first of all I'd like to say hi to everyone since this is my first post here.
very imformative forum!

of course i did a search but didnt get a similar thread in the results.

what i wanna ask is if it is safe to simply position my BenQ PB7220 (or any other model or make) perpendicular to the floor (quite possibly using a custom mount) and watch stuff on the ceiling while laying down in bed.

i guess you need some explaining.. in a few words, my father suffers from a very bad back and has to lay in bed for many hours. he used an old sony projector that could be tilted an any angle from 0 to 90, with great success for many years.
so now we are thinking the same thing can be done with the newer and much better BenQ.. but since we are hardly experts we're wondering if such positioning will damage the projector, in any way shape or form.
AFAIK, there is no warning against this by the manufacturer.

ANY help would be greatly appreciated. i apologise if this has been discussed before, but all i found were ceiling mount threads.

thanks, babas.

Most modern front projectors advise against positioning them this way. Have you considered using a "desktop" orientation and bouncing the image off a small, high-optical-quality mirror? Try this website, for example: http://www.fsmirrors.com/

As suggested most manufacturer indicate that this isn't a good idea (ie. having a projector pointing up or down for that matter). However, its kind of "funny"... since they don't seem to mind turning it upside down... :-) Anyways, I think that the reason for the "recommendation" is that you change the air flow especially if the projector flows air out the back.... pointing this up may cause a significant cooling issue. In addition, the color wheel orientation might be an issue. Having said that, a projector like an infocus X1 has air flow out the front of the projector and the color wheel orientation is such that upside down, right side up and pointing up or down keep the wheel in the same "spin plane".

The suggestion about "bouncing" is a good one. Having said that, in the past (distant) there have been posts about people mounting a projector vertically behind a furniture piece (chair / table / couch) and using a mirror to direct the beam horizontally towards a wall mounted screen. I don't believe that they posted their results or whether they had any "ill effects".

The projector has to stay fairly level to cool properly. Just about any mirror will work pretty well. About 6 months ago we tried an experiment to do just this thing and used the mirror from a medicine cabinet for the experiment and it worked quite well. The fear some have with using a back silvered mirror is that you will get an offset ghost image off the first glass surface, and then the real reflection will come off the silver in the back. We didn’t see this happening YMMV. If you do a second surface mirror pick a cheap thin one to try first. if you get a optical quality mirror (first surface) you may want to try a TV shop and see if they have one out of a junk RPTV.

The reason we did it was to do a very large screen size in an area that didn’t have enough throw length but the ceiling would be the same idea.

Good luck and please post back with what you find and pictures are always great.

PS you will have to flip the image in the projectors menu to get it to come out correct after bouncing off the mirror.
:)

hey thanks for the quick replies..

i figured something might go wrong with cooling.. now i'm too afraid to even try this.
have no idea where i can find a good mirror locally and will probably not risk having a mirror shipped overseas. but i will look into it, i never thought about this to be honest!

i will certainly update if we decide on any course of action.

btw, is anybody aware of projectors in the market that are intended for such use?
our old one is the sony cpj-200. i remember it was dirt cheap many years ago (even though it goes for $600 on ebay these days) and my father was never really big on picture quality.
a current equivalent would be perfect for the job at hand!

babas.