Can't get rectangular picture from projector

facehugger99

Hello,

So like the title says, no matter how much adjustments I make in the keystone settings on my projector the picture is always a bit 'trapazoidally'.

It's a ceiling mount btw - not sure if that's part of it.

Is there anything I can do about this?

The Ritz

Using keystone adjustment in a projector is always going to result in an imperfect picture - the projector is digitally distorting the image to try to approximate a rectangular shape. I'd recommend trying to position the projector/screen so that you don't have to use keystone - what projector are you using ? If you don't have the user manual for the pj try the web for a download - it will help you get the optimum picture in relation to the screen.

Cheers,

Ritz.

facehugger99

The Ritz wrote: »

- what projector are you using ? If you don't have the user manual for the pj try the web for a download - it will help you get the optimum picture in relation to the screen.

Cheers,

Ritz.

It's a JVC D-ILA.

I have tried moving the projector before, but I guess I'll turn off keystone and give that another go - there's not a huge amount of 'play' in the movement of the projector whatever way I have it mounted.

The screen is fixed so can't really move that.


Thanks.

facehugger99

OK, turned off keystone and I've had a go at trying to move the projector, but the issue I'm having is that, while I can move it left and right, I can't really move it up/down - well I can but it just returns to the original position. It just hangs out of the ceiling mount at a particular angle - I think that's what's casing the trapezoidal image.

Do most ceiling mounts allow you to adjust the angle of the projector? I don't want to go adjusting screws in case they are the things attaching the projector to the mount.

The Ritz

You should be able to adjust the angle of the projector at the mount - in fact the projector should be mounted completely level and at a height in relation to the screen that facilitates a correctly oriented image. It sounds as though the projector hasn’t been mounted properly - without seeing it I can’t really say. Did you install it ( I assume not from your replies above ?) if not you should get in touch with whoever did the installation and get them to assist ? If you can post a couple of pics of the mount and some info about the position of the projector and screen respective positions, it could help.


Also, where are you located ? Answer by PM if you want to keep that out of the reply here.


Ritz.

facehugger99

Unfortunately installed it myself, can’t blame anyone else.

It’s up a few years now, just got used to the slightly off image.

The projector is definitely pointing downwards, it’s not level.

I can’t really remember which screws on the mount are for attaching and which are for adjusting.

I’ll post up a couple of pictures tomorrow.

Thanks for the assistance.

The Ritz

No problem. When a projector tends to point down on its mount it suggests that the centre point of the mount is located behind the centre of gravity of the projector - this makes the projector “front heavy”, if that makes sense, and causes problems.

Cheers,

Ritz.

facehugger99

Hope these pictures are ok to show the issue.

endacl

Your Star Wars pictures are a bit wonky too!

facehugger99

endacl wrote: »

Your Star Wars pictures are a bit wonky too!

I've asked for a spirt level for my birthday this year.

The Ritz

Hi,

Looks like your projector is positioned incorrectly on the mount - from the pictures it is "front heavy" as I mentioned earlier, it looks like the circular plate of the mount is distorted by the weight of the projector and it also looks as though the front part of the plate screwed to the ceiling is being pulled down too. I think that you'd have to take the projector down and try to reposition it at the least. This is assuming that the mount is strong enough for the projector, I don't recognise the make of the mount from the pictures.

Whats the model number of the projector ? if you check the manual it usually shows the recommended position of a ceiling mount, it might help you get sorted.


Ritz.

slave1

Never seen a projector mounted at that extreme an angle, the projector should be level and then use lens shift functionality on the menu settings to move the projected image downwards.
You will never get that projector to exactly hit the edges of the screen, in any case that is a very difficult task even with a perfectly mounted projector and screen.

The image below gives you an idea...

facehugger99

OK - grand, will have a look at the mount and see if I can get it to hang more level.

It's strange, because from looking at it again, the slant seems to be more a result of the position of the fixing points on the projector as opposed to an issue with the mount - as you say, the projector seems front-heavy - there doesn't seem to be anything on the mount to adjust to compensate for this though.

Appreciate the advice.

The Ritz

there doesn't seem to be anything on the mount to adjust to compensate for this though.

This view of a very similar (the same?) projector mount might explain:



The screws connecting the arms to the circular mounting plate run in arc shaped slots - by moving the relative position of the arms it is possible to alter the front/back/side-to-side position of the mounting point of the projector.

It is possible that the dome shaped part of the mounting plate has a slot in it that allows the mounting plate and arms to be mounted at an angle - the plate may have tilted under the weight of the projector or may have been fixed that way originally - this is visible in your picture ending in 111823.jpg.

I'm also pretty sure that the screw on the side of the shaft of the mount above the black plastic ring (shown in the same picture mentioned above) connects the mounting plate to the shaft - there is a metal piece that goes up inside the shaft and the screw locks it in place.

One way or another, the solution here is to dismount the projector and resolve the issues with the mounting plate - taking it down is really a two man job - because of the design of the mount offering it back into place while attempting to replace the locking screw would be pretty difficult. Taking it down is less so, as long as you have the weight of the projector securely managed before releasing it from the mount.

Helpful hint ? Make a temporary handle for the projector with webbing straps or similar - this will enable you (or your helper) to hold/lift the projector far more securely than trying to do it with two hands, although you'll probably have to get it into position by hand at the end.

If this is unclear, feel free to PM me to discuss offline if you like.

Good luck, its a super projector and you deserve to get the best out of it.

Cheers,

Ritz.

facehugger99

The Ritz wrote: »

The screws connecting the arms to the circular mounting plate run in arc shaped slots - by moving the relative position of the arms it is possible to alter the front/back/side-to-side position of the mounting point of the projector.

Ah! - yep, can see how that might do the trick.

The Ritz wrote: »

I'm also pretty sure that the screw on the side of the shaft of the mount above the black plastic ring (shown in the same picture mentioned above) connects the mounting plate to the shaft - there is a metal piece that goes up inside the shaft and the screw locks it in place.

At the risk of asking another dumb question - so can I just unscrew this screw to take it down as opposed to taking the whole mount off the ceiling?

The Ritz

At the risk of asking another dumb question - so can I just unscrew this screw to take it down as opposed to taking the whole mount off the ceiling?

I reckon so, yes, I can't see any other way of dismantling it - it would be very unusual to have to take it off the ceiling altogether, I never came across something like that but I'd be making double sure that I had the projector securely supported before undoing the screw in question ! !

Ritz.

facehugger99

No more trapezoid.

Cheers.

The Ritz

Happy days !

What was the problem, curious to know ?

Ritz.

facehugger99

The Ritz wrote: »

Happy days !

What was the problem, curious to know ?

Ritz.

Just followed your advice.

Took it down (carefully), adjusted circular plate and mounting arms to level projector.

Re-attached it to the mount.

Did a bit of manual adjustment then used the shift to get the picture right.

Haven't used keystone at all and have a (almost) perfectly rectangular picture.

So - issue was obviously the original mounting angle.

The Ritz

Glad you got it fixed, it’s a super projector and well worth the effort to get it at its best.

Cheers,


Ritz.