My room has a short throw ( 13' ). Seems I'll be mounting on the back wall to get the biggest picture with my CIH setup.

What are the advantages/disadvantages to the ceiling mount vs. shelf mount.

I haven't yet picked a projector yet, and was wondering about these two methods. I know it will be either DLP or LCD as I now have an older CRT projector I'll be getting rid of.

As of now i feel the screen is a little high for me. With a constant 2.35:1 image I want a lower screen than I have now (which is a 1.78:1). The new screen will be a SMX AT.

Thanx for the help. KG

Well, Shelf mounting tends to be easier than ceiling mounting.

Depending on the projector you decide to get, could decide this for you anyways. If you go with a projector that that has little to no lens shift you will be placing it on the ceiling to get the screen to the correct level that you want.

DLP's tend to have less lens shift, some have 0 lens shift, which would prevent the shelf mounting.

Ceiling mounting also helps to keep people out of the path of the projected screen when people stand up. If you are going to be adding on a Anamorphic lens you will more than likely be mounting two devices to the ceiling instead of one which will also increase the complexity of mounting.

The other, third option, would be to mount the PJ UPSIDE DOWN to the shelf, it that would make positioning easier.

I have a comment on shelf mounting. I have the panasonic 100U and have it shelf mounted in a box on the ceiling. My ceiling is about 7.5 feet high, the screen is 92 inch diag, mounted about a foot from the ceiling. The projector box shelf is about 5 inches from the ceiling. With my situation, I have to place a 1/4 inch wood block under the rear foot of the projector to get the picture to be low enough for the screen. This results in having to use a tiny bit of keystone (I know, it's a sacrilage (?sp)).

My picture is still perfect in my eyes, but if I could do it over again (which I may redo it), I would mount it upside down in the box on the celing, not on the shelf in the box.

You will never ever be able to use a DLP in a high shelf because of the lense shift issue. My LCD has a great lense shift, but still not enough in my situation. If you must shelf mount, stick with LCD's and/or consider upside down mounting solutions.

Pat

I have a Mitsubshi HC3000 ceiling mounted in a basement dedicated theater room. The one disadvantage I see is the ceiling tends to move a bit when people are walking around upstairs. This can result in a stomach churning shake of the image on my screen.

In my case there are only two people in the house and both of us are typically watching at the same time. I can see this being a problem with larger families where not everyone may be interested in watching at once.

I also wonder if the shaking could have any long term effect on the projector's reliability. It will be subject to that motion anytime someone is walking on the floor above - though it's usually off.

I have 9' ceilings in my room, if this matters.

The DLP projector part I don't understand. Wouldn't ceiling mounting create more problems and diffeculty, or is it the ability of the mount to move that makes it easier than being on a shelf.

I am concerned with lowering the whole screen so the image is more infront of me than up higher on the front wall. I like the idea of ceiling mounting (keeping it out of the way.

There is no problem with mounting the two devices (PJ & lens assembly) on a ceiling mount.Easier said than done I'm sure.

I have 9' ceilings in my room, if this matters.

The DLP projector part I don't understand. Wouldn't ceiling mounting create more problems and diffeculty, or is it the ability of the mount to move that makes it easier than being on a shelf.

I am concerned with lowering the whole screen so the image is more infront of me than up higher on the front wall. I like the idea of ceiling mounting (keeping it out of the way.

There is no problem with mounting the two devices (PJ & lens assembly) on a ceiling mount.Easier said than done I'm sure.


DLP's generally have no lense shift, necessitating them to be mounted nearly in front of the screen. LCD's usually have lense shifts, which makes the mounting more flexible.

In your situation, you would likely be best going with something that has a nice lense shift.

Pat

I have 9' ceilings in my room, if this matters.

The DLP projector part I don't understand. Wouldn't ceiling mounting create more problems and diffeculty, or is it the ability of the mount to move that makes it easier than being on a shelf.

I am concerned with lowering the whole screen so the image is more infront of me than up higher on the front wall. I like the idea of ceiling mounting (keeping it out of the way.

There is no problem with mounting the two devices (PJ & lens assembly) on a ceiling mount.Easier said than done I'm sure.
When you set a PJ on a table and project an image you will see one of two results:

DLP: The bottom of the image on the wall/screen is above the projector. This is called "Image Offset". The affordable DLPs have no ability to "shift" the front lens in order to bring that image down to straight across from the PJ. The offset is usually enough that when you get high enough, the image would be up on the ceiling. So, the PJ has a "ceiling" mode where the PJ can be mounted upside down and the image will still be projected right side up. Now, the image is below the projector. You typically need a ceiling height of 8 feet or more to use these models, like the Mitsubishi HD1000u or the Optoma HD70.

LCD: The image on the wall/screen is straight across from the PJ, sometimes in the center, sometimes a little higher or lower but the PJ is still inside the area that the image occupies. This allows you to mount your PJ right side up behind you just a little higher and then you just shift the lens to bring the image lower on the wall or screen. Most LCD PJs have lens shift - most have vertical, some also have horizontal lens shift. Horizontal shift allows you to project to the right or left of center from the PJ. LCDs with lens shift give you greater options for difficult rooms or low ceilings like basements.

Note: If your lens shift is less than 50%, you cannot get the image completely above/below the PJ lens, the PJ will always be somewhere straight across form the image, higher or lower than center.

My room has a short throw ( 13' ). Seems I'll be mounting on the back wall to get the biggest picture with my CIH setup.

What are the advantages/disadvantages to the ceiling mount vs. shelf mount.

I haven't yet picked a projector yet, and was wondering about these two methods. I know it will be either DLP or LCD as I now have an older CRT projector I'll be getting rid of.

As of now i feel the screen is a little high for me. With a constant 2.35:1 image I want a lower screen than I have now (which is a 1.78:1). The new screen will be a SMX AT.

Thanx for the help. KG

Be sure to look for a digital PJ that will perform the vertical stretch part of your CIH function so that you only need the anamorphic lens to do the horizontal stretch to give you your CIH 21:9 image. If the PJ does not do the vertical stretch, you will need a separate video processor or htpc to do that for you.

I have 9' ceilings in my room, if this matters.

The DLP projector part I don't understand. Wouldn't ceiling mounting create more problems and diffeculty, or is it the ability of the mount to move that makes it easier than being on a shelf.

I am concerned with lowering the whole screen so the image is more infront of me than up higher on the front wall. I like the idea of ceiling mounting (keeping it out of the way.

There is no problem with mounting the two devices (PJ & lens assembly) on a ceiling mount.Easier said than done I'm sure.


9' ceilings are taylor made for a projector like the HD80. A match made in heaven actually. :)

The other, third option, would be to mount the PJ UPSIDE DOWN to the shelf, it that would make positioning easier.

This is what I would recommend as well.

With the average weight of the digitals being 20lbs or less, I can't see this being a problem and will give you the most versatility.

I will be mounting mine inverted on a shelf above the viewers heads.

Shelving systems can also be used as makeshift component housings so most of the video wiring is a short and simple run to the projector. Ceiling mounts will usually require either dangling wires or several feet of snakes twisting through and around your walls/ceilings. Just depends on how much effort or money you want to invest

When you set a PJ on a table and project an image you will see one of two results:

DLP: The bottom of the image on the wall/screen is above the projector. This is called "Image Offset". The affordable DLPs have no ability to "shift" the front lens in order to bring that image down to straight across from the PJ. The offset is usually enough that when you get high enough, the image would be up on the ceiling. So, the PJ has a "ceiling" mode where the PJ can be mounted upside down and the image will still be projected right side up. Now, the image is below the projector. You typically need a ceiling height of 8 feet or more to use these models, like the Mitsubishi HD1000u or the Optoma HD70.

LCD: The image on the wall/screen is straight across from the PJ, sometimes in the center, sometimes a little higher or lower but the PJ is still inside the area that the image occupies. This allows you to mount your PJ right side up behind you just a little higher and then you just shift the lens to bring the image lower on the wall or screen. Most LCD PJs have lens shift - most have vertical, some also have horizontal lens shift. Horizontal shift allows you to project to the right or left of center from the PJ. LCDs with lens shift give you greater options for difficult rooms or low ceilings like basements.

Note: If your lens shift is less than 50%, you cannot get the image completely above/below the PJ lens, the PJ will always be somewhere straight across form the image, higher or lower than center.


I don't think you left a thing out ! Great explaination :)

Be sure to look for a digital PJ that will perform the vertical stretch part of your CIH function so that you only need the anamorphic lens to do the horizontal stretch to give you your CIH 21:9 image. If the PJ does not do the vertical stretch, you will need a separate video processor or htpc to do that for you.

Is this fuction called different names for different PJ ? Would be nice if it was as simple as that.

Is this fuction called different names for different PJ ? Would be nice if it was as simple as that.

On my Optoma, the mode is called LBX - it does the vertical stretch, I just need to provide the separate lens that will do the horizontal stretch. I'm not sure what some of the others call it. I know the JVC RS1 that is very popular right now does not do this - you need a separate video processor.

This is what I would recommend as well.

With the average weight of the digitals being 20lbs or less, I can't see this being a problem and will give you the most versatility.

I will be mounting mine inverted on a shelf above the viewers heads.

How are you going to do this? My projector (Panny 100U) is certainly not flat on the top making inverting it on a shelf as is less than ideal.
I am intersted, as I may try it if you have a good solution for this.
Thanks,
Pat

Your Panny 100U should have lens shift right?
You don't have to invert it at all if so. It is made with zero offset, that means with no shift it would be pointed at the middle of the screen. You can go 100% of the screen vertically either way with it.

I mounted my 1000U this way, I dropped a shelf from the ceiling as close to the ceiling as possible so I could get to the lens shift thingies, left the projector upright and lens shifted it on to my screen, no problemo.

How are you going to do this? My projector (Panny 100U) is certainly not flat on the top making inverting it on a shelf as is less than ideal.
I am intersted, as I may try it if you have a good solution for this.
Thanks,
Pat

Shelf mounting up high is usually an INVERTED shelf. You mount the PJ to the shelf by putting the mounting screws through the shelf, then flip the whole shelf over so that the PJ is upside down.

As was already mentioned, LCD PJs with adequate lens shift may not need to be flipped over like most of your DLP PJs. A shelf mount may work better for wiring and power, especially when you have a vaulted or cathedral ceiling.

Your Panny 100U should have lens shift right?
You don't have to invert it at all if so. It is made with zero offset, that means with no shift it would be pointed at the middle of the screen. You can go 100% of the screen vertically either way with it.

I mounted my 1000U this way, I dropped a shelf from the ceiling as close to the ceiling as possible so I could get to the lens shift thingies, left the projector upright and lens shifted it on to my screen, no problemo.

It does, and it's all the way down still requiring about 1/4 inch elevation of the rear of the projector to fit the screen. Then I use a little bit of keystone correction.
If I could invert the projector, the lense shift would be more than adequate. It seems that the lense shift on the projector is made for two cases:
1. shelf mounting for those who need to shift up
2. inverted ceiling mounting for those who need to shift down

I have a third case, shelf mounting and needing to shift down , which it doesn't have enough shift to do.

Pat

Shelf mounting up high is usually an INVERTED shelf. You mount the PJ to the shelf by putting the mounting screws through the shelf, then flip the whole shelf over so that the PJ is upside down.

As was already mentioned, LCD PJs with adequate lens shift may not need to be flipped over like most of your DLP PJs. A shelf mount may work better for wiring and power, especially when you have a vaulted or cathedral ceiling.

Yep. Before we put the bottom on the box, we should have mounted it INVERTED to the top of the box.

Mounting it to the bottom of the box now would not be asthetically acceptable.

As was mentioned by me before, the lense shift on the panny is generous, but still does not allow for proper right side up mounting in my situation.

I basically need an on ceiling, in-box, inverted, low profile mounting solution. I was under the impression that the lense shift would make my situation work without issues, so I am trying to warn people that it may not work for them either.

For the record, I am quite happy with my setup and the picture looks great. I just wish I didn't have to use any keystone.

Pat

Would you relate keystoning adjustments to using a parametric EQ on your mains.The idea is to keep as much (in terms of adjustments ) out of the way as possible ?

kg

Digital keystone correction (DKC) is a scaling process taken by the projector to compress some of the original signal pixels and expand other original signal pixels in order to achieve the projected beam shape in order to APPEAR perfectly vertical or horizontal on your screen. By squeezing and stretching pixels to create the proper shape, you can introduce aberrations in the image that can degrade your viewing experience. This effect is most obvious when projecting a computer desktop or an image with lettering on it. Because most PJs have a good processing circuit in them, the problems that can occur in DKC are minimized and most people do not see any difference under typical conditions. If you have to do it, keep it to a minimum.

It does, and it's all the way down still requiring about 1/4 inch elevation of the rear of the projector to fit the screen. Then I use a little bit of keystone correction.
If I could invert the projector, the lense shift would be more than adequate. It seems that the lense shift on the projector is made for two cases:
1. shelf mounting for those who need to shift up
2. inverted ceiling mounting for those who need to shift down

I have a third case, shelf mounting and needing to shift down , which it doesn't have enough shift to do.

Pat


Dang, what sized screen? And how far from the ceiling is it mounted. I guess I got lucky, or the lens shift on the AE1000U gives more shift perhaps? I didn't really see how much I had left though, just got in on the screen and called it good.

Dang, what sized screen? And how far from the ceiling is it mounted. I guess I got lucky, or the lens shift on the AE1000U gives more shift perhaps? I didn't really see how much I had left though, just got in on the screen and called it good.

Part of the problem with mine is that the screen has to be mounted below a soffit, but the projector box is on the ceiling (no soffit). I do have a few inches I can move up the screen on the wall despite my wife telling me to "leave it alone" :rolleyes: I may try that first. Otherwise, I found a $40 mount I believe I can fit inside the box to invert it.

Pat

Part of the problem with mine is that the screen has to be mounted below a soffit, but the projector box is on the ceiling (no soffit). I do have a few inches I can move up the screen on the wall despite my wife telling me to "leave it alone" :rolleyes: I may try that first. Otherwise, I found a $40 mount I believe I can fit inside the box to invert it.

Pat

Have you determined yet if the lens shift up is any more than the lens shift down? If not you are going to gain nothing by flipping the PJ.

Have you determined yet if the lens shift up is any more than the lens shift down? If not you are going to gain nothing by flipping the PJ.

It seems as though it is. I didn't confirm that however. If you think about it, the shift needed is the same direction for both of the "preferred" mounting options, up towards the top of the projector. I need it to go the other way:(

Pat

In the manual for my AE1000U, it has the same amount of shift available above and below so there seemed to be no benefit to inverting it whatsoever.

In the manual for my AE1000U, it has the same amount of shift available above and below so there seemed to be no benefit to inverting it whatsoever.

Huh??? Well now I'll just have to try it. Or I'll just leave my beautiful, albeit mildly keystone corrected, picture alone:D

Pat

It seems as though it is. I didn't confirm that however. If you think about it, the shift needed is the same direction for both of the "preferred" mounting options, up towards the top of the projector. I need it to go the other way:(

Pat

You are going to need to bring the box down from the ceiling some...

You are going to need to bring the box down from the ceiling some...

No, I am going to leave it alone I think :cool:

Thanks much for bringing me to this realization. I am 6'4" tall and like how high the box is. I may try to bring the screen up a bit. I think that may do it.

Pat

I may try to bring the screen up a bit. I think that may do it.

Pat

There's your answer! :)

Huh??? Well now I'll just have to try it. Or I'll just leave my beautiful, albeit mildly keystone corrected, picture alone:D

Pat


Well don't be afraid of using keystone. Most that always exclaim the evils of it would be hard pressed to tell if it was in use or not. :)

Well don't be afraid of using keystone. Most that always exclaim the evils of it would be hard pressed to tell if it was in use or not. :)

And yet it is still evil and should be avoided... :D

I use a slight amount of it and I can't see any distortions. YMMV