The system is optimized specifically for f/10 Schmidt-Cassegrain telescopes to allow for correction of the field curvature and spherical chromatism that afflicts these types of instruments. At f/3.3, the maximum corrected field has a diameter of 9mm at the image plane which makes the unit suitable for CCD cameras with imaging chips of the same diagonal dimension or smaller.

With regards to color imaging, the NGM is was primarily optimized for the wavelengths of 450, 550, and 650 nm which are the centre wavelengths for the commonly used RGB system. Secondary weight was given to 850 nm light during the optimizing process. Thus, use of the NGM telecompressor with no filter except the violet light rejection filter, will give will corrected images using the full spectral sensitivity of the CCD. As in all refractive systems of this type, the violet wavelengths are the least corrected. As a result, a violet light rejection filter is supplied with the NGM which blocks all light with wavelengths shorter than 415 nm.

In order to achieve the proper 3 times reduction and the best correction, the back focus distance of 55mm (assuming 3 mm for the CCD window) must be maintained. Optec supplies various length adapters which match the NGM to a particular camera and thread. While other reductions are possible by varing the back focus distance, the best corrected image is obtained with the 55mm distance.