Gerd Neumann CTU-M48 Camera Tilting Unit
As modern CCD camera chips get larger and larger, it becomes more difficult to align them perfectly perpendicular to the optical axis and parallel to the focal plane. Often the sensor is not mounted accurately in the camera housing and this can result in uneven sharpness and focus from one side of the sensor to the other, even though it may appear that you have mounted the camera properly. Here is where the Neumann CTU will help!
The Neumann CTU allows you to adjust the tilt of the focal plane very easily and precisely. Similar units from other manufacturers have three pairs of push-pull screws at 120° and can be very difficult to adjust. Push/Pull screws are much too coarse and a lot of adjustment is done via elastic or even plastic deformation of the main body to achieve the required image plane movements.
In contrast, at the heart of the Neumann CTU are three radial screws with a very light cone shape formed at one end. By screwing these cones in, the two parts of the Neumann CTU are separated by a very small amount. A whole turn of a screw corresponds to a separation of only 0.2mm. Due to this fine movement and the large outer diameter of the Neumann CTU, it is quite easy to adjust the position of the sensor to less that 1/100mm.
Both sides of the Neumann CTU are held together with three very strong packs of disk springs and secured with set screws. These springs provide a very strong holding force and also keep everything together. The overall tightness of the Neumann CTU is very high so if you mount a camera with a weight of less than 3kg to the Neumann CTU, you will not have to tighten the set screws (two for each radial adjustment screw). For use with heavy imaging outfits we added the set screws to be on the safe side but it is unlikely that even heavy camera assemblies will need them but, should they be needed, only very slight tightened should be necessary.