I was having trouble finding a pre-existing thread helping out front projector installation. I am installing and HD70 and an 92" diag screen. Think I figured out the distance from the screen the projector needs to be mounted (12.7') but don't know how low the projector needs to be hanging from the ceiling on its mount. Is there a formula i can use? The top of my screen is going to be 32" down from the ceiling.

Thanks.

I'm going through the same thing now. The projector has a massive offset. I'm going to have to end up mounting it upside down because if you put it anywhere near the ceiling, it's going to throw a picture on the ceiling itself. I guess if you can let it hang down some, it might work.....no idea how far. I'm going to try and eyeball it.

try this


http://www.projectorcentral.com/projection-calculator.cfm

I used that calculator to find the distance he projector needs to be from the center of the screen...however it does not tell you how to hang the projector itself.

In a perfect world it would be best to mount it 12.7' back in front of the dead center of the screen. This is impossible without movie-theater style terraced or stadium seating and I am assuming most do not have stadium seating in their homes.

Being totally new to FP I am assuming you mount it on the ceiling at a certain height down...that height depending on how far down the screen is from the same ceiling the proj. is mounted on. Then you would apply some sort of "offset" in the projector to shoot the image downwards. Wouldn't there be distortion in the picture? I thought you wanted to mount the projector to be absolutely square to the screen and not apply any artificial "adjustments" such as keystoning or offsets..

Thanks!

Kent
The term you are looking for is drop height and all projectors are different in that regard. The manufactures web page and the book that comes with it should provide information.

The skewed optics is built into the projector and ceiling moutn you turn the projector over. And then in the menu flip the image. If the throw distance and drop height are right you wont require keystone and keystone will affect PQ.

The other factor is the projectors zoom range so what you have is a min and max throw distance. That distance will affect brightness and also sharpness to some extent.

The last thing is the better projectors have image shift. That aids a lot in all the above.

Along with all this its important the center line of the lens is exactly centered right and left across the screen. If not you will be tempted to twist the projector to get the image centered and then you get into a area where focus is off on the sides of the image. The best way to center is with two strings coming off the top corner of the screen of the same length. Think equilateral triangle.

I’m out of time now but post back and I’ll find you some links later.

I'm going to have to end up mounting it upside down because if you put it anywhere near the ceiling, it's going to throw a picture on the ceiling itself.

You will have to ceiling mount it upside down (perfectly natural) or put it on a table shelf near the floor right side up.

I have my HD70 ceiling mounted 10.6 feet from my 90" screen. Works fine!

I was having trouble finding a pre-existing thread helping out front projector installation. I am installing and HD70 and an 92" diag screen. Think I figured out the distance from the screen the projector needs to be mounted (12.7') but don't know how low the projector needs to be hanging from the ceiling on its mount. Is there a formula i can use? The top of my screen is going to be 32" down from the ceiling.

Thanks.

Your 92" screen is 45" tall. The offset is about 30 percent so that is 14 or 15 inches. So, if your HD70 was mounted UPSIDE DOWN from the ceiling it would have to hang down a total of 18 inches to the center of the lens in order to meet your requirement of the top of the screen being 32" from the ceiling.

BTW: By adjusting the zoom ring, you can put your PJ closer to the screen than 12.7 feet.

You either have a tall ceiling or you want your screen closer to the floor!

Bud,

Thanks for your explanations! Don't think it has Image Shifting. Does "flipping" the image cause any sort of picture quality degredation compared to it being right side up? Any good/easy ways to attempt/test different throw distances?

Kinda talking to myself in the rest of the post here but would love some confirmation:

According to a projection calculator the recommended range throw range is 10.5' to 12.7' with 12.7' being the distance with zoom at 1.0X. However due to my screens .95 gain and fairly "light" room (there are dark curtains but sun does creep through) I am assuming I should try to get the throw to work at the lower 10.5' side of things...it is a Screen Research ClearPix2 white screen BTW.

reconlabtech,

Thanks! With my ceiling at 9' and screen at 32" below the ceiling (I have no choice as the wall is recessed for its current inhabitant...a 42" plasma..luckily the screen will fit right into the recessed wall with mm's to spare) I will mount it upside down as opposed to on a coffe table right-side up.

1.5 feet down is a long drop down unfortunately...the wifie ain't gonna be happy. Any recs on a motorized mount system?

Thanks!!

Hey Kent,

No problem on the help - we have all needed it from time to time!

Yes, your HD70 was designed to sit right side up on a low shelf projecting the picture up on the wall or mounted, by the provided screw holes in the bottom, upside down from the ceiling. There is a menu selection that you pick that will flip the projection so that it projects down the wall but it will be right side up when looking at it. That's how I do it.

The numbers? The HD70 officially has a 128% offset. That means the picture will be entirely above the lens (or below, from the ceiling) and 28% of the height of the picture currently being projected. 28% is barely different from 30% so if you are projecting a 92" diagonal picture, the actual height will be 45". 30% of that is 13.5" or about 14".

My ceiling mount came from mountdirect.com and came with a short mount and a foot long extension. If you get that mount, just use the extension and you should be just about where you want to be. The mount is white, the HD70 is white - they are almost unnoticeable hanging there. You just have to get your power and video cable up there! Flush mounted wire manangement can run that up the wall and hide it pretty well or you can fish it up the wall to the ceiling or down from the attic if you have one.

Don't worry about a motorized mount - just put up her favorite movie and she will forget all about the PJ hanging there and will look at it differently when the movie is over.

Ha! I think that is a good idea...will throw on something she likes :)

Thanks for the explanations.

I too like the Mountdirect NPL mount...will purchase the additional 11" - 18" ext rod. Can't beat that price and the fact that it is all white is great.

However... I hate to be a flip flopper but the only other competitor for my HD proj purchase was the HD1000U. Seems a bit brighter, has a centered lense, but lower contrast ratio and 1 year warr. My room can be fairly light during the daytime so you think the Mit's extra light output (22Fl vs 15Fl), along with the lense being centered, would be beneficial enugh to purchase it over the HD70. It seems that it may also have a larger offset allowing a shorter drop height.

I figure you may have already been through this and have a magical answer for me (aside from me going to view the two side by side and deciding that way without all these technicalities getting in the way).

I am going to go through the rigormortum of running cables through the cieling..including some romex so the unit can be plugged into my equipment power conditioner and the 12V trigger can be run to the equipment rack.

Thanks again!

OK, I was a little off with my screen dimensions :eek:

Viewable Screen Height is 39.375" and Diag is 80.3"

Also noticed Mits adds about 10 fL more in ANSI output...hmmm

Just keep in mind the Mits will offset an inch or two more than the Optoma. I bought the HD70 because it is white and blended into my ceiling better. Either will serve you well.

Yes, would require a little less of a drop. Thanks again for all the help...I know so much more then I did just a few days back because of it. Will keep you updated on what I buy....just noticed your "Location" description.. ( ;

....just noticed your "Location" description.. ( ;

It's so much more descriptive than Northern VA. I lived in San Diego and Oceanside from '83 to '94 courtesy of Uncle Sam. San Marcos was a nice area when we were there. Lots of construction going on then.

OK, I was a little off with my screen dimensions :eek:
Viewable Screen Height is 39.375" and Diag is 80.3"
Also noticed Mits adds about 10 fL more in ANSI output...hmmm

At 80" you are going to have a light cannon no matter what you put up! That picture is gonna pop!

My screen has a 2.2 gain, supposedly 35 fL at my distance! Brightness is currently set to -16 and it's still plenty bright!

Looking forward to your first show report!

Well the construction has not stopped since you were here then! It is a popular place in San Diego to live right now. Yes, had to keep the screen relatively "small" but will be twice as big as what we have now and will still keep the family room a "family room" and not dad's home theater. Also want it to "pop" as much as our current plasma or the whole reasoning for me upgrading, for a bigger AND better picture, will have been missed. May throw up some more questions come installation time so don't forget about me!

The system is installed and working great. Loving the MitsHD1500 paired with the Screen Research 80".

The screen is absolutely beautiful...sounding and looking! I opted not to use the additional black screen that came with the screen purchase (recommended by SR for minimizing light reflection from behind the screen). The frame is a 2.5" black metal finish that bevels nicely into the edges of the screen fabric. My M&K's are about 1 inch from the back of the screen and sound like nothing is blocking their way. The screen is truly acoustically transparent. I was worried about the screens lower-than-usual gain, but the lumen output of the Mits makes up for it.

Regarding the Mits PJ, I now know exactly what the rainbow effect looks like as I am a little prone to it..happens when you turn your eyes suddenly from the screen or blink. It is not annoying enough to bother in a big way though. After a few neighbors saw the result of the setup, one built the same deal at his house and the other is in the process of pricing it out! It is stunning to watch and listen to. Also ran some cable to the back wall behind my couch for the sub...you can really "feel" it now.

Even with the PJ's VERY bright output, dark scenes definitely suffer when viewing during the daytime with the uncontrolled light entering my family room. I therefor have two settings, "Daytime" which is blownout to hell and "Nighttime" which I calibrated rated using both AVS forum recs as well as my AVIA DVD. At night I am memorized by the HD films I have DVR'ed...finally the caliber of my vieing situation matches that of the audio situation. Together it is an amazing experience.


On random notes, I took some time to also run two Romex lines for both the sub and PJ back to the niche where my Monster HT5000 power conditioner resides. Now all my HT equip resides on one controlled power source which is definitely nice.

Some interesting issues on the negative side:

1 - My neck still hurts from patching and painting the 30 holes I had to put in my ceiling to pull the cables for the PJ.

2 - I have a nice slow moving purple line rolling up the screen when the component video source is selected. I was careful to avoid running the video cables near high voltage. However I did notice a small "fray" of the component cable...revealing a very small amount of the inner shielding. Must have happened while pulling.

Anyway thanks to all for your help...I could not have built this without you. i will get some pics up soon.

The purple line floating from top to bottom sounds more like a ground loop problem. Are you using the component for your cable tv feed by any chance?

Your install sounds first class.

If I may ask when you ran the romex back to your power conditioner how did you go about connecting that romex into the conditioner?

The purple line floating from top to bottom sounds more like a ground loop problem. Are you using the component for your cable tv feed by any chance?

No, using HDMI for cable....assuming I would have the same issue if I swapped cables. I did not thing it was a grounding issue as there are no other problems in the system...no audio buzz...nothing. Figured maybe that cable has faulty shielding or something. Only other component plugged into the Home theater that is NOT on the power conditioner is an Appl airport express connected to the amp via RCA cables...hmm

Your install sounds first class.

Yes, tired to keep it as first class as possible ( ;

how did you go about connecting that romex into the conditioner?

Terminated the end with a 3 prong plug and plugged it in.

BEFORE:

http://www.koberlinstudios.com/Home_Theater/060207/LG_Fam_Room.jpg

AFTER:

http://www.koberlinstudios.com/Home_Theater/110507/HomeTheater5.jpg
The M&K's finally mounted inside the wall. There are two surrounds in the back and I also ran cable (high quality shielded Mogame) and dedicated AC for the sub which now sits behind the couch...perfect spot for a sub!

http://www.koberlinstudios.com/Home_Theater/110507/HomeTheater6.jpg
Some of the gear in the niche below the screen. I have an infared eye hidden behind the screen that distributes IR to all the components tucked away in the niche....works great...a $25 solution from Home Theater Direct. Denon AVR5700 amp is SOLID and has been for the 8 years I have had it. What you don't see is the SONY 9000ES SACD/DVD player, cable box DVR, and Monster HT5000 Power Center.

http://www.koberlinstudios.com/Home_Theater/110507/HomeTheater4.jpg
The ventilation system for the gear niche under the screen...have two super quiet fans sucking air through the front the of nich's fabric doors, over the equipment, and up into the void behind the screen...works great...keeps it all very cool and is very quiet. Think a lot of people forget how important proper ventilation is. Both fans are connected to the Monster Power Center so only come on when the amp is on.

http://www.koberlinstudios.com/Home_Theater/110507/HomeTheater3.jpg
The Mitsubishi HD1500 projector. Love it...very bright, nice picture, affordable, and pretty darn quiet. AC runs back to the Monster Power Center. Mounting by Mount Direct...another inexpensive high quality solution. The PJ sits far enough back from the screen that I have some play on the zoom. Hangs down around 18" and is obviously flipped upside down to compensate for how far down the top of my screen is from the ceiling.

http://www.koberlinstudios.com/Home_Theater/110507/HomeTheater2.jpg
Food in hidef on an 80" screen...LOVE IT! At 80" diag this is the smallest screen The Screen Research company offers. Has their patented "CL2" woven fabric for acoustical transparency. The woven material method also minimzes the moire effect that a lot of perf screens can be prone to. This thing came up on Ebay for like $900 and JUST fit into the recessed wall I already had my plasma in...if you can get your hands on a SR screen then DO...beautiful picture with 100% acoustic transparency. Also comes in a satin frame finish which would have looked nice as well.

http://www.koberlinstudios.com/Home_Theater/110507/HomeTheater1.jpg
More food ( ;


Best of all this setup fit nicely into our family room, I definitely never liked the idea of having to go into a separate "theater" to watch TV...this is a nice comfortable situation...plus the kitchen is right out of view for easy access to movie grub! Just make sure to put up some heavy drapery as the ambient light can be a picture killer....oh yea...and don't play movie at 85db when your wife is trying to sleep upstairs.

http://www.koberlinstudios.com/Home_Theater/110507/HomeTheater7.jpg

^^^^ very nice and clean set up.

quick question on the calculators. i can select a PJ and then the screen size i desire to help determine the throw distance, correct? that way i can determine where to pre run my PJ wires during construction of my basement. thanks.

quick question on the calculators. i can select a PJ and then the screen size i desire to help determine the throw distance, correct? that way i can determine where to pre run my PJ wires during construction of my basement. thanks.

Yes, correct. I used Projector Central's calculator:

http://www.projectorcentral.com/projection-calculator-pro.cfm

Placed my PJ's zoom in the middle of the PJ's range, put in my screen size, and figured the distance I would need to have my wires run. This would leave available zoom either front of backwards to fill the screen appropriately. Figuring out how far the PJ needed to hang down was actually just as difficult. The PJ manual has that info.

If I could have done it all again, I would have:

- Run the PJ cables to the general location and left them behind the drywall, to be punched through when I actually had the PJ in my hands. This way you don't prematurely punch a hole through your drywall that may not workout once everything is mounted. Just take a pic of where the wires are prior to drywalling. Numbers on a calculator are one thing, actually having the PJ mounted and figuring out hand's on where exactly to place it is another.

- Also would have run one extra HDMI line as just recently my friends HDMI cable "went bad" in his PJ setup and he is having to figure out how to pull another new one without punching holes through his wall again! Also run a few CAT6 cables just in case.

You may also want to install a large piece of wood or two (maybe a 1" by 12" piece) in between your floor joists in the general vicinity where the PJ will be mounted so you can easily mount the PJ mount without having to be near a stud. Also make sure to run the 120 needed to power the PJ so that it can be tied into your other gear's power center.

^^^^ good info K.

not sure i can copy and past the link with my info in it but....LINK (http://www.projectorcentral.com/Sanyo-PLV-Z5-projection-calculator-pro.htm).

using this approach with a 106" screen i will be mounting at 14'. i plan to run conduit from the projector to my equipment rack for future proofing.

later.

I'm going through the same thing now. The projector has a massive offset. I'm going to have to end up mounting it upside down because if you put it anywhere near the ceiling, it's going to throw a picture on the ceiling itself. I guess if you can let it hang down some, it might work.....no idea how far. I'm going to try and eyeball it.

The projector is supposed to be upside down if you are ceiling mounting it. Or am I misunderstanding what you said?

Great looking install!

One question, though-- with your speakers behind the screen, why did you install your center channel horizontally instead of vertically? Is there any timbre change compared to the L&R as you move around the room?

not sure i can copy and past the link with my info in it but....LINK.

Looks like your FL reading at 14' is around 12 for your 106" diag screen. If your room is totally light controlled should not be a problem I would assume. At 15' the calculator recommends that you get a brighter projector so you are right on the edge. Maybe mount a little closer to be safe?

i plan to run conduit from the projector to my equipment rack for future proofing.

Great idea.

The projector is supposed to be upside down if you are ceiling mounting it. Or am I misunderstanding what you said?

You are correct.

Great looking install!

Thanks! It really is a long-time dream come true!

One question, though-- with your speakers behind the screen, why did you install your center channel horizontally instead of vertically? Is there any timbre change compared to the L&R as you move around the room?

M&K designed the center to be mounted horizontally. Think the only thing they did was angle the tweeter down a bit, flipped the speaker terminals on the back, and put the logo on differently. This line of M&K's was manufactured with their new "angled tweeter" idea...on the center and surrounds...as a result the surrounds are actually both different...one needing the be the left surround and one the right..so their respective tweeters are directed away from the listener (towards the outside of the room) to widen the sweet spot for the listener(s).

M&K designed the center to be mounted horizontally.

Ahh-- that makes sense. I figured there had to be a good reason.

Yes, smart guys over there at M&K (or what USED to be M&K...not sure what their status is anymore).

1) I ripped out the shelving in the media niche for a clean well-ventilated and easily accessible install. Removed old CD changer to open space and re-ran all cables.

2) Added a PS3 and an HDMI switcher from Monoprice. Blue Ray looks super clean and sounds amazing. Wonder what it would sound like if I was listening to the lossless audio tracks?? One day I will get a new receiver that decodes DD/DTS HD Audio however I still love my AVR5700 (http://www.amazon.com/Denon-AVR5700-Audio-Video-Receiver/dp/B00001R3VZ). Anyway the HD cable box and PS3 now switch through the HDMI switcher.

3) Added a great remote (http://www.universalremote.com/product_detail.php?model=102). Now everything runs off it. Programmed all the macros for one touch operation...all for only around $80! One thing I wish these remotes would all integrate is "power" sensing...to be able to tell if a unit is powered on or off...then they would be perfect.

4) Have also already added Cars, The Discovery Atlas Series and Discovery Planet Earth series to my Blu Ray collection.

Think I am all set (finally!)....might also add an external hard drive to my cable box to be able to get more HD recorded some day.