AVS Forum banner
1 - 15 of 15 Posts

·
Premium Member
Joined
·
5,457 Posts
Discussion Starter · #1 ·
Leaving out the pros and cons of constant width vs constant height I am wondering if the following set-up is possible with any current 1080P projectors:


Setting up the projector for 2.35:1 (say 54 x 127) with an anamorphic lens in place, and proper video processor, and adjusting the proper zoom and focus setting into memory 1 of the projector.


Remove the anamorphic lens and keeping the same throw distance adjust zoom and focus for 16:9 screen 72 x127 and setting into memory 2 of projector.



Could the above be done to automate a constant width setup on a screen 72 X 127 with masking ?
 

·
Registered
Joined
·
8,958 Posts
With or without the lens, letter boxing of a scope image is constant width. The lens benefits you by allowing you to 100% of the panel for "scope" rather than the 75% used when projecting letterboxing.


What your trying to achieve should work so long as the "scaling" is not forgotten...


Mark
 

·
Registered
Joined
·
8,958 Posts
Yes you also have to use a VC lens as well. So how are you going to perform the scaling?


Mark
 

·
Premium Member
Joined
·
5,457 Posts
Discussion Starter · #5 ·
Totally confusing on my part, let me try and clarify


Is it possible to set the projector up with an anamorphic lens and scaler for 2.35 at 54x127 and also set if from the same throw distance, remove the anamorhic lens and adjust via Zoom and other projector adjustements to 72x127 image?


In other words 2 independent settings from the same throw distance:

1) anamorphic lens in place scaling a 54x127 image

2) no anamorhic lens and a 72x127 image


Is the above possible?
 

·
Registered
Joined
·
8,958 Posts
Yes by using a VC lens not a HE lens. The VC lens's "scope" image is set by the width and vertically compresses the height, so you can achieve exactly your posted dimensions.


Your throw will not change, just the image height at the 16:9 beam will be reduced to 67% of the height when it is in place...


Mark
 

·
Registered
Joined
·
8,958 Posts
HE stands for Horizontal Expansion and is used for CIH. You need a Vertical Compression lens to do CIW...


Mark
 

·
Premium Member
Joined
·
5,457 Posts
Discussion Starter · #9 ·
Mark:

Thanks again so to do constant width with a 72 x127 16:9 screen I would move a Vertcal Compression lens in place and scale for 2:35 Scope 54x127, and by simply removing the lens from the equation I would have full resolution 16:9 @ 72x127, with no zooming nor scaling required ?.


I understand this is the Constant Image Height forum, is it possible to have a sub forum for the few who are interested in discussing Constant Width or Constant Area?
 

·
Registered
Joined
·
8,958 Posts

Quote:
Originally Posted by LJG /forum/post/0


Mark:

Thanks again so to do constant width with a 72 x127 16:9 screen I would move a Vertcal Compression lens in place and scale for 2:35 Scope 54x127, and by simply removing the lens from the equation I would have full resolution 16:9 @ 72x127, with no zooming nor scaling required ?.

You still need scaling, but no zooming is required for what you want to do. You simply remove the lens for 16:9...

Quote:
I understand this is the Constant Image Height forum, is it possible to have a sub forum for the few who are interested in discussing Constant Width or Constant Area?

You need to email Alan with that one...


Mark
 

·
Premium Member
Joined
·
5,457 Posts
Discussion Starter · #11 ·

Quote:
Originally Posted by CAVX /forum/post/0


You still need scaling, but no zooming is required for what you want to do. You simply remove the lens for 16:9...


Mark

This is where I am lost why would I need to scale a 16:9 Image for a 16:9 projector on a 16:9 screen?


Lon
 

·
Registered
Joined
·
8,958 Posts
You don't, but you need to scale for "scope" when you move the lens in place or the image will look "short and fat" with a VC lens...


Mark
 

·
Registered
Joined
·
8,958 Posts

Quote:
Originally Posted by LJG /forum/post/0


Correct I think I got it, with VC lens in place scale for scope, with VC lens removed 16:9 without scaling or zooming!!

Your've got it...


Mark
 

·
Registered
Joined
·
334 Posts
This is what I have.


I have a vertical compression anamorphic lens in front of my Optoma HD70 PJ on a hinge.

When I want to watch 2.35:1 movies, I just pop the anamorphic lens in place, select the LBX mode on the PJ which vertically stretches the image which removes the black top and bottom borders and the lens vertically squeezes the image to the correct aspect ratio.


When I want to watch standard 16:9 movies, I just unhinge my anamorphic lens, select 16:9 mode on the PJ and i've done.


Hope this helps.
 
1 - 15 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top