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Alaska Business License # 712765
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The quality of a digital image depends on the resolution of the recording and output devices, and the file format selected to record and store the image. Under most conditions, digital imaging technology is at the point where it is capable of providing better sound and viewing than most people can detect and can provide image quality comparable to film technology. The best starting point regarding getting the best quality digital image is to determine; what do you expect, how will you be using it, and does the digital devices being used provide the means to do it. Like film--lens aperture, lens resolution, and lighting condition have direct bearing on what the digital sensors receive to record. However, digital devices differ from film in how they capture and record an image. Film captures an image on an entire frame all at once using a purely chemical process to record the image directly in the emulsions on the acetate. Digital and video, however, uses an electronic charged-coupled device (CCD) to capture images line by line, from left to right, and from top to bottom and then stores a file of binary numbers describing the image on different types of media such as video tape, CD-ROM, DVD or as digital information in a computer memory. Scanners and digital cameras have a 1:1 pixel aspect ratio (square). The vertical pixel line is the same length as the horizontal pixel line. Video devices have non-square pixel aspect ratios as the vertical pixel line maybe longer or shorter than the horizontal pixel line depending upon the video standard used. Consequently, a simple comparison of describing quality of image between film, digital, and video is not simple. Most discussions regarding which technology provides the best image quality immediately focus on resolution because it has the greatest impact on how much image detail a digital or chemical sensor records and gives you to see. These discussions (debates) regarding resolution capabilities of different imaging technologies is confusing and difficult to understand because of four reasons: (1) there is no consensus of the math used to figure number of horizontal lines; (2) number of horizontal lines is not a counting of the number of visual decreasing sized lines used to determine lpi (lines per inch). The more lines the count has, the higher the resolution; (3) film’s chemical sensor has no pixels, and the emulsion when applied sets up in a random grain pattern. Math and lpi data provides the estimated film image resolution; and, (4) pixel resolution is the number of addressable pixels in an image expressed in terms of numbers on a horizontal and vertical axis. The horizontal component is multiplies by an agreed upon value to obtain the number of horizontal lines. It is vital to understand that only lpi or lp/mm expresses resolution; dpi, ppi, and number of horizontal lines are not themselves discriminators of optical resolution. Film resolution depends on the optical system, the size of the film (35mm, 16mm or 8mm), and the quality of the number of light-sensitive crystals present in each square millimeter of film. Larger frame film has better resolution than small frame film. Digital resolution is a function of the number of photodiodes and their relative size relative to the image projected onto the CCD surface by the device’s optics. Determining the actual system resolution (optics, CCD, storage format) is a simpler process for scanners and digital cameras than it is for video devices. Digital camera resolution is rated in CCD mega pixels and scanner resolution is rated in maximum hardware resolution. Camcorder resolution is rated in CCD mega pixels, number of CCDs, and type of image fields per second. Quality digital devices also allow for the capture of a wide dynamic range of color and shade and can optically distinguish subtle differences in luminosity, even shadow area and then store this data. High-resolution images have high pixel counts and are best for making large prints. Low-resolution images have low pixel counts and are good for making small prints, use on the Internet, and e-mailing. A 3CCD (charged coupled device) digital camcorder capable of 525 lines, 60 image fields per second (NTSC) is the minimums standard for North American television broadcast editing with maximum resolution and highest audio quality. The predominant European standard is 625 lines, 50 image fields per second (PAL). High Definition television (HDTV) is digital TV in its highest and best form; it is capable of 1125 lines, 60 image fields per second. HDTV digital camcorder’s capable of 1080 lines and progressive scanning may capture image resolution equal to or exceed the image quality of 35mm film. Film technology predominated the documenting of family activates and events from 1888 until video and digital technology began replacing it in the 1980s. The transition from film to digital brings with it advantages and disadvantages relevant to resolution and depth of detail each technology is capable of producing in a recorded image. These differences become a concern when deciding how best to preserve old photographs, movies, and videos that are showing the effects of wear and tear or perhaps poor storage techniques. The professional level 3CCD digital video camcorder recording to digital video tape provides the best solution for making the best resolution and overall quality image copy of your filmed home movies. DVD-video resolution is lower than digital videotape, but DVD offers ease of use features useful if you watch the movie frequently or want to share copies with friends and relatives. Whether you transfer film to digital videotape or DVD-video, digital technology provides the best copying capabilities without critical tradeoffs. It is the most economical too. Resolution is pertinent in selecting the technology for preserving or copying film clips. 8mm, super8, and 16mm film have about 1315 lines of resolution and a good film projector probably has the ability to project this resolution into a screen image of about 3 feet wide. A film projector simply projects complete frames of still images at a certain rate. Digital technology, however, must draw each image line by line on a screen and display complete frames of images at a certain rate. Any device copying images from an original film clip must also cope with overcoming the grain noise of the chemical emulsions holding the image on film and the knowledge that any second generation copy of an original film image will lack some sharpness and depth of detail captured in the original image. What this means is a copy of an original will have less quality and then a copy of the copy will have even less quality. The ability of a digital device to most accurately and perfectly copy an original film image depends upon the devices specification relevant to type of image sensor, signal noise, pixel count, number of recording pixels, image format, lines of horizontal resolution, and numerous other factors. Seeing the best professional quality output of your digital images involves more than recording images with camera, scanner, and camcorder. Selecting the proper storage format, color management setting, and image pixel count needed for printing, screen viewing, or restoring images is also part of the digital imaging process. Digital imaging is economical, simple to use, and provides the means to save or copy precious memories. Digital imaging is the ability to make exact copies of original digital images at any time from either the original digital image or any existing copy of it. Digital imaging is the fun and interesting way to share memories. CY Technical and Professional Services is ready and capable of giving you the keepsake digital memories you expect. |
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