16:9 Screen Vs. 2.37:1 CIH Screen - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #1 of 96 Old 01-22-08, 09:49 PM Thread Starter
HTS Senior Moderator
 
Prof.'s Avatar
The Mad Professor
 
Join Date: Oct 2006
Location: Murraylands South Aust
Posts: 8,367
My System
16:9 Screen Vs. 2.37:1 CIH Screen

These drawings show how the two different systems work, when it comes to screen size, image size, and aspect ratio..

The first one is for 2.35:1 DVD's..


Prof..
Home Theatre...the never ending story!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Prof. is offline  
Sponsored Links
Advertisement
 
post #2 of 96 Old 01-22-08, 09:50 PM Thread Starter
HTS Senior Moderator
 
Prof.'s Avatar
The Mad Professor
 
Join Date: Oct 2006
Location: Murraylands South Aust
Posts: 8,367
My System
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

This is for 1.85:1 DVD's..


When a 1.85:1 image is vertically stretched, you do lose a bit of the image top and bottom..
Some people prefer to use what's called the "Pass through mode"..That just means that the light path is no longer through the anamorphic lens..
So the corect AR is maintained..

Prof..
Home Theatre...the never ending story!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Prof. is offline  
post #3 of 96 Old 01-22-08, 09:50 PM Thread Starter
HTS Senior Moderator
 
Prof.'s Avatar
The Mad Professor
 
Join Date: Oct 2006
Location: Murraylands South Aust
Posts: 8,367
My System
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

And this is 1.78:1 DVD's..



As you can see for this AR, the Scope screen will have black bars at the sides..These bars can be simply masked, or as some people do, just leave them as they are..

Prof..
Home Theatre...the never ending story!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Prof. is offline  
 
post #4 of 96 Old 01-22-08, 10:18 PM Thread Starter
HTS Senior Moderator
 
Prof.'s Avatar
The Mad Professor
 
Join Date: Oct 2006
Location: Murraylands South Aust
Posts: 8,367
My System
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Reserved 3

Prof..
Home Theatre...the never ending story!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Prof. is offline  
post #5 of 96 Old 02-01-08, 12:03 AM Thread Starter
HTS Senior Moderator
 
Prof.'s Avatar
The Mad Professor
 
Join Date: Oct 2006
Location: Murraylands South Aust
Posts: 8,367
My System
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Here are some screenshots showing the various stages of converting your standard 2.35:1 DVD image to a full cinemascope image.
The camera hasn't picked up the blank part of the screen in the first two sequences, but you can see how the image changes..

All the pics were taken from the same position with the camera mounted on a tripod, and all at the same zoom setting..

The first shot in each sequence shows the normal image without any zoom on the projector..and without the anamorphic lens in place.


Now the images are vertically stretched by the projector or DVD player to the full height of the screen.

.
And finally the lens is in place, optically stretching the image to the full width of the screen, and restoring the correct geometry.













Prof..
Home Theatre...the never ending story!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Prof. is offline  
post #6 of 96 Old 02-01-08, 10:57 PM
Mark Techer
 
Join Date: Jan 2008
Location: Brisbane, Australia
Posts: 613
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Well done Prof, they are very CIH demo shots.

The best description I ever got was from the RUNCO guys at CEDIA. They did their speil as if no-one else had it, and they made simple.
They said CIH is two parts - Sclaing + Optics.

I guess the most difficult part is understanding the scaling aspect of the process. This is the electrical manipulation of the signal to -
A. rid the black bars and
B. use the full panel for max rez and image brightness.

Optics are a science all by themselves, and the part that makes understanding the difference between an anamorphic lens and conventional zoom lens is that the anamorphic lens only magnifies in one direction - typically horizontally.

The exact amount of magnification must equal the amount of electical scaling applied to the image.

The amount applied to video is based on 1.33x because 1.33 x 1.33 = 1.78, so 1.78 x 1.33 = (when rounded) 2.37. It simply takes the next step as well as provides an extension for 1.33:1 displays - IE you can obtain 1.78:1 optically by using a 1.33x stretch lens with a 1.33:1 projector...

Mark
Mark Techer is offline  
post #7 of 96 Old 02-02-08, 06:34 PM Thread Starter
HTS Senior Moderator
 
Prof.'s Avatar
The Mad Professor
 
Join Date: Oct 2006
Location: Murraylands South Aust
Posts: 8,367
My System
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Thanks Mark..

I hadn't been having much success at setting the correct white balance on the camera, until I came across your method of setting it...Worked a treat..

Prof..
Home Theatre...the never ending story!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Prof. is offline  
post #8 of 96 Old 02-07-08, 11:00 AM
Senior Shackster
 
Richard W. Haines's Avatar
Richard W. Haines
 
Join Date: Jul 2007
Location: Croton-on-Hudson, NY
Posts: 792
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

While in theory this makes sense, the cost is so expensive for the lenses is it worth it?
I'll put it this way. When I zoom up and eliminate the slight black borders on my 10
foot wide screen while watching the HD DVD of "The Wild Bunch", it looks almost as a
35mm print shown on the same size with anamorphic lenses and at the same distance
of 15 feet from booth to screen. What size screen are you using for comparison and
is worth the cost of the lens to remove the black borders and use more of the pixel field.

One of the disadvantages of using any anamorphic lens is that you lose some resolution when you compress and expand the image which is why 70mm widescreen looks so much better than a 35mm
anamorphic print even when the 70mm print was optically enlarged from a 35mm negative.
Richard W. Haines is offline  
post #9 of 96 Old 02-07-08, 06:06 PM
Mark Techer
 
Join Date: Jan 2008
Location: Brisbane, Australia
Posts: 613
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Hi Richard,

What projector are you using? Think of it this way - regardless of the rez, you will able to use the full rez of the projector all the time. If you take trueHD, you start with 1080 vertical pixels for 16:9 and progressively loose vertical pixels as the image gets wider. By the time you reach 2.35:1, you're down to about 810 vertical pixles.

One method is to zoom in the image. This is very much projector and placement dependent - some projectors just don't have enough zoom from a given throw. If your projector does have the range, what you end up with is enlargening of the pixels in both the horizontal and vertical directions. Seating distance pending, you may even see pixel structure.

The other method to to use an anamorphic lens. Yes some models are expensive, but there are also cost the effective approach that can work as well - see HERE. When you employ a 33% stretch lens, you are able to horizontally expand the image by 33%, but not affect the vertical rez. Researh has proven that we are more sensitive to vertcial rez than horizontal, so using an anamorphic lens keeps the pixels at the same height. And instead of throwing away about 270 pixels, you image is now made of the FULL 1080 vertical pixels. It is denser and more film like. I have seen systems that DO look as good (if not better) as 35mm film on a small screen (I define a small screen as anything less than 4.0m). It is like watching a brand new release print...

Mark
Mark Techer is offline  
post #10 of 96 Old 02-07-08, 08:59 PM Thread Starter
HTS Senior Moderator
 
Prof.'s Avatar
The Mad Professor
 
Join Date: Oct 2006
Location: Murraylands South Aust
Posts: 8,367
My System
Re: 16:9 Screen Vs. 2.37:1 CIH Screen

Quote:
Richard W. Haines wrote: View Post
While in theory this makes sense, the cost is so expensive for the lenses is it worth it?.
Unfortunately this is how many people view anamorphic lenses, and something way beyond their reach.. As a consequence, they don't even consider it as a possibility and don't look any futher into it..

Commercial lenses are very expensive, sometimes thousands more than some projectors..

I was of this belief about a year ago, and for me an anamorphic lens was just a dream..Something that I would never be able to afford, unless I won Lotto..

Then I came across Mark's Aussiemorphic lens, and for the first time it looked liked it would be possible to have an anamorphic lens..
I read everything I could find about it, and other peoples views on the lens who had purchased one..
and looked at a number of screenshots with the lens fitted..

I finally decided to buy one, still a bit hesitant as to whether I was going to get a quality lens or not, particularly when compared to lenses costing thousands of dollars..

Well to say that I was thrilled with the results would be an understatement..
I won't say what it cost me, except it was a fraction of the price of a commercial lens..

My point is this...You don't have to pay an arm and a leg to have an anamorphic lens..There are other ways of obtaining a lens that will perform almost as good as very expensive ones..
You can just buy the prisms, and put the lens together yourself..Or you can buy a lens kit (like mark's) and set it up yourself...

Believe me...If I can afford it...anyone can..

Prof..
Home Theatre...the never ending story!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
Prof. is offline  
Reply

Bookmarks

Tags
169 , cih , screen

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome