Anamorphic widescreen
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Anamorphic widescreen is a cinematography and photography technique for capturing a widescreen picture on standard 35mm film, or other visual recording media with a non-widescreen native aspect ratio. It can also refer to a related technique for maximizing picture quality in DVD video recordings.
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[edit] Background
Anamorphic widescreen in cinematography was first popularized with CinemaScope, which was one of many widescreen formats developed in the 1950s. The Robe was the first feature film released to use anamorphic photography, premiering in 1953. The development of anamorphic widescreen arose due to a desire for wider aspect ratios. The modern anamorphic widescreen format has an aspect ratio of 2.39 to 1, meaning the picture width is 2.39 times its height. "Academy format" 35mm film (standard non-anamorphic full frame with sound) has an aspect ratio of 1.37 to 1, which is not as wide (or, conversely, is too tall). In conventional spherical ("flat") widescreen imaging, the picture is recorded on film so that its full width fits within the film frame, and substantial film frame area is wasted on portions that will be matted out by the time of projection, either on the print or in the projector, in order to create a widescreen image in the theater (Figure 1).
To make full use of the available film, an anamorphic lens is used during recording; this lens effectively squeezes the picture horizontally so that (in the case of the common 2x anamorphosis lens) a frame twice as wide fills the available film area (Figure 2). Since a larger film area is being used to project the same picture, quality is increased. (The film frame itself is also very slightly larger.) The distortion introduced in the picture must be corrected when the film is played back, so another lens is used during projection that expands the picture back to its correct proportions. It should be noted that the picture is not vertically manipulated in any way—the normal anamorphic process instead uses a horizontally-oriented element to squeeze the width only.
It may seem that it would be easier to simply use a wider film for recording movies; however, 35mm film was already in widespread use, and it was more economically feasible for film producers and exhibitors to simply attach a special lens to the camera or projector, rather than investing in a new film format, along with the attendant cameras, projectors, and editing equipment.
Cinerama was an earlier attempt to solve the problem of high-quality widescreen imaging, but anamorphic widescreen eventually proved to be more practically feasible. Cinerama preceded anamorphic films, but consisted of three projected images side-by-side on the same screen: the images never blended together perfectly at the edges, and it required three projectors; a 6-perf-high frame, which required four times as much film; and three cameras (eventually just one camera with three lenses and three streaming reels of film and the attendant machinery, which presented interesting synchronization problems.) Nonetheless, the format was popular enough with audiences to spur studios to the wide screen developments of the early 1950s. A few films were distributed in Cinerama format and shown in special theaters custom-made for showing these movies, and many viewers were willing to travel many miles to see the films, but eventually, most viewers, most of the time, traveled lesser distances to see films that could be shown in ordinary theaters. Anamorphic widescreen was attractive to studios because of its similar high aspect ratio (Cinerama was 2.59) without the disadvantages that came with the Cinerama format's simultaneous reels and the complexity of synchronizing these reels.
The common anamorphic widescreen film format in use today is commonly called "'Scope" or 2.35 (the latter being a misnomer born of old habit; see "2.35, 2.39, or 2.40?" below). "Filmed in Panavision" is a phrase contractually required for films shot using Panavision's anamorphic lenses. All of these phrases mean the same thing: the final print uses a 2:1 anamorphic projector lens that expands the image by exactly twice the amount horizontally as vertically. This format is essentially the same as at the time of CinemaScope, except for minor technical developments.
There are artifacts that can occur when using an anamorphic camera lens that do not occur when using an ordinary spherical lens. One is a kind of lens flare that has a long horizontal line usually with a blue tint and is most often visible when there is a bright light, such as from car headlights, in the frame with an otherwise dark scene. This artifact is not always considered to be a problem. It has come to be associated with a certain cinematic look and is in fact sometimes emulated using a special effect filter in scenes that were not shot using an anamorphic lens. Another common aspect of anamorphic lenses is that light reflections in the lens will be elliptical rather than round, as they are in spherical cinematography. Additionally, wide angle anamorphic lenses of less than 40mm focal length produce a cylindrical perspective, which some directors and cinematographers, particularly Wes Anderson, use as a stylistic trademark.
Another characteristic of anamorphic camera lenses is that out-of-focus elements tend to be blurred more vertically. An out-of-focus point of light in the background will appear as a vertical oval rather than a circle. When the camera shifts focus, there is often a noticeable effect where elements appear to stretch vertically when going out of focus. An anamorphic lens will also have a more shallow depth of field compared to a spherical lens for a given aperture.
While the anamorphic scope widescreen format is still in use as a camera format, it has been losing popularity in favor of flat formats, mainly Super 35 mm film. In Super 35, the film is shot flat and can then be matted and optically printed as an anamorphic release print. There can be several reasons for this:
- An anamorphic lens can create artifacts as described above.
- An anamorphic lens is more expensive than a spherical lens.
- Because the anamorphic-scope camera format does not preserve any of the image above and below the scope frame, it may not transfer as well to narrower aspect ratios, such as 4:3 or 16:9 for full screen television.
- Film grain is less of a concern because of the availability of higher-quality film stocks and digital intermediates, although the anamorphic format will always yield higher definition than the non-anamorphic format.
Many directors and cinematographers who use the anamorphic format swear by it, shooting most if not all of their films this way. Directors known for their loyalty to the anamorphic format include Clint Eastwood, Wes Anderson, John McTiernan, Jan de Bont, Mel Gibson and Michael Bay. Many of the world's most renowned cinematographers, such as Donald McAlpine, Vilmos Zsigmond, László Kovács and John Schwartzman, shoot using the anamorphic process at every opportunity.
Other widescreen film formats (commonly 1.85:1 and 1.66:1) are simply cropped in vertical size to produce the widescreen effect, a technique known as masking or matting. This can occur either during filming, where the framing is masked in the gate, or in the lab, which can optically create a matte onto the prints. Either method produces a frame similar to that in Figure 1, and is known as a hard matte. Many film prints today have no matte, though the film is framed for the intended aspect ratio; this approach is called full frame filming, since most spherical 4-perf cameras retain the silent gate. In these, the film captures additional information that is masked out during projection using an aperture mask in the projector gate, and is known as soft matte. This approach allows filmmakers the freedom to include the additional picture in an open matte 4:3 transfer of the film and avoid pan and scan, by "protecting" the frame for 4:3.
[edit] 2.35, 2.39, or 2.40?
One common misconception about the anamorphic format concerns the actual number of the aspect ratio itself. Since the anamorphic lenses in virtually all 35mm anamorphic systems provide a 2:1 squeeze, one would logically conclude that a 1.37:1 full academy gate would lead to a 2.74:1 aspect ratio if used with anamorphic lenses. However, due to a difference in the camera gate aperture and projection mask sizes for anamorphic films, the image dimensions used for anamorphic film vary from "flat" (spherical) counterparts. To complicate matters, the SMPTE standards for the format have varied over time; to further complicate things, pre-1957 prints took up the optical soundtrack space of the print (instead having magnetic sound on the sides), which made for a 2.55:1 ratio.
The first SMPTE definition for anamorphic projection with an optical sound track down the side (PH22.106-1957), made in December 1957, standardized the aperture to 0.839 in by 0.715 in (1.17:1). The aspect ratio for this aperture, after a 2x unsqueeze, rounds to 2.35:1. A new definition was created in October 1970 (PH22.106-1971) which made the vertical dimension slightly smaller in order to make splices less noticeable (as anamorphic prints use more of the negative frame area than any other modern format) when projected. This new aperture size, 0.838 in by 0.7 in, (1.19:1) makes for an unsqueezed ratio of 2.39:1 (more commonly referred to as 2.40:1). The most recent revision, from August 1993 (SMPTE 195-1993), slightly altered the dimensions so as to standardize a common aperture width (0.825 in) for all formats, anamorphic and flat. At these modern dimensions (0.825 in by 0.690 in—1.19:1), the unsqueezed ratio remains at 2.39:1. <ref name="smpte">Hart, Martin.(2000). Widescreen museum "Of Apertures and Aspect Ratios" Retrieved July 8, 2006.</ref>
Anamorphic prints are still often called "Scope" or 2.35 by projectionists, cinematographers, and others working in the field, if only by force of habit. 2.39 is in fact what they generally are referring to (unless discussing films using the process between 1958 and 1970), which is itself usually rounded up to 2.40. With the exception of certain specialist and archivist areas, generally 2.35, 2.39, and 2.40 mean the same to most professionals, whether they themselves are even aware of the changes or not.
[edit] Lens makers
There are numerous companies that are known for manufacturing anamorphic lenses. The following are the best known in the film industry:
- Panavision: The most commonly used source of anamorphic lenses by far, they have several series of lenses which range from 20mm to a 2,000mm anamorphic telescope. The different series available are:
- The C-Series, which are the oldest lens series. They are small and leightweight, which makes them very popular for steadicam. Many cinematographers prefer these to later lenses because they are lower in contrast.
- The E-Series, which are Nikon glass. They are in general sharper than the C-Series and are better color matched. They are also faster but the minimum focus distance on the shorter focal lengths is not as good. The E135mm and especially the E180mm are great close-up lenses with the best minimum focus of any long Panavision anamorphic lenses
- The Super (High) Speed Lenses, also glass by Nikon, are the fastest anamorphic lenses available with Tstops between 1.4 and 1.8. There even is one T1.1 50mm. But like all anamorphic lenses they need to be stopped down to get a good performance, as wide open they are quite soft.
- The Primo and Close-Focus Primo Series, which are Panavision's latest anamorphic lens series. They are based on the spherical Primos and are the sharpest lenses available, as well as completely color-matched. But they are also very heavy (between 5 and 7 kilos).
- Vantage Film, makers of Hawk Lenses. They are based on Russian design, but have since been independently developed further. Their main characteristic is that they have their anamorphic element in the middle of the lens (not up front like Panavision) which makes them more flare resistant. This design choice also means that if they do flare, one does not get the typical horizontal flares. The following lens series are available:
- The C-Series, which were developed in the mid-nineties. They are relatively small and lightweight.
- The V-Series (2001) and V-Plus Series (2007). These lenses are an improvement over the C-Series as far as sharpness, contrast, barrel-distortion and close-focus are concerned. This increased optical performance means a higher weight however (each lens is around 4-5 Kilos). The Vs may not be as sharp wide open as the Primos, but they have a more ‘round’, organic look which looks especially pleasing on faces. Stopped down they become very sharp as well. There are 14 lenses in this series which goes from 25mm to 250mm. The V-Series also have the best minimum focus of any anamorphic lens series available and as such can rival spherical lenses.
- Joe Dunton Camera: Manufacturer and rental house based in England and North Carolina, which adapts spherical lenses to anamorphic by adding a cylindrical element. Their most popular lenses are adapted Cooke S2/S3, but they have also adapted Zeiss Super Speeds and Standards, as well as Canon lenses.
- Elite Optics, manufactured in Russia and considered among the highest quality anamorphic lenses available. They are sold in the United States by Slow Motion, Inc.
- Technovision a French manufacturer who, like JDC, also have adapted spherical lenses for anamorphic.
- Schneider Optics, (also called Century) makers of the most widely-used anamorphic projection lenses in the world. The company also manufactures add-on anamorphic adaptor lenses which can be mounted on digital video cameras.
- Panamorph, makers of the most widely-used anamorphic lenses specifically for consumer home theater projection systems.
[edit] Super 35 and Techniscope
Although many films projected anamorphically have been shot using anamorphic lenses, there are often aesthetic and technical reasons which make shooting with spherical lenses preferable. If the director and cinematographer still wish to retain the 2.39 aspect ratio, anamorphic prints can be made from spherical negatives. Because the 2.39 image cropped from an Academy ratio 4-perf negative causes considerable waste of frame space, and since the cropping and anamorphosing of a spherical print requires an intermediate lab step, it is often attractive for these films to use a different negative pulldown method (most commonly 3-perf, but occasionally Techniscope 2-perf) usually in conjunction with the added negative space Super 35 affords.
[edit] DVD video
A similar anamorphic technique is used to store video on DVD. DVDs using anamorphic widescreen make effective use of the available resolution, as well as allowing a film to automatically expand to fit widescreen television sets. Anamorphic widescreen DVDs store a horizontally squeezed picture to make more optimal use of vertical resolution by avoiding or decreasing wasted lines on the black letterboxing bars. Sources that are close to 16:9 can be transferred to DVD taking up the entire 16:9 frame with no wasted space. However, sources that are wider than 16:9, such as 1.85:1 or 2.39:1 video, must still be letterboxed into the 16:9 frame with varying amounts of black bars.
When a DVD is inserted into a player, the player will do one of two things depending on the type of television set in use:
- if the DVD player is set up to output a widescreen image, and the tv monitor is widescreen, the player will send an anamorphic (horizontally-squeezed) signal to the TV, which will compress the scanlines of the displayed image vertically to fit the frame on the screen. The vertical compression of the scanlines restores the video back to its original widescreen aspect ratio with a perceived 25%-30% increase in horizontal resolution since more of the lines are being used for picture information and are being scanned more tightly together by the display.
- If the DVD player is set up to output a letterbox picture, the DVD player processes the picture through scanline elimination or interpolation algorithms to restore the correct aspect ratio, and adds letterbox-style "black-bars" before sending the signal to the display device (setting for non widescreen tv monitors). This results in a loss of horizontal resolution of the image since the extra scanlines are either eliminated or interpolated out of the picture, which results in an image with jagged rendition of any diagonal lines or an overly softer picture, respectively.
This technique is not used on all DVDs; some use the standard letterboxing technique. Those that do use the anamorphic technique typically specify "anamorphic widescreen", "enhanced for 16:9", "enhanced for widescreen televisions" or a similar statement on the packaging, though there is currently no widely accepted standard for such labeling. If a DVD claims to be widescreen, but does not have a label like one of the previous, it may use the standard letterbox technique, resulting in decreased resolution for widescreen pictures. Some DVD packaging explicitly mentions that the lower-quality letterbox technique is used; when viewing such a letterboxed DVD on a widescreen display, it may be necessary to zoom in on the picture in order to utilize the full width of the screen.
[edit] Anamorphic lens enhancement
Image:DVD-Video enhancement using anamorphic lens.gif Since the anamorphic widescreen standard for DVDs includes letterboxing for aspect ratios wider than 16:9, the display device will still lose some resolution to the display of black bars for wider formats such as 2.39:1 films. This wasted resolution can be eliminated by using a front projector in conjunction with an anamorphic lens and a video processor: first, the video processor or scaler (such as an HTPC) stretches the video up to the full resolution of the projector, eliminating the wasted resolution but also distorts the image vertically. As the distorted image is projected, it passes through an anamorphic lens which will either shrink the video vertically or expand it horizontally, restoring the original aspect ratio in both cases<ref name="calculator">prismasonic.com Screen size calculator for conversion by anamorphic lens</ref>. Depending on the quality of the scaler and the lens, the end result is potentially a smoother video due to increased vertical resolution. If the anamorphic lens shrinks the image vertically, there is an added advantage of increased brightness, since light output has been condensed. In contrast, an anamorphic lens which stretches the image horizontally will also decrease its brightness. A similar approach can be used to convert a 4:3 projector into a 16:9 projector<ref name="calculator" />, or a 16:9 projector into a 4:3 projector (by rotating an anamorphic lens by 90 degrees).
