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12-636: The SF1 came in two different models varying in screen sizes. The larger SF1 unit featured a 21-inch screen and the smaller featured a 14-inch screen. Both units were colored gray, and both included a ROM-cartridge plugin-slot just above the screen. By merging the SFC and the television into one unit, the SF1 avoided the problem of exposed power cords and other cables. This gave the unit the advantage of being easier to handle. With internally connected SFC-SF1 terminals, luminance and chrominance signals could be separated, and

24-443: A particular bandwidth. Luma is the weighted sum of gamma-compressed R′G′B′ components of a color video—the prime symbols ′ denote gamma compression . The word was proposed to prevent confusion between luma as implemented in video engineering and relative luminance as used in color science (i.e. as defined by CIE ). Relative luminance is formed as a weighted sum of linear RGB components, not gamma-compressed ones. Even so, luma

36-470: Is sometimes erroneously called luminance. SMPTE EG 28 recommends the symbol Y ′ {\displaystyle Y'} to denote luma and the symbol Y {\displaystyle Y} to denote relative luminance. While luma is more often encountered, relative luminance is sometimes used in video engineering when referring to the brightness of a monitor. The formula used to calculate relative luminance uses coefficients based on

48-567: The CIE color matching functions and the relevant standard chromaticities of red, green, and blue (e.g., the original NTSC primaries, SMPTE C , or Rec. 709 ). For the Rec. 709 (and sRGB ) primaries, the linear combination, based on pure colorimetric considerations and the definition of relative luminance is: The formula used to calculate luma in the Rec. 709 spec arbitrarily also uses these same coefficients, but with gamma-compressed components: where

60-698: The SMPTE 240M coefficients: These coefficients correspond to the SMPTE RP 145 primaries (also known as "SMPTE C") in use at the time the standard was created. The change in the luma coefficients is to provide the "theoretically correct" coefficients that reflect the corresponding standard chromaticities ('colors') of the primaries red, green, and blue. However, there is some controversy regarding this decision. The difference in luma coefficients requires that component signals must be converted between Rec. 601 and Rec. 709 to provide accurate colors. In consumer equipment,

72-550: The back of the "console" portion of the set, and a cover could be applied to prevent dust. Doubts over the awkward attachment of expansion peripherals were among the reasons the unit never ultimately saw an international release. Despite the graphical superiority and general future-proofing, the SF1 only supports mono audio. Only two models were released in Japan. Luminance (video) In video , luma ( Y ′ {\displaystyle Y'} ) represents

84-604: The brightness in an image (the "black-and-white" or achromatic portion of the image). Luma is typically paired with chrominance . Luma represents the achromatic image, while the chroma components represent the color information. Converting R′G′B′ sources (such as the output of a three-CCD camera ) into luma and chroma allows for chroma subsampling : because human vision has finer spatial sensitivity to luminance ("black and white") differences than chromatic differences, video systems can store and transmit chromatic information at lower resolution, optimizing perceived detail at

96-666: The earlier Sharp Nintendo Television, AV output terminals were made readily accessible on the SF1's extended terminal which allowed connection to later peripherals such as the Satellaview . The C1 had been notably unable to connect to the Family Computer Disk System , and the SF1's design was intended to alleviate this problem with any Super Famicom peripherals. To use the extended terminal, the Satellaview's AV output terminal would attach obliquely upward on

108-421: The luminance of an image. Note the bleeding in lightness near the borders. Due to the widespread usage of chroma subsampling , errors in chroma typically occur when it is lowered in resolution/bandwidth. This lowered bandwidth, coupled with high frequency chroma components, can cause visible errors in luminance. An example of a high frequency chroma component would be the line between the green and magenta bars of

120-522: The matrix required to perform this conversion may be omitted (to reduce cost), resulting in inaccurate color. As well, the Rec. 709 luma coefficients may not necessarily provide better performance. Because of the difference between luma and relative luminance, luma does not exactly represent the luminance in an image. As a result, errors in chroma can affect luminance. Luma alone does not perfectly represent luminance; accurate luminance requires both accurate luma and chroma. Hence, errors in chroma "bleed" into

132-408: The prime symbol ′ denotes gamma compression . For digital formats following CCIR 601 (i.e. most digital standard definition formats), luma is calculated with this formula: Formats following ITU-R Recommendation BT. 709 (i.e. most digital high definition formats) use a different formula: Modern HDTV systems use the 709 coefficients, while transitional 1035i HDTV (MUSE) formats may use

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144-448: The resulting image quality was notably sharper than standard setups. This advantage diminished to a degree in the 14-inch model where picture quality was reduced. Additional functions were added to the remote control such that the SFC portion of the unit can be reset by simultaneously pressing two buttons. Additionally, the remote control could be used to record gameplay on the VCR. Unlike

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