I. Viewing distance limitation
For naked-eye 3D stereo display technology, the distance between the viewer’s position and the screen (i.e., viewing distance) will directly affect the presentation of the stereo effect.
1）Optimal viewing distance range:
Assume that the optimal viewing distance of a naked-eye 3D display device is 1.5 meters to 2 meters in front of the screen. This range is determined based on the specific design and parameters of the device to ensure that the viewer can get the best stereoscopic visual experience within this distance.
2）Viewing angle and stereo effect:
The viewing angle will also affect the presentation of the stereo effect. Usually, the viewer needs to stay within a specific viewing angle to get the best stereo effect. This angle range depends on the specific design and parameters of the device.
Assuming that the viewing angle of the device is 30 degrees (15 degrees on each side), the viewer needs to watch within this angle range to get the best stereo effect.
II. Shooting distance limitation
In terms of shooting, 3d stereoscopic lenses also have distance limitations, which are mainly reflected in the distance between the subject and the lens (i.e., shooting distance).
1）Shooting distance range:
The shooting distance range of a 3d stereoscopic lens depends on the focal length, aperture, and other parameters of the lens. Generally speaking, the shooting distance needs to be within the focal length range of the lens, and the images received by the left and right eyes must be able to produce the best stereoscopic effect.
Assuming that the focal length of the lens is 50mm and the aperture is F2.8, the shooting distance may need to be between a few meters and tens of meters. The specific shooting distance needs to be adjusted according to the size of the subject, the distance from the lens, and the desired stereoscopic effect.
2）The relationship between lens spacing and shooting distance:
There is a certain relationship between lens spacing (that is, the distance between two cameras or lenses) and shooting distance. The larger the lens spacing, the richer the information on both sides of the object captured, and the stronger the sense of space. However, if the lens spacing is not set properly, it may lead to problems such as weakened stereoscopic effect or ghosting.
The specific mathematical formula is: the distance between the central axis of the two lenses = the distance from the subject to the camera/lens focal length (full frame). However, it should be noted that this formula applies to full-frame cameras and lenses, and corresponding conversion is required for non-full-frame cameras and lenses.
For example, if two identical cameras and lenses are used for 3D shooting, the focal length of the lens is 50mm (non-full-frame cameras need to be converted to equivalent focal length), and the distance from the subject to the camera is 10 meters, then the distance between the central axis of the two lenses should be set to 10 meters / 50mm (equivalent focal length after conversion) = 0.2 meters.
III. Other considerations
1）Lens selection and installation:
When selecting and installing a 3d stereoscopic lens, it is necessary to ensure the quality and installation accuracy of the lenses. The focal length, aperture, and other parameters of the lens need to be selected according to the shooting requirements.
When installing, it is necessary to ensure that the connection between the lens and the camera or display device is firm and reliable to avoid problems such as looseness or misalignment.
2）Ambient light control:
The brightness and angle of the ambient light will also affect the presentation of the 3D stereo effect. Therefore, when using a 3d stereoscopic lens, it is necessary to pay attention to the control of ambient light.
When viewing in a darker environment, it may be necessary to add lighting equipment to improve the brightness and clarity of the image; when viewing in an environment with too strong or too dark light, it may be necessary to adjust the brightness and contrast of the display to obtain the best viewing effect.
