The Next Generation Palomar Spectrograph (NGPS) is a high-throughput medium-resolution broadband spectrograph  developed for the Hale telescope. It consists of four spectroscopic channels, where ultraviolet channel covers the region  [310-436] nm and delivers a resolving power about 4000 with 0.5 arcsec focal plane sampling at the center wavelength  370 nm. The spectrometer operates in the dome under wide temperature range from -10 degrees to 30 degrees, and  temperature variation is around 3 degrees per night. 
One of the goals of NGPS is to achieve excellent image quality and extremely high stability over a wide temperature  range. It is indeed a challenge due to limited selection of optical materials in the ultraviolet waveband. This article  introduces different camera concept for the ultraviolet channel of NGPS. The Schmidt reflective camera was finally  adopted after evaluation of their performance.