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camus2010 09-17-2013 04:09 PM

Greetings everyone! This is my first post on this forum although I have been reading articles here for a few years smile.gif. I am building a home theater in a basement room and I would like to hear suggestions on the equipments. The room measures 16' by 18' and has total light control. My current plan is to use a large 2.35:1 fixed screen on the 16' side. The models in my mind right now are the DaLite Cinema Contour 65"x153", or the Elite Screens Lunette series of similar size. Due to the short throw distance, I would also need an anamorphic lens since zooming might not be adequate. The total budget for the screen, projector, and anamorphic lens is around 10k (for now). Is this a practical setup (and a realistic budget) to get a "reasonably good quality" picture? I know this is subjective but I am not very picky on image. My six years old Panasonic PT-AX200U projected on a white wall makes me pretty happy to this day smile.gif Any input is highly appreciated! Thank you!

Seegs108 09-17-2013 04:21 PM

You may want to reconsider the anamorphic lens option. I say this because unless you get an ISCO IIIL lens almost all others require a minimum throw distance of atleast 2:1 in relation to screen width for the lens to function ideally. This means you'd need to have a screen width of less than 9' which is probably a lot smaller than you wanted to go judging from your "large 2.35:1 fixed screen" statement.

AV Science Sales 5 09-17-2013 04:33 PM

Quote:
Originally Posted by Seegs108 View Post

You may want to reconsider the anamorphic lens option. I say this because unless you get an ISCO IIIL lens almost all others require a minimum throw distance of atleast 2:1 in relation to screen width for the lens to function ideally. This means you'd need to have a screen width of less than 9' which is probably a lot smaller than you wanted to go judging from your "large 2.35:1 fixed screen" statement.

Or you use a curved screen, like I do. Ideally, you would want a screen with around a 41' radius.

OP'er, I will send you a PM. smile.gif

camus2010 09-18-2013 08:20 AM

Thank you for the replies! Let me make my questions more specific:
1. Will the curved screen solve the problem with short throw and A-lens, assume that's all about push-pin?
2. Among the three candidates I am considering (Panny PT-AE8000, Sony VPL-HW50ES, Epson 6020UB), which is the best to drive a 170" screen? (assuming 80% 2D movie, 10% 3D movie, 10% gaming)
3. I have no experience with high gain screens. If one sits close to the screen and off center, will the image becomes noticeably dimmer (like a highway reflector)?

AV Science Sales 5 09-18-2013 08:40 AM

Quote:
Originally Posted by camus2010 View Post

Thank you for the replies! Let me make my questions more specific:
1. Will the curved screen solve the problem with short throw and A-lens, assume that's all about push-pin?
2. Among the three candidates I am considering (Panny PT-AE8000, Sony VPL-HW50ES, Epson 6020UB), which is the best to drive a 170" screen? (assuming 80% 2D movie, 10% 3D movie, 10% gaming)
3. I have no experience with high gain screens. If one sits close to the screen and off center, will the image becomes noticeably dimmer (like a highway reflector)?

1. Curved screen helps with the pincushion problem.
2. If you use a screen with 1.3/1.4 gain, only the Sony has enough lumens in best image mode to light up that size screen. If you use the higher output modes, then all three can light up that size screen. If you use a High Power screen with it's restricted low mounting point, then all three can light up that screen in best image mode.
3. With a high gain screen you do lose some brightness, but generally, if you are seated between the edges of the screen, this is not a problem. Even when seated a little outside the screen, most do not have a problem.

You have to look at projector and screen as a combination to get a good fit. Budget is usually the limiting factor. If you want 3D at that size, then you are going to need high gain, like the High Power screen.

mark haflich 09-18-2013 08:44 AM

The HP I don't think is available curved.

camus2010 09-18-2013 09:09 AM

Doesn't the Sony has lower lumen (1700) than the Panny and Epson (2400)? Correct me if I am wrong ...

mark haflich 09-18-2013 09:56 AM

the real consideration is calibrated lumens. Abd then it is VERY important that in order to see say double the brightness, the calibrated lumens mustbe quadrupled. Basicall if one machine has say 300 lumens more than a machine that puts out say 1000 calibrated lumes, you are talking only less than a 5% difference to your eyes.

AV Science Sales 5 09-18-2013 10:25 AM

Quote:
Originally Posted by camus2010 View Post

Doesn't the Sony has lower lumen (1700) than the Panny and Epson (2400)? Correct me if I am wrong ...

Depends are what you measure. Rated lumens from a manufacturer are just for bragging rights when it comes to 2D picture quality. So if you are looking for the best out of a projector, you would look at lumen output in calibrated, best image mode. Usually that is measured in high lamp and mid zoom. Here are the lumen numbers for all three measured by the same person on the same screen:

Panny, 602: http://www.projectorreviews.com/panasonic/pt-ae8000/performance.php#bright
Epson, 678: http://www.projectorreviews.com/epson/home-cinema-5020/performance.php#bright
Sony, 992: http://www.projectorreviews.com/sony/hw50es/performance.php#bright

As you can see the Sony is about 165% brighter than the Panny.

mark haflich 09-18-2013 10:31 AM

About 13% brighter to one's eyes.

camus2010 09-18-2013 11:59 AM

That clarifies the issue. Thanks! I guess I would go for the HW50ES (or wait for HW55ES?) then.
Now back to the question: to couple with this projector at a short throw (~17'), what is the most suitable combination of the A-lens and screen with my remaining budget of 6k? Are HP and curved screen mutually exclusive, as Mark suggested?

mark haflich 09-18-2013 12:40 PM

Quote:
Originally Posted by camus2010 View Post

That clarifies the issue. Thanks! I guess I would go for the HW50ES (or wait for HW55ES?) then.
Now back to the question: to couple with this projector at a short throw (~17'), what is the most suitable combination of the A-lens and screen with my remaining budget of 6k? Are HP and curved screen mutually exclusive, as Mark suggested?

Forget an A lens at anything but long throw. You must keep the exit image coming out of the projector lens as small as possible and then mount the A lens as close as possible to the exit glass. Not to mention the pin cushioning. Forget the A lens.


HP is a fabric that must not be tensioned.

Drexler 09-18-2013 01:25 PM

You can get a curved hp screen. I was about to order a custome one a couple of years ago and got a quote from da-lite that wasn't that expensive. I moved again soon after so i never ordered it. Send da-lite a mail and ask.

AV Science Sales 5 09-18-2013 01:27 PM

Quote:
Originally Posted by mark haflich View Post

The HP I don't think is available curved.

Just now getting back to this thread. You are correct HP is not available on a curved screen. I got caught up in the needed gain and forgot about the curve. The HP fabric is fiberglassed backed and does not stretch much at all, so it will not work on the curved frame.

AV Science Sales 5 09-18-2013 01:29 PM

Quote:
Originally Posted by Drexler View Post

You can get a curved hp screen. I was about to order a custome one a couple of years ago and got a quote from da-lite that wasn't that expensive. I moved again soon after so i never ordered it. Send da-lite a mail and ask.

Someone at Da-Lite was making a mistake. That fabric will not lay properly on a curved frame, due to lack of stretch in the material. Also the high gain of the HP on the curve might cause some washout.

AV Science Sales 5 09-18-2013 01:33 PM

Quote:
Originally Posted by mark haflich View Post

Forget an A lens at anything but long throw. You must keep the exit image coming out of the projector lens as small as possible and then mount the A lens as close as possible to the exit glass. Not to mention the pin cushioning. Forget the A lens.


HP is a fabric that must not be tensioned.

For those with depth challenged rooms that want screens wider than the projector can zoom, we have no choice. I have such a setup and my image is nice and sharp. It does required a curved screen to help with the pincushion. I would not even consider going back to my smaller flat screen.

Drexler 09-18-2013 01:39 PM

Quote:
Originally Posted by AV Science Sales 5 View Post

Someone at Da-Lite was making a mistake. That fabric will not lay properly on a curved frame, due to lack of stretch in the material. Also the high gain of the HP on the curve might cause some washout.
The high gain actually helps and decreases the washout from the curve. i got a quote including an engineering drawing of the custom screen with the material snapped on to the screen. Think about it, why would you need to tension a curved screen any more than a flat?

AV Science Sales 5 09-18-2013 02:09 PM

With an 18' deep room, your max throw is going to be around 16'-4". If trying to keep the throw ratio a minimum of 2.5 to reduce pincushion to about 5/16" , you would have to go with a screen that is no wider than 106".

camus2010 09-18-2013 02:17 PM

For curved screen, what's the highest gain one can get at the current market?

AV Science Sales 5 09-18-2013 02:24 PM

Quote:
Originally Posted by Drexler View Post

The high gain actually helps and decreases the washout from the curve. i got a quote including an engineering drawing of the custom screen with the material snapped on to the screen. Think about it, why would you need to tension a curved screen any more than a flat?

A fixed frame screen is a tensioned screen. US Da-Lite will not make it.

AV Science Sales 5 09-18-2013 02:25 PM

Quote:
Originally Posted by camus2010 View Post

For curved screen, what's the highest gain one can get at the current market?

What you can get and what you should get are not the same. Probably could get a high gain curved screen, but does not mean that you should get such an animal.

camus2010 09-18-2013 02:39 PM

Quote:
Originally Posted by AV Science Sales 5 View Post

What you can get and what you should get are not the same. Probably could get a high gain curved screen, but does not mean that you should get such an animal.
Then which attribute should I sacrifice? Curve or high gain? Or shall I just get a flat 1.3 screen and ignore the pin cushion issue?

mark haflich 09-18-2013 02:59 PM

Its all not relevant. YOU CAN'T USE SHORT THROW WITH AN A LENS!. If you want to discuss call me.

AV Science Sales 5 09-18-2013 04:31 PM

Quote:
Originally Posted by mark haflich View Post

Its all not relevant. YOU CAN'T USE SHORT THROW WITH AN A LENS!. If you want to discuss call me.

That is about like saying you can't use a flat screen with an A-lens, because you are always going to have pincushion with a flat screen. You can reduce the amount of pincushion on a flat screen by increasing the throw distance, but you can't get rid of it. Now you can get rid of the pincushion by curving the screen. The shorter the throw and or larger the screen the more curvature is needed to get rid of the pincushion. Here is an article about curved screens and A-lens by Dennis Erskine: http://www.stewartfilmscreen.com/white_paper/curvedscreens_derskine_wp.pdf[/URL

Here is a quote from the article:

"As a result of the anamorphic lens, a type of distortion called “pin cushion” appeared. The shorter the throw distance of the projector, the greater the pin cushion. Back in the days of the CRT, pin cushion was easily fixed, but digital projectors do not have a means to correct for pin cushion (and didn’t need it until I started mucking with the optics by adding an anamorphic lens). Once again, with a little experimentation and a short conversation with Stewart Filmscreen, the problem was solved. The solution was to curve the screen! Pin cushion gone, and a gorgeous Cinemascope presentation, just like the director wanted, resulted."

Granted the best solution would be long throw and a curved screen, but like everything else in HT, there is always compromise. Often times compromise is because of the room.

mark haflich 09-18-2013 04:57 PM

The problem is not pin cushioning. Its going through the sweat spot of the anamorphic and that is critical. At short throw the exit image from the primary will be big and will get bigger until it hits the back surface of the aanamorphic. That's why one wants to mount the rear surface of the anamorphic very close to the exit glass of the projector lens and why projectors with lenses recessed are not a good idea for use with an anamorphic.

That said, you can check with the specs and mounting instructions for your candidate A lens. sometimes these are not clear so check with someone like Mike who will have the minimum recommended throw, usually expressed by x times the 1.78 width of your screen (that size fits within your 2.35 or so screen.

AV Science Sales 5 09-18-2013 06:49 PM

Quote:
Originally Posted by mark haflich View Post

Rge problem is not pin cushioning. Its going through the sweat spot of the anamorphic and that is critical. At short throw the exit image from the primary will be big and will get bigger until it hits the back surface of the aanamorphic. That's why one wants to mount the rear surface of the anamorphic very close to the exit glass of the projector lens and why projectors with lenses recessed are not a good idea for use with an anamorphic.

With a deeply recessed lens it could be a problem, but with the larger A-lenses of today I think it is less of a problem. As an example, I have a JVC and an A-lens. I am shooting a 107" wide image and am using a throw of 10'-9". My image is very sharp. I have looked at the zoomed image and it sure did not look any sharper to me. At 16'-4" and shooting a 63" high 16:9 image (height of 160" diagonal 2.35), The projector (Sony HW50ES) is toward the long end of the throw. The range is 12'-10" to 19'-7". How is that any worse than using the zoom method. With the zoom method the longest available throw for the 63" high 16:9 image is 19'-10". 19'-10" for the 63" high 2.35 image (zoom method) is a lot closer to the short end of the zoom range than the A-lens setup. A-lens setup is toward long side of the zoom range and zoom method set up is getting close to extreme short throw. With the zoom method the 63" high 2.35 throw range is 17'-2" to 26'-3". Note how close 19'-10" is to the short end of the throw and that is using the absolute longest throw you could use with a zoom setup on a 160" diagonal 2.35 screen. So that means the image going thru the projector lens is much, much larger than what passes through the projector lens when using an A-lens, so the image coming out of the projector should be better, per your argument of smaller image hitting projector lens. Now the image has to pass through the A-lens and it will lose some of that gained sharpness advantage, but as long as the entry image hitting the lens fits and the lens is good quality, I don't think you are losing much if anything. Keep in mind, people are not going to use the extreme throw range of the 16:9 image and that means an even larger image hitting the projector image for 2.35.

mark haflich 09-18-2013 07:24 PM

There is another consideration and I think you will see this if you look at sharpness away from screen center. A projector lens has great depth of field. This means if you put a piece of paper up at your screen surface with the lens focused you can move the piece of paper quite a distance closer to the projector and you will still be in focus. Projector lens are designed this way in consideration of the considerable changes in distance from the screen extremities as compared to screen center. When you place an anaphoric in front of the lens, the depth of focus drops to a few enches. try it. Its a fact and the image will not be in sharp focus as you move away from screen center. that is why Joe Kane will never endorse the use of an anamorphic lens. By curving the screen you can reduce the disparity in focus lthough to completely eliminate it your screen would have to be deeply curved and you would also need a Torus screen to equalize te to and bottom distances to make them the same screen center. This will introduce unsolveable issues with the sound ofte best ameliorated by placing the center channel in the rear of the theater and aiming it at the screen.

AV Science Sales 5 09-18-2013 08:10 PM

Quote:
Originally Posted by mark haflich View Post

There is another consideration and I think you will see this if you look at sharpness away from screen center. A projector lens has great depth of field. This means if you put a piece of paper up at your screen surface with the lens focused you can move the piece of paper quite a distance closer to the projector and you will still be in focus. Projector lens are designed this way in consideration of the considerable changes in distance from the screen extremities as compared to screen center. When you place an anaphoric in front of the lens, the depth of focus drops to a few enches. try it. Its a fact and the image will not be in sharp focus as you move away from screen center. that is why Joe Kane will never endorse the use of an anamorphic lens. By curving the screen you can reduce the disparity in focus lthough to completely eliminate it your screen would have to be deeply curved and you would also need a screen which is parabolic or whatever its called to equalize te to and bottom distances to make them the same screen center. this will introduce unsolveable issues with the sound oftem best ameliorated by placing the center channel in the rear of the theater and aiming it at the screen.

Now you are talking about a TORUS screen. Technically you are correct, the screen should be curved top to bottom also, but we are talking much smaller screens for home use, so this error is very small.

Seegs108 09-18-2013 08:15 PM

I'm kind of in agreement with Mark here. If you're going to spend thousands more for an anamorphic lens you may as well get it set up properly otherwise I'd look into a prime lens with enough zoom on it to do the zoom method instead. I think the end result will look better as long as you have enough brightness left to give you a satisfying image.

mark haflich 09-18-2013 11:38 PM

Thanks Mike. I couldn't remember torus. I edited my post.

So let's sum it up. If you add a horizontal stretch anamorphic and do a vertical scaling stretch on wide screen material, you get about 25% extra brightness to light up your screen. This will increase the brightness to your eyes about 6%.. That's about the total positive.

The negatives some of which can be ameliorated by ideal set up and a curved screen but not eliminated are:

A 5% loss in ANSI contrast
The negatives effect of scaling vertically with a non simple scale ratio
An almost complete loss of depth of field with consequent effects on screen focus as one moves away from screen center
Geometric pin cushioning.

Standard screen radiuses are not curved enough for most throws.
Pin cushioning will be ameliorated with a curve screen but to hide all pin cushioning the image will have to be over scanned eliminating part of that precious extra light the anamorphic gives you.

Spherical or rather circular anamorphics perform best when the entry image is small and this optimized requires set up at long throw.

If you starts with a projector that does not have a really good lens, the deterioration caused by the anamorphic glass is I suppose tolerable. With a great projector lens, an anamorphic will throw away some of the lens performance you are paying for.

To minimize this, one should use an expensive ISCO anamorphic and use optimum set up (long throw) and a curved screen although the ideal curved screen with need a custom curvature rather than one of the two off the shelf available.

I am sure I am missing other things.

If you decide to use an anamorphic for whatever reason, If you are starting with a 4K projector, you need a really expensive anamorphic rated at 4K and horizontally stretching at 1.25 instead of 1.33. Regardless of display resolution, one should use a curved screen and use as long as throw as one has available and the projector permits. If brightness is a problem employ screen gain in moderation (I would not exceed 1.3) and as necessary reduce screen size.

Please feel free to modify this list and correct any errors I may have stated.

In my day I have sold many anamorphics and have installed many. Most have been ISCO's and all have been at close to longest throw with and with out a curved screen. The results have been good but with compromised set up, I don't know.


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