2.35:1 Projection

I currently have a 16:9 front projection system, I am thinking of upgrading to a 2.35:1 screen and projector, as I watch mainly movies. I think I want a projector that will project natively at 2.35:1, with black bars on the sides for 16:9 material. What is that feature called? The projector would need to be either DLP or LCOS. Are there any such projectors out there now, or maybe on the near horizon? Any other thoughts you have would be appreciated.

Mike Weyer

I know of only one projector that can display 2.35:1 natively—the projectiondesign Optix SuperWide 235 (seen here)—which was announced at CEDIA last year. However, I don't know if it's available yet, and even if it is, the price was announced to be in the $40,000 range.

What you want is known as "constant-height projection," and there are a couple of ways to accomplish it with a 16:9 projector. One method is to place an extra lens in front of the projector's primary lens. This so-called "anamorphic" lens optically stretches the image horizontally, which means the projector (or an outboard video processor) must electronically stretch or scale the image vertically in order to fill a 2.35:1 screen. Anamorphic lenses cost at least $5000, and in some cases a lot more.

The projectiondesign Optix 235 does not require an anamorphic lens, but it does scale a 2.35:1 movie on Blu-ray from 1920x817 to 2560x1080, which could introduce scaling artifacts.

There are two ways to mount the anamorphic lens—in a fixed frame or a motorized sled. If the lens is mounted in a fixed frame, the projector's processor must be able to process a 16:9 image so it fills the height of the screen, which means the image is scaled horizontally with black bars on the sides. A motorized sled moves the lens into and out of the light path depending on whether the image is 2.35:1 or 16:9, which avoids the extra horizontal scaling. Of course, a motorized sled is quite expensive in and of itself.

A third, less-expensive option is to find a projector with "lens memories." Such a projector can store different zoom and focus settings that fill the height of the screen with a 16:9 or 2.35:1 image, and you simply select the memory that corresponds to the image you are watching. In this case, no scaling is needed, but the black letterbox bars of a 2.35:1 movie are zoomed outside the screen area. Very few projectors offer lens memories—one is the Panasonic PT-AE4000U, an LCD model that lists for $2500.

There is considerable debate about the pros and cons of anamorphic lenses. Proponents argue that this approach uses all the pixels provided by the projector, while skeptics point out that vertically scaling the image can degrade the picture quality, as can the horizontal scaling for 16:9 images with a fixed anamorphic lens. Also, the more glass the light must pass through, the more chance for optical distortion—in fact, curved screens are often used with anamorphic setups to compensate for a particular type of optical distortion. (Note that the projectiondesign Optix 235 does not require an anamorphic lens, but it does scale a 2.35:1 movie on Blu-ray from 1920x817 to 2560x1080, which could introduce scaling artifacts.)

A projector with lens memories suffers from none of these problems, but the vertical resolution of a 2.35:1 movie is only 817 pixels.

If you have an A/V question, please send it to askhometheater@gmail.com.

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COMMENTS
dlbthx62's picture

Optoma DLP projectors(HD8200) have a feature called Superwide. It scales both 16:9 and 2.35:1 image to 2.0:1. This aspect ratio is basically a half-way point between the other aspect ratios. You do lose about 7% of pixals used to create the image, that is still better than the 30% unused pixals with letterboxing and the zoom out feature. This is cheaper than buying an anamorphic lens. The drawback is getting a screen with that aspect ratio( Carada can manufacture them) and some possible artifacts due to scaling. I did not see any in my set up( 120in 1.4 gain 2.0:1 screen ). This alternative does NOT completely eleminate the black bars but the black backs are barely noticable and you are using almost all the 1080p pixals to create the image.

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