Initially the [[detector]] used in telescopes was the human [[eye]]. Later, the sensitized [[photographic plate]] took its place, and the [[spectrograph]] was introduced, allowing the gathering of spectral information. After the photographic plate, successive generations of [[electronic detector]]s, such as the [[charge-coupled device]] (CCDs), have been perfected, each with more sensitivity and resolution, and often with a wider wavelength coverage.
Teleskop kajian terkini ada banyak alat untuk dipilih seperti:
Current research telescopes have several instruments to choose from such as:
*imagers, of different spectral responses
*spectrographs, useful in different regions of the spectrum
*polarimeters, that detect light [[polarization]].
The phenomenon ofFenomenon optical [[diffraction]] sets a limitmemberikan tosebuah thehad resolutionke andkualiti imageresolusi qualitydan thatimej asebuah telescopeteleskop can achieve, which is the effective area of the [[Airy disc]], which limits how close two such discs can be placed. This absolute limit is called the [[diffraction limit]] (or sometimes the [[Rayleigh criterion]], [[Dawes limit]] or [[Sparrow's resolution limit]]). This limit depends on the wavelength of the studied light (so that the limit for red light comes much earlier than the limit for blue light) and on the [[diameter]] of the telescope mirror. This means that a telescope with a certain mirror diameter can resolve up to a certain limit at a certain wavelength. If greater resolution is needed at that wavelength, a wider mirror has to be built or [[aperture synthesis]] performed using an array of nearby telescopes.
