Grass Valley KAM-XM-SERIES v.1.4.1 - Manual (Page 23)

KAM-XM-SERIES Instruction Manual 23
Configuration and Adjustments
Aspect Ratio Modes
Most SD material is in a 4:3 aspect ratio while HD material is 16:9. Aspect
ratio in this case refers to the ratio of an image width to height, not related
to image size. The effect of aspect ratio in up conversion (4:3 to 16:9) is a
process of cropping, stretching, or squeezing the image. To address these
issues, the module provides a control for selecting one of three standard
aspect ratio conversion options:
• Anamorphic – this mode is designed to be used with material originally
captured with an anamorphic lens. It ensures that the top and bottom
edges of the input aspect ratio match the top and bottom edges of the
output aspect ratio. When used with standard 4:3 material, it will have
the effect of stretching the material horizontally as illustrated in
Figure 9 . This results in a distortion of the geometry of the image, par-
ticularly causing circles to appear as ovals when present in the image.
Figure 9. 16:9 Anamorphic Mode
• Common Top & Bottom – this mode ensures that the top and bottom
edges of the input image match the top and bottom edges of the output
aspect ratio. A 4:3 image set to this mode will appear centered in a 16:9
display with black bars, or pillars (pillarbox), on the left and right sides
as illustrated in
Figure 10 .
Figure 10. Common Top and Bottom Mode
16:9 conversion with horizontal stretch 4:3 Original