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Discussion Starter #1
How much overscan is acceptable when zooming to 2.35:1 format?

I guess something must be wrong when you have about 2.5 inches left on both the left & right sides at your scope screen. Top and bottom are perfectly right zoomed in but the sides are not enough to fill.

Is the movies aspectsratios not 100% correct?


Any thoughts on what exactly causes this?
 

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It might just be the specific ratio of the source material (many things vary slightly). It might also just be the difference between 2.35:1 (which is how most scope screens are built) and 2.37:1 (which is the mathematical 1.33 expansion of 16x9 (1.78:1) material. When I first hoisted my lens into position to test for the first time I saw much the same thing... have gotted used to the notion now.
 

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Discussion Starter #4

Quote:
Originally Posted by GKevinK /forum/post/12966662


It might just be the specific ratio of the source material (many things vary slightly). It might also just be the difference between 2.35:1 (which is how most scope screens are built) and 2.37:1 (which is the mathematical 1.33 expansion of 16x9 (1.78:1) material. When I first hoisted my lens into position to test for the first time I saw much the same thing... have gotted used to the notion now.


I tested different source material with 2.40:1 and 2.35:1 "Transporter" on BD and "Shooter" both are supposed to be 2.35:1 in aspectsratio.


My screen is 125" Diagonal.. so i thought 2.5 inches on EACH sides are waaay too much since the source is supposed to be 2.35:1.??


How would then a A-scopelens cut the sourcematerial exactly? Is truly using all 100% in the picture, without cropping off % of picture information?


If not then all movies would are different in aspect ratio from the cinemascope standard AR.
 

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Discussion Starter #5

Quote:
Originally Posted by GKevinK /forum/post/12966662


It might just be the specific ratio of the source material (many things vary slightly). It might also just be the difference between 2.35:1 (which is how most scope screens are built) and 2.37:1 (which is the mathematical 1.33 expansion of 16x9 (1.78:1) material. When I first hoisted my lens into position to test for the first time I saw much the same thing... have gotted used to the notion now.
Quote:
Originally Posted by Art Sonneborn /forum/post/12967055


WSR used to measure the AR on the discs I don't know if they still do or not.


They varied quite a bit but 2.5" is a lot unless it is a very large screen.



Art

Thats what i thought as well. 2.5 is pretty much what is missing at each side.


It can't be the PJ or the BD&HD player...Or the screen AR since it's a 2.35:1...
 

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What projector do you have, and have you turned off any "overscan" settings or other image controls that might be affecting the source image? It sounds like you have some overscan control active on the PJ or there is overscan/pixel cropping in the source. On a 16x9 image, overscan crops the image equally on all sides, giving you the same AR after the overscan is applied. On a scope image, the displayed AR actually changes because only the sides of the image are cropped, the top/bottom are black bars.


Try this - disconnect your projector from the source or just switch to an unused input on the PJ - what do you see - does it look correct?
 

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Discussion Starter #7

Quote:
Originally Posted by usualsuspects /forum/post/12968922


What projector do you have, and have you turned off any "overscan" settings or other image controls that might be affecting the source image? It sounds like you have some overscan control active on the PJ or there is overscan/pixel cropping in the source. On a 16x9 image, overscan crops the image equally on all sides, giving you the same AR after the overscan is applied. On a scope image, the displayed AR actually changes because only the sides of the image are cropped, the top/bottom are black bars.


Try this - disconnect your projector from the source or just switch to an unused input on the PJ - what do you see - does it look correct?

There is no option for overscam sorry overscan on the hdmi inputs on the Sony HS-60
it's pretty crappy in that regard.


I don't know maybe it supposed to be like that..missing picture information on 2.35:1 AR maybe call it 2.20:1?
 

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Discussion Starter #9

Quote:
Originally Posted by usualsuspects /forum/post/12969423


According to this cine4home review:
http://www.cine4home.com/reviews/pro...HS60Review.htm


720P HDMI input is the only resolution that is free from overscan.

Well if that is true how come 1.85:1 movies are cropped to 1.78:1 ?

i,ve never seen any thin black bars nor at the top or bottom. Or is that too small of a difference to notice?


I tried with HDMI input and switched to different inputs on both the PJ itself as the BD and HD DVD players. The outcome is the same, it fills the top and bottom of the screen but still missing 60mm 2.5" at L&R sides at the screen.


From what i've seen listed on theatrical AR of scope movies the differences is never this dramatic as i seem to experience.


2.5" at L&R edges at a screen size of 125" what AR would that be to be exact?

Any more clues to what could cause this big missing picture information at the side edges?


Thanks
 

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Quote:
Originally Posted by radical68 /forum/post/12975723


Well if that is true how come 1.85:1 movies are cropped to 1.78:1 ?

i,ve never seen any thin black bars nor at the top or bottom. Or is that too small of a difference to notice?

That is exactly what you would expect to see with significant overscan. 1.85:1 has small black bars top/bottom - the overscan is chopping off the black bars and some of the image top/bottom and chopping off some of the image left/right - you end up with a 1.78:1 image the fills the entire panel.

Quote:
I tried with HDMI input and switched to different inputs on both the PJ itself as the BD and HD DVD players. The outcome is the same, it fills the top and bottom of the screen but still missing 60mm 2.5" at L&R sides at the screen.


From what i've seen listed on theatrical AR of scope movies the differences is never this dramatic as i seem to experience.


2.5" at L&R edges at a screen size of 125" what AR would that be to be exact?

Any more clues to what could cause this big missing picture information at the side edges?


Thanks

What does overscan do? It essentially magnifies/scales the input image to be larger than it should be, then anything outside the native panel area is lost.


What happens for different AR's when there is significant overscan:

Input AR / Output AR:

1.78:1 / 1.78:1 - image area is lost on all sides

1.85:1 / 1.78:1 - image area is lost on all sides , but with more lost on the left and right - black bars are completely swallowed.

2.35:1 / ?????? - image area is lost on left/right - none is lost top/bottom that you can see, because that area is black bars. The displayed AR ends up being less than 2.35:1, how much less depends on the exact amount of overscan. This makes the scope image "taller" and the "width less" (actually the width is the same with image lost on the left/right, but that is the effect seen).


Your projector is known to have significant overscan when sent any resolution signal other than 720P over HDMI. Go into the setup menus on your sources and change the output resolution to 720p. This problem should disappear.
 

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Discussion Starter #11

Quote:
Originally Posted by usualsuspects /forum/post/12976639


That is exactly what you would expect to see with significant overscan. 1.85:1 has small black bars top/bottom - the overscan is chopping off the black bars and some of the image top/bottom and chopping off some of the image left/right - you end up with a 1.78:1 image the fills the entire panel.




What does overscan do? It essentially magnifies/scales the input image to be larger than it should be, then anything outside the native panel area is lost.


What happens for different AR's when there is significant overscan:

Input AR / Output AR:

1.78:1 / 1.78:1 - image area is lost on all sides

1.85:1 / 1.78:1 - image area is lost on all sides , but with more lost on the left and right - black bars are completely swallowed.

2.35:1 / ?????? - image area is lost on left/right - none is lost top/bottom that you can see, because that area is black bars. The displayed AR ends up being less than 2.35:1, how much less depends on the exact amount of overscan. This makes the scope image "taller" and the "width less" (actually the width is the same with image lost on the left/right, but that is the effect seen).


Your projector is known to have significant overscan when sent any resolution signal other than 720P over HDMI. Go into the setup menus on your sources and change the output resolution to 720p. This problem should disappear.

Ok i'll try..but i have tried finding the menys to change the setting to 720P without succes. Do you have to go to the factorysetup? or how exacly can i change it?


Thanks Usualsuspects
 

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I assume you are using HDMI inputs, otherwise it might not make any difference. It was not clear to me from that review if this problem affects component/other inputs. The resolution needs to be changed on the source devices. On HD-DVD players - you press "setup" - then go into resolution and change it to 720p. Different sources will have different steps and menus.
 

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Have you tried to increase the zoom to fill the 2.5" of blank screen on each side? If so how much of the picture spills over the top and bottom of the screen? I am not zooming but with my lens I have less then 1/2" of spill or overscan (even though it is not technically overscan) all the way around my screen.


Are you sure the screen is 2.35:1. Have you measured the height vs. the width and calculated the actual ratio of the screen. They may have manufactured it incorrectly.


Laters,

Jeff
 

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Discussion Starter #14

Quote:
Originally Posted by usualsuspects /forum/post/12989028


I assume you are using HDMI inputs, otherwise it might not make any difference. It was not clear to me from that review if this problem affects component/other inputs. The resolution needs to be changed on the source devices. On HD-DVD players - you press "setup" - then go into resolution and change it to 720p. Different sources will have different steps and menus.

Problem solved. Thanks for the help. This PJ is very bad at overscan just one input that has the ability to handle the right format without overscan. Now i can watch TRUE cinemascope..... WOW never more 1.78:1... Hope my new Sony Black pearl will be a good one for CIH.


Thanks again Usual suspects
 

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Quote:
Originally Posted by radical68 /forum/post/12999709


Problem solved. Thanks for the help. This PJ is very bad at overscan just one input that has the ability to handle the right format without overscan. Now i can watch TRUE cinemascope..... WOW never more 1.78:1... Hope my new Sony Black pearl will be a good one for CIH.


Thanks again Usual suspects

Glad to help. I have the Black Pearl, I think you will be happy with it
The BP has an overscan setting in the projector menu, can't recall if it was on or off from the factory.
 

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Discussion Starter #16

Quote:
Originally Posted by usualsuspects /forum/post/12999843


Glad to help. I have the Black Pearl, I think you will be happy with it
The BP has an overscan setting in the projector menu, can't recall if it was on or off from the factory.

Alright, then you'll have to give me some good tuning tips for the BP later on
 
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