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..

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..

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.

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

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

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

Richard W. Haines said:

While in theory this makes sense, the cost is so expensive for the lenses is it worth it?.

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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..

tonyvdb said:

Hi Prof, Im interested in looking into doing this sometime down the road but have a few questions. Where do you get this lens you speak of, I went to the link but dont see a price or place to buy it.

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Tony, I bought my lens from Mark Techer, who is the maker of the Aussiemorphic lens..this link should give you all the info. you need
http://cavx.blogspot.com/2007/04/4-prism-lens.html

Also will it work on any projector? I just have a Sanyo Z2.

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Shouldn't be a problem..Mark's lens works on just about all projectors..

When you say affordable what do you mean by this as thats a relative word when dealing with little to no budget.

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Well I bought the Mk.1 lens and it cost less than $400AUD...the Mk.11 is a little dearer, but it now comes with coated optics and a slide mount..

BUT...you can even do it for a lot less if you're prepared to make up your own lens, by just buying a couple of prisms and assembling them into a case..

I would suggest sending a pm to Mark and ask him about how to get hold of some prisms...
You might like to click on this link as well...http://cavx.blogspot.com/2008/01/b-stock-prisms-for-sale.html..

When you are ready to set up for CIH projection and assembling the lens, Mark will give you all the help you need to correctly set up the lens...