Isihlongamkhathi

Isihlongamkhathi (noma isibonakude) siyisiklamo esisetshenziselwa ukupopola izinto ezikude ngokuhlonga ukuphafuka kwazo, ukumunyunga kwazo noma ukukhwentuza kwazo imiyonzi yenzubawonga. Ngokwendabuko, sasiyinsiza yokukhanya esebenzisa izififiyela (lenses), izibuko ezibhenile, noma inhlanganisela yakho kokubili ngenhloso yokubona izinto ezikude – kuyisibonakude sokukhanya. Namuhla, lesi siklamo sesikwazi ukuhlonga izingxenye ezihlukene zomungco wenzubawonga.

Izihlongamkhathi zokuqala ezaziwayo ezisebenzayo kwakuyilezo ezigwincizayo (refracting) ezazi fakelwe izififiyela zenhlaka futhi ezaziqanjwe kwelamaDashi ekuqaleni kwekhulu le-17. Zazisetshenziselwa kokubili ukuBona ezweni nokubona emkhathini.

Isihlongamkhathi esikhwentuzayo, esisebenzisa izibuko ukuze siqoqe futhi sihlozinge ukukhanya, saqanjwa iminyaka eyishumi ingakapheli kuqanjwe esigwincizayo.

Ekhulwini lama-20, kuye kwaqanjwa izihlongamkhathi ezintsha ezinhlobonhlobo, ezihlanganisa isihlongamkhathi somsakazo (1939's) nesihlongamkhathi sensibomvu (1960's).

uMsukagama
Ibizo elithi isihlongamkhathi liyinhlanganisela yamabizo amabili, 'isihlonga' (elithathwe esenzweni ukuhlonga) + 'umkhathi' (elisho indawo ezungezile efinyelela kude). Elithi isibonakude lona lilingisa elesingisi elithi telescope elimsuka wolimi lwesiGreki sasendulo ochazwa kanje:  isiGriki τῆλε, (tele: 'kude') + σκοπεῖν, (skopein: 'ukubona'); uma lihlangene τηλεσκόπος, teleskopos 'ukubona kude', uma ngesiZulu kufakwa isiqalo 'isi' lisho ukuthi isibonakude.
Womabili lamabizo ayafaneleka njengoba adlulisa umqondo womsebenzi walesi siklamo.

Umlando

Irekhodi lokuqala elikhona lesibonakude kwakuyilungelo lobunikazi elaliyi-1608 elethwe kuhulumeni waseNetherlands ngumenzi wemibukiso waseMiddelburg uHans Lippershey for a telescope refracting. UGalileo wezwa ngakho futhi, ngo-1609, wazakhela eyakhe inguqulo, futhi wenza umbono wakhe ngeteleskopu wezinto zasezulwini