Re: Fotos con filtro B&W
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Quote:<hr> Anamorphic Lenses Don't Just Give You widescreen For Free...
In the case of the AE-700 you go into ZOOM1 mode (that's the PAL name... it may have a different name with NTSC video, maybe just "ZOOM"<img src=https://www.mundodvd.com/forum/emoticons/wink.gif ALT="

"> . Whatever, this is the mode that zooms only vertically. It keeps the width of the projected image unchanged. So what you end up with is a 2.35:1 (Cinemascope) picture filling the whole 16:9 AE-700 screen i.e. using all the pixels. Of course, due to the differences in the aspect ratios between 2.35:1 (actually 64:27) and 16:9 everyone looks tall and skinny, circles are egg-shaped etc... the geometry's wrong.
What the anamorphic lens does is widen the 16:9 picture by 1.33:1, making it 64:27 (called "2.35:1"<img src=https://www.mundodvd.com/forum/emoticons/wink.gif ALT="

"> while maintaining the height and restoring correct geometry. Circles are circles again, faces look normal... except that the screen is now full frame Cinemascope... no black bars top and borrom of the screen to distract you AND it uses ALL the pixels of the AE-700 to do so.
Using an anamorphic lens means you don't have to zoom your picture to a large size, just to get the right width for a Cinemascope movie. You only have to set it to the correct HEIGHT. The lens then widens it out to Cinemascope ratio. This means that if you swing the anamorphic lens out of the way you have normal 16:9 pictures again, without needing to re-adjust your zoom factor to reset the height for the different aspect ratio.
Having to zoom your AE-700 projection lens less means a brighter picture to start with, and since you're only widening this smaller picture by one-third and in one direction you only lose 25% of that extra light (not 33% as some believe).
Smaller height also means that pixels are closer together, so your Cinemascope aspect image pixel-to-pixel is finer in detail vertically compared to the "traditional" technique of enlarging the whole picture and just watching the image between the black bars. You're using ALL the 720 vertical pixels to fill your screen vertically, not 3/4 of them. Horizontal pixel resolution is the same either way, so there's a nett significant gain in smoothness of image (this time it IS 33%).
Anamorphic lenses have been around for a while (since at least the 1920s). But they were first used in a big way when Cinemascope movies were introduced in the early 1950s. Cinemas all over the place had standard 4:3 aspect ratio projectors. By shooting the movie with an anamorphic (to squeeze the wide field of view in a 4:3 frame of film) and then projecting it with a "reverse" anamorphic lens (to widen the film out again), cinemas only needed to make modest adjustments to their equipment to accommodate the new format.
This is how most widescreen films are projected today. There were a few spherical lens widescreen techniques (Cinerama and Vistavision were two notable ones), but the cost of extra-wide film stock meant that the use of anamorphic lenses (using standard film stock) was the most economical.
There are two methods used to widen pictures anamorphically: one uses two counter-rotating prisms and the other uses cylindrical lenses. The prism technique was the original Panavision product, way back in 1952. It is also used in Prismasonic and Panamorph lenses for HT today. But these are incredibly bulky and heavy compared to a small form-factor cylindrical lens attachment. They also get in the way of IR remote signals to the projector and/or DVD player due to the bulk. And they have distortion when used in wide cone, short throw situations. The lens I have is cylindrical and has none of these problems. It weighs only four or five ounces and is 70mm wide by 80mm long (about 3 x 3.5 inches). There are other cylindrical lenses available for HT use, but the last I saw these can cost over $3,000 US. The one I purchased new was under $500, and as far as I can see, the pictures are superb.
As I reckon 16:9 will be the standard for HT projectors for the forseeable future, an anamorphic lens will always come in handy, as I upgrade to higher definition projectors in the future. Cinemascope aspect will never fit into 16:9 aspect ratio screens. So the adapter is Future Proof as well.
A word on masking: if you stand outside the image area and can see bright light coming from the projector lens then this is, by definition, stray light. If you hold your hand near the screen you can see a sharp shadow from these stray rays. These stray rays must decrease contrast, as they also fall within the screen area, lightening blacks. Sticking some black electrical tape on the face of the flat output element of my anamorphic lens eliminates most of this non-image stray light coming from the projection lens at the source, so I get the benefit of "masking" as well. Just about the only light that goes into the room is the actual image. This alone increases contrast by an appreciable amount, so much so that I've stopped using the Lee filter I was using. The picture is that good now that I am using all the pixels of the LCD panel and am masking any strays at the projector end. Most of my films are now projected in NORMAL mode in the projector and STANDARD at the DVD. I always have higher DVD outputs and VIDEO and DYNAMIC for particularly dull, low contrast movies. It's really the best of both worlds.
A random discovery:
A curious thing happened when I was setting up my new lens. Anamorphic adapters (cylindrical or prismatic) need to be aligned accurately with the projection lens (the center pixel of the image needs to pass through the center of both elements in the adapter), so I used SERVICE MODE to aid in doing this. While checking out focus and linearity with the SERVICE MODE cross-hatch pattern, I accidentally hit the COLOR MANAGEMENT button. To my surprise I got BOTH cross-hatch AND picture on screen at the same time. Quite useful, as now I could see both a geometrical AND a real DVD image together to get my alignment perfect.
To get out of this funny mode, just go through the SERVICE MODE routine again and turn it off with the MENU button.
I have v1.3 s/w. I hope they haven't fixed this very useful "bug" in later versions.<hr></blockquote>
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