Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_terminator_challenge_winners.thumb.jpg.6becf44442bc7105be59da91b2bee295.jpg

Search the Community

Showing results for tags 'field of view'.



More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


Forums

  • Welcome
    • Welcome
  • Beginners
    • Getting Started General Help and Advice
    • Getting Started Equipment Help and Advice
    • Getting Started With Observing
    • Getting Started With Imaging
  • Community
    • Official SGL Announcements and Events
    • SGL Challenges and Competitions
    • SGL Star Parties
    • Star Parties & Astro Events
    • Celestial Events Heads Up
    • The Astro Lounge
  • Retailers
    • Sponsor Announcements and Offers
    • FLO Clearance Offers
    • Supplier Reviews
  • Astro Classifieds
    • For Sale / Swap
    • Wanted
  • Equipment
  • Observing
  • EEVA (Electronically Enhanced Visual Astronomy)
  • Imaging
  • Science
  • WADAS's WADAS Discussion Forum
  • Beaufort Club's Topics
  • Swindon Stargazers Club's Topics
  • East Midlands Stargazers''s Topics
  • Central Scotland Astro's Topics
  • SGL Cumbrian Skies's Topics
  • Herts, Beds and Bucks Group's Topics
  • SGL East Anglian Group's Topics
  • South Leicester Observers's Topics
  • South Wales Group's Topics
  • SGL Surrey Observers's Topics
  • South Yorkshire Stargazers's Topics
  • Yorkshire Astronomers's Topics
  • Devon and Cornwall's Topics
  • West Midlands's Topics
  • Essex Cloud Dodgers's Topics
  • Essex Cloud Dodgers's New equipment
  • NLO and Planetarium's Topics
  • Astronomical Society of Edinburgh's Discussion
  • Dorset Stargazers's Topics
  • Hairy Stars Club (Comets)'s Tutorials and Guides
  • Hairy Stars Club (Comets)'s General Discussion
  • Hairy Stars Club (Comets)'s Observing Campaigns
  • Hairy Stars Club (Comets)'s Analysis results
  • Hairy Stars Club (Comets)'s Useful Links
  • Pixinsight Users Club's Pixinsight Discussion Forum

Calendars

  • Astro TV
  • Celestial Events
  • SGL Calendar
  • Astro Society Events
  • Star Parties
  • WADAS's Events
  • Beaufort Club's Events
  • Astronomical Society of Edinburgh's Events
  • Dorset Stargazers's Events

Blogs

There are no results to display.

There are no results to display.


Find results in...

Find results that contain...


Date Created

  • Start

    End


Last Updated

  • Start

    End


Filter by number of...

Joined

  • Start

    End


Group


AIM


MSN


Website URL


ICQ


Yahoo


Jabber


Skype


Interests


Location

Found 3 results

  1. I Just bought a celestron astromaster 130EQ and I am still getting used to star hopping plus the red dot star pointer is a bit annoying. Will it be beneficial to invest in a 40mm eyepiece to make star hopping easier ? Will the larger field of view provided by the 40mm eyepiece be worthwhile ?
  2. Hi astropeeps Can anyone explain why the view through a 21mm celestron ultima duo eyepiece frames the moon perfectly, but when I attach the camera it acts more like a 18mm eyepiece and a third of the moon is out of frame? Do I need an extender of some sort or a better camera? I have a LUMIX G7, micro 4/3 mount. Cheers The Nut
  3. OK so just as I was writing my original and confused question I had a thought and think I might have worked it out. I've attached a drawing to try and show what I mean and help others if they're ever as confused as I was. I could only find sources that quoted brightness reduces four-fold for a two-fold increase in magnification, but I just couldn't wrap my head around and visualise it (too little mental exercise these days!!) - I knew it was something to do with the area of a circle but that's about it. Then I had a thought and made a little drawing: The blue circle represents what the telescope can see - for example it's maximum field of view (i.e. the most amount of sky it could ever possibly see: I worked out a theoretical 18.92 degrees for the SW200P - the second image shows how I came to this conclusion). The grey object (of no particular shape) in the middle of these blue circles is the same size because as far as the telescope is concerned the sky is the same scale (the scope still "see's" the same circle of sky). The red circle represents a lower power eyepiece's view and encircles a larger [field of view] area of the sky (the lower red circle show's what we'd see in the eyepiece: a smaller, brighter object) The green line represents a higher power eyepiece's view and encircles a narrower [field of view] area of the sky (the lower green circle show's what we'd see in the eyepiece: a larger, dimmer object) Am I right in thinking that the higher power eyepiece takes the light from a smaller [field of view] 'circle' in the sky than the lower power, but 'blows it up' to the same size in the eyepiece for us to see, as in the lower green and red circles? And if so is that what explains why the brightness goes down four-fold for a two-times magnification (because the light from a smaller [field of view] area is being shown at the same/similar size to the eye)? And essentially is this right: the scope always see's the same [field of view] 'circle' of the sky but the different eyepieces pick out different sized [field of view] 'circles' of this? Before I realised this I was under the delusional and confused impression that a smaller object in the sky might be brighter because the whole of the objective aperture could be used for that one object!!
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.