SMPTE ST 420M-2005 for Motion-Picture Film 70-mm - Projectable Image Area 8 70 Format.pdf

1、 1 Scope This standard specifies the maximum dimensions of the film image area intended for projection from an 8/70 special-venue motion-picture film, and the placement of this area relative to the perforations and the reference edge of the film. 2 Normative references The following standards contai

2、n provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreement based on this standard are encouraged to investigate the possibility of applying

3、the most recent edition of the standards indicated below. SMPTE 119-2004, Motion-Picture Film (70-mm) Perforated 65-mm, KS-1870 SMPTE 418M-2005, Motion-Picture Film (65-mm) Camera Aperture Image and Usage, 8/70 Format 3 Dimensions The dimensions shall be as given in figure 1 and table 1. Page 1 of 3

4、 pages SMPTE 420M-2005 Copyright 2005 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 ApprovedOctober 18, 2005SMPTE STANDARD for Motion-Picture Film 70-mm Projectable Image Area, 8/70 Format SMPTE 420M-2005 Page 2 of 3 pages Figure 1 P

5、rojectable area of film (Looking toward lens, facing emulsion side) Table 1 Specifications Dimensions Description Inches Millimeters A Projectable width 1.912 max 48.56 max B Projectable height 1.417 max 36.00 max C Reference edge to image centerline 1.377 ref 34.98 ref D Reference edge to image 0.4

6、20 min 10.67 min E Reference edge to image 2.334 max 59.28 max F=H Projection edge centered to perforations within 0.008 within 0.20 J=K Projection centerline to perforations nominally equal nominally equal NOTES 1 Aspect ratio. The nominal projected aspect ratio of this film system is 1.35:1. Howev

7、er it should be understood that material cross-printed to this format from a different-format source may result in non-standard frame boundaries. 2 Camera vs. projector aperture. The actual image on the film is significantly larger than the maximum area intended for projection, such that no portion

8、of the image will be cropped prior to the projector aperture. SMPTE 420M-2005 Page 3 of 3 pages 3 Projector aperture vs. projectable area. Dimensions A, B, D, and E define the maximum area on the film that is available for projection. They do not define the opening in the aperture plate of a project

9、or. The size of this opening may differ from dimensions A and B, for example, because of the physical separation necessary between the aperture plate and the film to avoid scratching the film, the slant of the marginal rays accepted by the projection lens, etc. 4 Projected area distortions. It is re

10、cognized that, in many cases, the actual film image area that is projected may be smaller than the projectable maximum and, in some cases, may be nonrectangular (for example, an irregular four-sided figure bound by either straight or curved lines). Such departures may result from equipment considera

11、tions, such as slight inconsistencies among lenses, screen sizes, etc.; from geometric limitations such as the screen surface being at an angle other than 90 from the projection axis, or being nonplanar, or both; from aesthetic considerations such as pictorial composition within more restrictive ima

12、ge limits; and finally, architectural limitations of the venue itself. It is intended that the actual projected film image area be the largest appropriately-shaped figure that can be inscribed within the specified dimensions. 5 Perforation. Film intended for projection in this format shall be perforated as specified in SMPTE 119.