John knows) I'm in the process of building a new home theater. My HT installer already put the mount on the ceiling. Due to some unexpected unevenness in the symmetry of the room, the projector didn't line up precisely with the screen. That mount is fixed and ain't movin'. My only options are changing the angle of the projector (bad for geometry) or lens shift.

Problem there is that the image will just slide off the edge of the screen (if I am understanding you correctly).

An inch or two should not really make a difference, but the 10" mentioned by the OP could be an issue.

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post #25 of 31 Old 02-11-2013, 04:52 PM
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Problem there is that the image will just slide off the edge of the screen (if I am understanding you correctly).

Would it? I'm talking about moving the whole lens horizontally (as in, on the sled mount) to put it in the center of the light path, rather than moving the projector. When you said earlier "it is important that the light source be centered in the optics," were you talking about the HE lens' optics or the projector's optics?

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post #26 of 31 Old 02-11-2013, 09:49 PM
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Originally Posted by Josh Z View Post

Would it? I'm talking about moving the whole lens horizontally (as in, on the sled mount) to put it in the center of the light path, rather than moving the projector. When you said earlier "it is important that the light source be centered in the optics," were you talking about the HE lens' optics or the projector's optics?

By using horizontal lens shift on a projector you are basically sending the image through the anamorphic lens on an angle. This means that one side of the image will have greater distortion than the other side, making the image asymmetric. Angling the anamorphic lens relative to the screen can somewhat mitigate this but adds other aberrations at the same time. Consequently, it’s best to stay on center with the screen as much as possible.

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post #27 of 31 Old 02-12-2013, 03:04 AM
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Wow. Want a job? wink.gif

You know what they say....even a hobby becomes a job when it's "the job".
I hope by making text graphical people can grasp easily stuff and help with their decision making, so over the past 3-4 years I've re-posted that graph and chart a few times.
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post #28 of 31 Old 02-20-2013, 11:26 PM - Thread Starter
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Been a while since I chimed in here, just wanted to give a little update. I mounted my UH380 and sled to the ceiling early last week, and the new 150" 2.35 screen arrived Friday and I got it set up over the weekend. After slotting out a couple of the holes in the sled mount, I was able to tweak the angle and position of the lens and watched a couple of movies already. Bottom line... I'm THRILLED with the results. The transition to a scope screen that has the same height as my previous 16:9 screen is even better than I was anticipating. smile.gif

As for the horizontal projector lens-shift debate, when I displayed an anamorphic test pattern to do fine adjusting of the lens, the two circles on the left side of the screen (further away from the off-center projector) do look *slightly* wider than the circles on the right side (closer to the projector). I guess this is certainly a symptom of the lens shift. However, it is so slight that it's only noticeable when analyzing the test pattern, and I'm actually rather blown away at how well I was able to get the test pattern centered and symmetrical on the screen. I will get a picture of the test pattern next time I watch a movie and post it for you guys.

I can't begin to explain how happy I am with the new setup, and the quality of the UH380 is amazing. No disappointments or regrets about not getting that used ISCO 2 instead. Thanks all you guys for your replies and guidance, especially John S. I really appreciate you taking the time to type out some of your knowledge. Josh Z, it's cool to see you post in this thread, as I really enjoyed your CIH articles on your site. They were an excellent read as I was educating myself on CIH over the last few weeks. And mtbdudex, very impressive work with that spreadsheet!
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post #29 of 31 Old 02-22-2013, 03:07 PM
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Thrilled that you are thrilled! smile.gif

Happy to help. And very glad to hear that the horizontal offset hardly affected the image at all.

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post #30 of 31 Old 02-23-2013, 11:16 AM - Thread Starter
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Promised pic of test pattern, and of course a screenshot. smile.gif




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