Results 1 to 8 of 8
  1. #1
    BoerneLBS's Avatar
    BoerneLBS is offline Junior Member
    Points: 6,616, Level: 56
    Level completed: 33%, Points required for next Level: 134
    Overall activity: 0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!2 Posts Achievement1000 Days+ Registered Achievement!
    Join Date
    Dec 2009
    Location
    Boerne, TX
    Posts
    5
    Points
    6,616
    Level
    56
    Thanks
    2
    Thanked 1 Time in 1 Post

    Default Purpose of a low-power eyepiece?



    okay, first of all, the disclaimer:

    New guy alert! New guy alert!

    There. Now, I've been reading the sticky threads in the eyepiece forum (HUGE help by the way) and I finally get it. Based on what I've read, I've got another one picked out to add to the two that came with my scope.

    While I was shopping though, I noticed the huge prices on low-power (say up to 40mm) eyepieces. The high price makes perfect sense based on the bigger elements, but I guess I'm stumped on what you'd use it for.

    For my scope, it would be: Focal length 1200 / 40 = 30x magnification.

    So at that low power, what exactly would you be looking at? Is it just for super-clear moon viewing only or something? General observation of the Milky Way?

  2. #2
    WWPierre's Avatar
    WWPierre is offline HYPER GIANT
    Points: 64,445, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    10 Days registered3 Years + Achievement400+ Posts AchievementGhost Achievement! Averaging 5+ posts a day!1000 Days+ Registered Achievement!
    Join Date
    Jun 2009
    Location
    Squamish B.C.
    Posts
    6,948
    Points
    64,445
    Level
    100
    Thanks
    1,095
    Thanked 2,953x 1,808 Posts

    Default

    It is the first eyepiece you use to find stuff. It is always nice to have an eyepiece that gives your scope it's lowest magnification. My most expensive eyepiece, (Siebert 30mm Ultra) gives me 21.66X, and was purchased for use as my "finder" eyepiece, and so I could see the Pleiades in their glorious entirety. There are lots of large groups of stars that are best viewed at low mags, and lots of DSOs that are big. Andromeda, for instance is more than twice as big as the moon. Then there is just random viewing of the Milky Way starfields.
    Meade 16" LightBridge; Celestron G-8N Bird-Jones/motorized EQ5;
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    127 Mak/go-to EQ5; Burgess 127f8 refractor; Sky-Watcher 5" F/5 collapsible dob; 90mm Mak/motorized EQ2; Royal Astro 76/910-GEM; Meade 60x700 refractor/alt/az; Zhumell 25x100 Coin Ops; GalilleoScope. Celestron 8mm-24mm zoom; lots of fixed EPs,some good, some..not so much. A small collection of surveying instruments; a forest of tripods; Canon Rebel Xti. Confirmed gadget junkie; Custodian of the Magnetic North Pole (Send $1.00 to Pierre each time you use a compass.)
    49-41-37.03N 123-09-29.61W Calculated magnetic declination: 17° 39' East

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.


    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.


    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

    We have been broadcasting our presence to the Universe for 100 years now. If there is a detachment of Galactic Pest Control within 100 light years, they are already on the way.

  3. The Following 2 Users Say Thank You to WWPierre For This Useful Post:

    EJMaine (01-16-2010),pe51c (01-17-2010)

  4. #3
    AustinPSD's Avatar
    AustinPSD is offline Super Moderator
    Points: 56,828, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 2.0%
    Achievements:
    200+ Posts Achievement!First 1000 Experience PointsGot three Friends20+ Friends Achievement!5+ Referrals Achievement!
    Join Date
    Sep 2009
    Location
    McDonald Observatory, Mt. Locke
    Posts
    6,921
    Points
    56,828
    Level
    100
    Thanks
    743
    Thanked 5,863x 3,113 Posts
    Blog Entries
    1

    Default

    In addition to serving as an aid in object location/targeting, for some objects, i.e. certain DSO's a lower power eyepiece provides a higher brightness and contrast level.
    CGEM 800 HD, NexGuide,
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    XT8 Limited Edition, Oberwerk BT-100, Canon 20D/20Da/T3i/60D/5D Mk III, various eyepieces, adapters, geegaws, widgets, and tiddlybits

  5. The Following User Says Thank You to AustinPSD For This Useful Post:

    pe51c (01-17-2010)

  6. #4
    Inkie's Avatar
    Inkie is offline Main Sequence
    Points: 6,812, Level: 57
    Level completed: 31%, Points required for next Level: 138
    Overall activity: 0%
    Achievements:
    10 Days registered365 Days+ Registered Achievement!First 1000 Experience Points750 Days+ Registered Achievement!1000 Days+ Registered Achievement!
    Join Date
    Dec 2009
    Location
    British Columbia, Canada
    Posts
    77
    Points
    6,812
    Level
    57
    Thanks
    0
    Thanked 36x 25 Posts

    Default

    I use such a large eyepiece for target acquisition and centering, but also to enjoy that particular view. It is, after all, a view in its own right, and magnified many times over what you can see with the unaided eye.

    Open clusters, globular clusters, galaxies, the juxtaposition of the Jovian moons,...all of these are afforded very pleasing views in eyepieces upwards of 40 mm. I have an Ultima 60 mm, a big black cannon, that gives one the impression of flying through space. Quite impressive. Unfortunately, its extreme exit pupil places it essentially on the shelf for me, now 20 years into its tenure in my stable of useful eyepieces. I am nearing 60, and my pupils simply no longer dilate sufficiently to enjoy the full unvignetted views that this marvellous ocular affords the typical user.

    -Crandell

  7. The Following User Says Thank You to Inkie For This Useful Post:

    pe51c (01-17-2010)

  8. #5
    Bob327's Avatar
    Bob327 is offline HYPER GIANT
    Points: 41,366, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 0%
    Achievements:
    10 Days registered200+ Posts Achievement!First 1000 Experience PointsGot three Friends365 Days+ Registered Achievement!
    Join Date
    Sep 2009
    Location
    Frederick Maryland
    Posts
    9,247
    Points
    41,366
    Level
    100
    Thanks
    19
    Thanked 4,039x 3,068 Posts

    Default

    I own a 30 and 40 mm Pentax XWs' and have a 35 mm Panoptic that actually get MUCH more use in my scopes then the higher powered eyepieces I have...

    More light gets to my eye, and I NEED that light for viewing extremely dim DSO's...which is what I enjoy looking at the most...

    Bob G.
    CPC1100 housed in a slotted domed observatory (Exploradome) 4 and 5 inch refractors for use from the lawn, a 8" Sct (NS 8i) for star parties...
    I Hate the winter so I use heated Motorcycle clothing to stay warm while observing in winter
    Retired, also have 2 other hobbies
    1. tinker with older Corvettes (6 in garage)
    2. make a heck of a lot of sawdust in my wood shop.

  9. The Following User Says Thank You to Bob327 For This Useful Post:

    pe51c (01-17-2010)

  10. #6
    ebusinesstutor's Avatar
    ebusinesstutor is offline Bright Giants
    Points: 8,910, Level: 65
    Level completed: 54%, Points required for next Level: 140
    Overall activity: 0%
    Achievements:
    10 Days registered200+ Posts Achievement!365 Days+ Registered Achievement!First 1000 Experience Points750 Days+ Registered Achievement!
    Join Date
    Jul 2009
    Location
    Canada
    Posts
    310
    Points
    8,910
    Level
    65
    Thanks
    126
    Thanked 159x 80 Posts

    Default

    My low power eyepiece is a 2" Siebert Observatory 36mm which gives me a 33x magnification in my 8" dob.

    It is the first eyepiece I use for finding objects. They are much easier to find in it's wide field of view.

    Like Pierre, I find large objects like the Pleiades and Andromeda Galaxy look great though it.

    It is also nice to see objects framed with the rich star field around them rather than just seeing the object itself.
    Garland Coulson
    --------------------
    President, Nanaimo Astronomy Society
    http://NanaimoAstronomy.com

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    XT8i dob
    Hyperion 8-24mm Click Zoom

  11. The Following User Says Thank You to ebusinesstutor For This Useful Post:

    pe51c (01-17-2010)

  12. #7
    BoerneLBS's Avatar
    BoerneLBS is offline Junior Member
    Points: 6,616, Level: 56
    Level completed: 33%, Points required for next Level: 134
    Overall activity: 0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!750 Days+ Registered Achievement!2 Posts Achievement1000 Days+ Registered Achievement!
    Join Date
    Dec 2009
    Location
    Boerne, TX
    Posts
    5
    Points
    6,616
    Level
    56
    Thanks
    2
    Thanked 1 Time in 1 Post

    Default

    Aha! See, I knew I liked this place for a reason. I have a separate finder scope (Orion 8XTi) but of course a low power eyepiece on the scope itself would probably se a ton sharper than just the finder, huh?

    I've only had 1 night of viewing since I got it- too cloudy or cold.

    I think it will be nice tomorrow night. I'll try to find Andromeda. Thanks for the answers!

  13. #8
    MarkM's Avatar
    MarkM is offline Photon Finder
    Points: 15,475, Level: 85
    Level completed: 79%, Points required for next Level: 75
    Overall activity: 0%
    Achievements:
    First 1000 Experience Points365 Days+ Registered Achievement!200+ Posts Achievement!100+ Threads Achievement!Got three Friends
    Join Date
    Mar 2009
    Location
    Austin, TX
    Posts
    1,129
    Points
    15,475
    Level
    85
    Thanks
    432
    Thanked 512x 285 Posts

    Default

    Quote Originally Posted by BoerneLBS View Post
    Aha! See, I knew I liked this place for a reason. I have a separate finder scope (Orion 8XTi) but of course a low power eyepiece on the scope itself would probably se a ton sharper than just the finder, huh?
    Not necessarily. That is a good RACI that comes with that scope and its 5 degree field of view is REALLY nice when it comes to star hopping to your target (which you need to do with an XT8i for really faint NGC and IC galaxies, most double stars , the PK planetary nebulae, etc.). It is also very nice to have a correct image view while before entering upside world in the Newt. The RACI that came with my XT8i is now permanently installed on my 15" reflector--cant imagine observing without it (or its neighboring Telrad)

    So look at the low power EP as the next step after using the RACI. As others have stated, maybe you want a nice wide view of the object or just want to use it to zero in on your target before upping the magnification.

    Yep, tomorrow night might be good for us here in Central, TX--hope so.
    Last edited by MarkM; 01-16-2010 at 12:49 AM.
    Location: 30° 19' N; 97° 54' W; elev 248 meters; yellow/green zone; NELM 5.7
    Instruments: Obsession 15" Dob; Orion XT8i; 2" refractor (Galileoscope); Televue EP arsenal; Bushnell 7X50 binos
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  14. The Following User Says Thank You to MarkM For This Useful Post:

    BoerneLBS (01-16-2010)

 

 

Similar Threads

  1. Low power 2" eyepiece
    By GWING in forum Telescope Eyepieces Forum
    Replies: 25
    Last Post: 03-05-2011, 12:39 PM
  2. Barlow or High Power Eyepiece?
    By Chris Schementi in forum Telescope Eyepieces Forum
    Replies: 3
    Last Post: 09-13-2009, 06:09 PM
  3. 2 inch Low-power eyepiece candy
    By guid0 in forum Amateur Astronomy Forum
    Replies: 36
    Last Post: 11-28-2003, 05:16 PM
  4. Max power eyepiece for a 4.5" Dobson?
    By or10n in forum Amateur Astronomy Forum
    Replies: 8
    Last Post: 09-21-2003, 02:37 PM
  5. What power eyepiece do you use for ???
    By Indianaradio in forum Amateur Astronomy Forum
    Replies: 1
    Last Post: 08-14-2003, 05:18 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBulletin® Version 4.2.0
Powered by vBulletin®
All times are GMT. The time now is 11:50 AM.