Motion Picture Film Scanning & Recording Systems
	Film Scanners  |  Film Recorders  |  Company  |  Support  |  Contact	Telecine vs. Scanning

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Telecine is Dead!

Moore's law in computing performance and storage capacity has made the traditional telecine film transfer model obsolete. In recent years, the film transfer process has transitioned from the use of traditional telecine equipment (e.g. Spirit, Cintel) that outputs only video, to modern film scanners (e.g. ScanStation, Director, ARRISCAN, etc.) that output digital files in a variety of formats.  A transition driven by the increasing quality of image scanning technology coupled with an explosive growth in computing power and storage capacity.

Telecine Image Quality is Inferior to Scanners

Real-time scanning was required in the old days when the only viable image "pipe" was a real-time video channel. In those days, everything had to be sacrificed for speed. As a result, telecines generated real-time video at the expense of noisy and highly unstable images (all telecines are edge-guided which causes extensive weaving).

With the advent of the Digital Intermediate (DI) process, the low quality output of the telecines was replaced with the dramatically higher quality output of DI scanners (e.g. the Lasergraphics Director, ARRISCAN, Northlight, etc.).  These scanners do not need to output real-time video.  Instead, they generate data files.  As a result, these scanners can take the time to generate significantly superior images that are very low-noise and extremely stable.

For example, the Northlight scans at less than 1 frame per second, the ARRISCAN scans at rates ranging from 4 to 8 frames per second, and the Lasergraphics Director scans up to 15 frames per second. The reason for this non-real-time scanning speed is simply this: QUALITY.

Telecine Images are Unstable

All telecines use the edge of the film to keep it registered in the gate.  This practice is called “edge-guiding”. Film aligned to edge Image sensor aperture Typical telecine gate However, motion picture cameras do not use the edge of the film while exposing.  Instead, they use the film perforations.  The spacing between the edge of the film and the perforations is not well controlled by film manufacturers.  The SMPTE 93-2005 specification for 35mm film dimensions allows for a margin of ±2 mils between the perforations and the edge.  This corresponds to an error of ±4 pixels at 2K resolution. Film scanners that directly use the perforations of the film to align each frame separately improve alignment accuracy to approximately 1/5 of one 2K pixel.  This represents an improvement in stability of over 20 times compared to edge-guided telecines and telecine-like scanners. Pins Mechanical pin registration is great for new film but bad for damaged or shrunken film. More modern film scanners use optical pin registration to stabilize the image.   Film registration is achieved by optically sensing one or more perforations as a guide.

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Lasergraphics' proprietary 2D optical pin registration system locates up to 8 perforations and is able to register the frame even if only one of the perforations is usable.  The frame is stabilized in the X, Y, and rotation axes.  Therefore, shrunken film can be effectively stabilized with no mechanical or software adjustments.  All optical pin registration is performed during the scanning process, eliminating the need for any post-processing.

Lasergraphics scanners are highly immune to perforation damage and splices while maintaining registration.  Lasergraphics' 2D optical pin registration detects the location of all of the holes and then determines which ones are damaged.  The damaged ones are ignored while the undamaged ones are used to align the image.

• mechanical pin registration, which engages the film in only two perforations and is only effective on undamaged and unshrunken film.
• edge guiding, which weaves laterally because it entirely ignores the holes and is highly intolerant of splices.

Telecines are Splice Intolerant 

Edge-guided telecines and film scanners can not handle splices well.  Splices cause a lateral shift in the image position when they touch the edge guide, which in turn creates lateral color shifts in the image.

Splice Lateral color shifts Enlarge image

Optical pin registration eliminates the film registration problems caused by film splices.

Splice Enlarge image

Telecine Images are Susceptable to Banding 

Vertical banding caused by dirt in the line imager aperture causes 23 DPX code non-uniformity (i.e. 2%) Telecines and telecine-like scanners move the film continuously past a thin aperture, corresponding to its line image sensor.  As a result, dirt builds up in the line aperture during scanning.  The dirt that accumulates in the scanning aperture blocks some of the light in subsequent frames.  This causes subtle intensity differences which appear as banding in the image. For area imagers, this dirt typically remains outside of the active image area because the scanning aperture is oversized.

Area Imager Aperture Dirt always accumulates near the edge of the scanning aperture during scanning. For modern film scanners, this dirt typically remains outside of the active image area because the scanning aperture is oversized. Enlarge image For modern film scanners, this dirt typically remains outside of the active image area because the scanning aperture is oversized.

Telecines can't Detect and Eliminate Dust

Film scanned on a telecine invariably contains dust in some frames and has no means of automatically detecting or eliminating these defects. The Director film scanner incorporates Digital ICE Technology from Kodak which works during scanning to detect and reduce dust and surface scratches without softening, blurring, or altering the image.  A defect matte is generated, depicting pixels that have been automatically corrected and defects that require additional attention (if any).  So, if a defect is found that is greater than what can be corrected automatically by the system, DICE will identify it so the post house can easily locate and address the issue.

Original scan   Defect matte is created   Corrected image

Telecines can't handle Warped Film

Telecine Film Gate Doesn't lay flat resulting in bad focus

The Director Film Gate Warped film held flat on 4 sides with pressure plate for superior full-frame uniform focus