"bending" image

bigshot1970

Novice Member
hi,
first post and I'm not very technical so you'll have to bear with me a bit. hopefully someone can help.
I've got an LG home theatre system and an optima projector. they're both pretty old and (for various reasons) have been in storage for a number of years.

If I play a movie through the projector and it's ratio a particularly wide and narrow aspect ratio - like 2.35:1, the image tends to "bend" at the left and right sides. it's particularly noticeable if the camera is panning across in the movie and objects and people stretch and narrow slightly.

I'm projecting on a white wall btw, not that it should make any difference.

is there a setting adjustment I can make on the player or the projector to stop this from happening?

thanks in advance!
 

Spigot

Active Member
If the wall is flat and the projector is perfectly perpendicular to the wall then perhaps digital keystone correction is not set to zero in the display menu. Conversely, if the projector isn't correctly aligned with respect to the wall then enabling keystone correction could fix the distortion.
 

ShanePJ

Well-known Member
AVForums Sponsor
When you say it only happens when watching ultra-widescreen movies, you mean that the black bar looks to be bent? Is this the same when watching a traditional widescreen 16/9 film?

I does sound like it should be the wall at fault. If you've got a flat meter rule, this would answer that question better than us guessing.

If it bothers you, keystone may help, but do be aware that this will digitally alter the entire image and reduce the quality of it (it could change the throw distance to), so see if the drop off of the image is better or worse trade off when using keystone.

In order to see if the projector is out perpendicular to the, where the image drops off, try turning/twisting the projector in that direction by a very small fraction to see if it changes. If you find its moved to another corner, it doesn't do anything, it could be the lens or chip itself
 

bigshot1970

Novice Member
If the wall is flat and the projector is perfectly perpendicular to the wall then perhaps digital keystone correction is not set to zero in the display menu. Conversely, if the projector isn't correctly aligned with respect to the wall then enabling keystone correction could fix the distortion.
thanks Spigot, I don't think it is that
 

bigshot1970

Novice Member
When you say it only happens when watching ultra-widescreen movies, you mean that the black bar looks to be bent? Is this the same when watching a traditional widescreen 16/9 film?

I does sound like it should be the wall at fault. If you've got a flat meter rule, this would answer that question better than us guessing.

If it bothers you, keystone may help, but do be aware that this will digitally alter the entire image and reduce the quality of it (it could change the throw distance to), so see if the drop off of the image is better or worse trade off when using keystone.

In order to see if the projector is out perpendicular to the, where the image drops off, try turning/twisting the projector in that direction by a very small fraction to see if it changes. If you find its moved to another corner, it doesn't do anything, it could be the lens or chip itself
hi, no its not the black bar being bent. it's only really apparent when the camera pans across a very wide shot from left to right, or right to left. everything on the age stretches and then narrows as it moves across the screen. its looks as if you are projecting onto something which is be ding away at the edges. I'm struggling to think of a good example here - if you imagine you had a large tyre with no tread and it was sat on its side and you projected onto that. the parts on the left and right side would look as if they are bending backwards. this happens when the camera pans

the wall I project on is flat and the projector is parallel to the wall correctly as well

it might well be the distance and the size of the screen. currently the image is 11ft diagonal from corner to corner approx. and the distance between the lens and the wall is about 8ft.
I might try and make the image smaller (I haven't got anywhere else to move the projector backwards and I can't move there wall!) - then see if that makes a difference.

I'm quite limited with the room size/shape in the house and it's a rental so I can't change anything.
Mostly it's not really an issue but just occasionally on something like the Criterion edition of La Dolce Vita it can be a bit distracting

thanks for your help
 

Spigot

Active Member
Try maximum and minimum zoom to see if the distortion persists. If it does then it's not the wall. If it's a problem with the lens then maybe zooming in a small amount would mask the problem.
 
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noiseboy72

Distinguished Member
It sounds like there's an anamorphic setting, so that the edges of the image is being stretched or compressed. It may be that the projector is fitted with an anamorphic lens, but is not set correctly for it - or vice versa.

Some older TVs did this with 4:3 footage to stretch it to 16:9, but that was many years ago.

Check that the input and output resolutions are the same - so 16:9 in and 16:9 out and no stretch or zoom processing applied.
 

ShanePJ

Well-known Member
AVForums Sponsor
If you have a mobile phone, maybe try to capture a few seconds of video of the effects so we can all gain an idea as a picture usually says more than words :)
 

ask4me2

Active Member
In addition to capturing a video of the projected picture,
It may also be a good idea to reveal what optima projector this is too.
Then it will be easier to figure out if there are some lens, zoom, squeeze or stretch settings that may cause these problems.
 

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