can't square picture on screen

stegalv

Member
i have a mitsubushi 16500 projector,i have tried all of the adjustements,but can't get the picture square on the screen.

screen-1.jpg

i just can't figure it out,so i am asking if anyone has an answer,it could be something simple that i am missing and is staring me in the face.
the projector is about 9 to 10" to the right of vertical centre and slightly above horizontal center of the screen.
the weird part is if you look at the photo it is more or less square along the top border,and down the left and right black borders,the only place it is running way out is along the bottom border,running up from the left corner to the right corner? but not along the top left to right.
i can't see what adjustment would only bring the bottom right down,
 

nwgarratt

Member
How is the pj positioned. If it is on shelf or something similar then just lift the pj at the side to lower the opposite side. It may then have to lifted at teh back so the image lowers to the bottom of the screen. I have had to the same thing as I have a uneven floor. If it is ceiling mount could it be tilted?
 

stegalv

Member
thanks for the replys.it is ceiling mounted,but if i tilt the pj it moves in two planes not just the bottom corner i:e if i tillt the pj down to the right to bring it level horizontally across the bottom then the top right drops making the picture run down from top left to top right. also the left hand side of the picture runs out vertically from top left to bottom right?
 
have you checked the pj and screen fitting with a spirit level, along both axis. also measure distances. is the screen it self symmetrical? measure that as well.
 

Danny1980

Active Member
I'm not familiar with the Mitsubishi PJ, but if it's anything like the Optoma HD65 it can be a headache getting the PJ positioned correctly in relation to the screen.

From the picture it looks like the PJ is offset to one side and not square onto the screen.

I'd would say the PJ/mount wants moving over to the left slightly.
 

jacko5

Active Member
Does your PJ have vertical and horizontal lens shift? If it does, forget about the screen for a moment. Twist and tilt the projector until, by trial and error you have a perfect rectangle. Use a measure to confirm you have a perfect rectangle. The image is now probably much too high, or low and way off centre of the screen. Now, using only the vertical and horizontal lens shifts, bring the image to fit the screen.
 

xavier71

Active Member
had pretty much the same issue as you have (got an hc6500 myself,excellent pj),had an optoma hd80 before this pj and when i swapped it i fitted it back where the hd80 was and had a similar problem to you.

Ended up moving it about 8" to the left and now it fits as snug as a bug in a rug, and i mean perfect, i actually used an extension bar on my ceiling mount to drop it 8" also but i wouldnt of thought you would need that, my ceiling height in my loft extension is only 2m and the extra drop lines it up perfectly for me.

I will say though that moving it 8" to the left of my original position puts the pj perpendicular(i think thats what you call it, and how you spell it)to my screen, which is always a good thing.

Good look let us know how you get on.
 

binbag

Active Member
From the picture it looks like the PJ is offset to one side and not square onto the screen.

I'd would say the PJ/mount wants moving over to the left slightly.

I'd agree with the above.
 

Peter Parker

Distinguished Member
I also agre with Danny.

If the pj is slightly to the right of center, the lens is closer to the right hand side of the screen than the left side so the image is smaller on the right side than the left side (it doesn't have to be out by much to get the effetc your seeing). If you move the pj to the left and rotate it to the right to center the image on the screen, it should be square.

Gary
 

nwgarratt

Member
I also agre with Danny.

If the pj is slightly to the right of center, the lens is closer to the right hand side of the screen than the left side so the image is smaller on the right side than the left side (it doesn't have to be out by much to get the effetc your seeing). If you move the pj to the left and rotate it to the right to center the image on the screen, it should be square.

Gary

That makes sense.
 

stegalv

Member
thanks everyone for your help,it seems the problem is that the projector is right of centre,i thought the adjustments would have dealt with this problem,but i was wrong.
sorry gary but what do you mean by rotate the pj.
again thanks everyone
 

Danny1980

Active Member
thanks everyone for your help,it seems the problem is that the projector is right of centre,i thought the adjustments would have dealt with this problem,but i was wrong.
sorry gary but what do you mean by rotate the pj.
again thanks everyone
I hope Gary doesn't mind me answering.

At the moment the lens is off centre, therefore the PJ is twisted, it's not square onto the screen.

If you rotate the PJ to the right you will notice the boarder you have at the bottom straighten up, you will also notice the sides don't fit on screen, you will have a boarder on the left and the right hand side will be off screen - this is how you want the PJ to finally sit, now you have to move the PJ/mount over to the left so the sides fit perfectly.

If you just moved the PJ/mount over without rotating the PJ the sides would be off screen. You would end up with a boarder on the right with the left hand side off screen.

I hope that makes sense.

Alternatively, slide the screen over to the right, this of course depends on installation/fittings etc.
 
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stegalv

Member
thanks danny,but i thought the lens shift would compensate for the off centre pj
 
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LV426

Administrator
Staff member
Yes, just to re-iterate. First, twist (rotate) the projector horizontally (front/lens to the left, by the look of it) until the top and bottom edges of the image are straight and parallel - ignore whether the image is on the screen at this point. Then use the horizontal lens shift adjustment (assuming it has one) until the image sits properly on the screen. Do it in stages/by trial and error, if necessary.
 

Danny1980

Active Member
thanks danny,but i thought the lens shift would compensate for the off centre pj
Lens shift just moves the image that's projected, it doesn't adjust the image in any way.

You are going to have to Rotate the PJ to right first and straighten up the image before you use the lens shift.

If the PJ hasn't got lens shift you might be able to use H shift, that's if it has enough adjustment. Otherwise it will be a case of moving the mount/PJ over.
 

Chox1988

Distinguished Member
I think you want keystone correction not lens shift to actuallly adapt instead of move an off centre picture
 

Danny1980

Active Member
I think you want keystone correction not lens shift to actuallly adapt instead of move an off centre picture
Unless the PJ has horizontal keystone correction (I don't know any that do, only vertical) I can't see how they are going to straighten up the image other than rotaing the PJ, then using either lens shift of V/H shift or phiscally moving the mount/PJ.

Would advise againts using any form of keystone correction as this will degrade the image, compression is used to correct the trapezoid effect.
 

jacko5

Active Member
jacko,i did try what you suggested,but the lens shift would'nt bring it back enough.thanks
In which case I am afraid you will have to move your projector mount in the approriate direction to bring it nearer to the vertical centre of the screen.
 

LV426

Administrator
Staff member
Well, you need to do one or other of two things:

1: Rotate the positioning of the screen to bring the right hand side closer to the projector - enough to bring it within the lens shift adjustment. Or
2: Alter the positioning of the projector to the right - enough to bring it within the lens shift adjustment.

(or live with it!)



Edit: what he said ^^^^
 

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