SMPTE RP 94-2000 Gain Determination of Front Projection Screens《前投影屏幕的增益测定》.pdf
《SMPTE RP 94-2000 Gain Determination of Front Projection Screens《前投影屏幕的增益测定》.pdf》由会员分享,可在线阅读,更多相关《SMPTE RP 94-2000 Gain Determination of Front Projection Screens《前投影屏幕的增益测定》.pdf(2页珍藏版)》请在麦多课文档分享上搜索。
1、STD-SMPTE RP 94-ENGL 2000 83574011 0004376 954 ei SMPTE RECOMMENDED PRACTICE Gain Determination of Front Projection Screens RP 94-2000 Revision of RP 94-1993 Introduction Screen gain is the ratio of the test luminance to the luminance of a lambert diffuser under the same viewing conditions and angle
2、. Screen gain varies with the angle of view, because of the laws of reflection and the nature of the screen surface. Screen gain is basically directional and, thus, the maximum screen gain number is misleading be- cause it is an incomplete description as it relates to an entire screen. The hot-spot
3、on a screen is the full screen gain in operation at that spot. 1 Scope This practice specifies a method for measurement of screen gain. 2 Formula Screen gain is a ratio: Luminance of test screen Luminance of lambert diffuser Gain = 3 Measurement 3.1 The test screen sample shall be illuminated with d
4、iscrete projection lamp light rays at or near perpendicular to the screen surface, in a dark- ened room area (see annex A.2). 3.2 The luminance of the screen sample shall be measured at 5-degree intervals. The measurements Page 1 of 2 pages shall be in the horizontal plane (and vertical, if differen
5、t) that pass through the perpendicular to the screen surface. 3.3 The maximum gain shall be labeled as such. The maximum gain advantage is assumed to have rolled off to below 1 .O at 30“ off axis unless otherwise noted. 3.4 In testing screens already installed in theaters, the methods specified in 3
6、.1 and 3.2 may be altered to accept the existing projection angle and seating arrangements (see annex A.l). 4 Instruments 4.1 The goniophotometer shall measure only the luminance of the perpendicularly illuminated area on the screen. 4.2 The photometer (see 4.1) shall have a spectral response of a s
7、tandard observer with photopic vision (see annex A.6). 4.3 A diffuse reference standard similar to a lambert diffuser, which reflects all incident light so that the luminance is the same regard- less of the angle of view, shall be used and shall be specified with the screen gain. The standard could
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
10000 积分 0人已下载
下载 | 加入VIP,交流精品资源 |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- SMPTERP942000GAINDETERMINATIONOFFRONTPROJECTIONSCREENS 投影 屏幕 增益 测定 PDF

链接地址:http://www.mydoc123.com/p-1046562.html