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Emmanuele Sordini, unless otherwise noted. All rights reserved.
Contents may not be reproduced, published, copied or transmitted in any form, including electronically, without written permission of the author.

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Emmanuele Sordini, se non diversamente specificato. Tutti i diritti riservati.
I contenuti non possono essere riprodotti, pubblicati, copiati o trasmessi sotto alcuna forma, incluso per via elettronica, senza il permesso scritto dell\'autore.

Tag : measuring the focal length of a telescope

Calculating the actual f/ ratio of a picture

Every telescope or telephoto lens has its “magic” f/number: that is, the ratio between its focal length and aperture. Although we don’t go deeper into the matter as it’s not within the scope of this article, it’s worth mentioning that the higher the f/ratio, the longer the exposure time required to yield a given picture density (i.e. how much detail we want to record). Each telephoto lens is normally used with the camera body it was built for, so that […]

By Emmanuele Sordini Astronomy: tips & tricks 18 June 2007 0

These photographs, text and web page designs are © Copyright 1997 - 2024
Emmanuele Sordini, unless otherwise noted. All rights reserved.
Contents may not be reproduced, published, copied or transmitted in any form, including electronically, without written permission of the author.
Tutti i contenuti (fotografie, testi e design del sito) © Copyright 1997 - 2023
Emmanuele Sordini, se non diversamente specificato. Tutti i diritti riservati.
I contenuti non possono essere riprodotti, pubblicati, copiati o trasmessi sotto alcuna forma, incluso per via elettronica, senza il permesso scritto dell'autore.