Eyes even wider open

Sky at Night Magazine - - FIRST SIGHT -

Two im­por­tant at­tributes de­ter­mine your choice of eye­piece for a par­tic­u­lar ob­ser­va­tion: the fo­cal length and the ap­par­ent field of view (AFOV) in de­grees (°). The fo­cal length de­ter­mines the mag­ni­fi­ca­tion of a par­tic­u­lar tele­scope (mag­ni­fi­ca­tion = fo­cal length of tele­scope/fo­cal length of eye­piece) and the AFOV de­ter­mines the true field of view ob­served de­pend­ing on the mag­ni­fi­ca­tion (true field of view = AFOV/mag­ni­fi­ca­tion).

A stan­dard Plössl eye­piece, like those of­ten bun­dled with new tele­scopes, com­prises four lens el­e­ments and pro­duces an AFOV of around 52°. The Omegon Panorama IIs have be­tween seven and nine lens el­e­ments with a large eye lens al­low­ing for some clever op­ti­cal ma­nip­u­la­tion to nearly dou­ble that AFOV to 100°. As a re­sult, they pro­duce a re­ally wide true field of view.

As well as al­low­ing you to see more of a large ob­ject through the tele­scope, a re­ally wide field of view pro­vides a won­der­fully im­mer­sive ex­pe­ri­ence giv­ing you the feel­ing of be­ing part of the view you’re ob­serv­ing.

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