Image sensor alignment
The proper alignment of a camera sensor requires high levels of precision and very tight tolerances. Small deviations from the nominal values can significantly reduce the achievable image quality and hinder the user’s ability to take full advantage of their selected lens.
Sensor alignment errors can result in the following macroscopically observable issues.
Incorrect back-focal distance
A translation of the sensor along the Z axis could cause an incorrect back-focal distance. This results in a notable inability to properly focus the system. Due to the variation in the working distance of the optics, the overall system performance is reduced - this reduction in system performance can be observed as increases in chromatic aberration and/or distortion.
Vignetting on the corners of the image
A translation of the sensor along the X and Y axis could cause a vignetting on the corners of the image. Depending on the lens, it may be possible to notice changes in vignetting even with small movements of the sensor. The extent of this effect depends on the size of the image circle of the lens.
Image rotated with respect to the camera case
A Z-axis rotation of the sensor could cause an image rotated with respect to the camera case. This effect is of greater concern when using lenses that do not feature round image circles, like Opto Engineering’s TC CORE® series
Blurred image edges
A tilted sensor could cause a blurred image edges. The tilt of the sensor alters the focus plane that is conjugate to the sensor plane (Scheimpflug effect). For example, if the user focuses the lens to obtain image clarity at the center of the image then the edges of the image will appear blurry. The magnitude of this effect is inversely proportional to the depth of field of the system.
ITALA sensor alignment
In order to ensure that our cameras do not suffer from any of the aforementioned issues, all ITALA series cameras are tested to verify that the tilt and rotation of the sensor fall within the appropriate thresholds and meet our rigorous quality standards.