The tilt scanned solid etalon interferometer has very real advantages in resolving power, throughput and sensitivity over other direct detection techniques, particularly for atmospheric and astronomic spectroscopic measurements. This includes many situations where the measuring instrument is detector-noise limited. These advantages can be exploited in a physically compact, stable, electro-optical system, which imposes no severe tolerances on mechanical mounting, optical alignment or angular scan control. Materials and optical fabrication techniques are available at least for the range 1 to 15 µm which allows for etalon bandwidths of ⪅ 0.2 cm-1, finesse of 50, and peak transmission of 65%. The etalon can be fine scanned over a free spectral range (≈ 10 cm-1) at discrete points in its channel transmission spectrum, or over many hundreds of free spectral ranges, depending on the blocking mode. Some practical aspects of the design, evaluation and use of solid etalons in conventional optical systems are discussed, and the characteristics of a number of such etalons fabricated within the past two years are presented.