Bo Lindberg, Luc Rouppe van der Voort, Jaime de la Cruz Rodriguez

The development of instrumentation for the European Solar Telescope (EST) benefits strongly from on-going development and use of similar instrumentation on previously built European solar telescopes. Here, we discuss the design and performance of CRISP and CHROMIS, which are the most scientifically productive instruments at the Swedish 1-m Solar Telescope. These are of high relevance to the development of the Tunable Imager Spectrometers (TISs), which will be functionally similar to CRISP and are expected to be the most highly requested first-generation instruments at EST. We showcase sample data and demonstrate the superior image quality of CRISP and CHROMIS. We describe their compact design without folding mirrors, which delivers high transmission, ease of alignment, and relatively low design and construction cost. We finally demonstrate that a similar design most likely can be implemented at EST but refer to a separate presentation describing the details of such TIS designs.