Page 4 of 4 FirstFirst ... 234
Results 31 to 40 of 40
Like Tree23Likes

Thread: Strategy for eye piece purchases

  1. #31
    Eskil's Avatar
    Eskil is offline White Dwarf
    Points: 1,478, Level: 22
    Level completed: 78%, Points required for next Level: 22
    Overall activity: 2.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!365 Days+ Registered Achievement!
    Join Date
    May 2017
    Location
    Lund, Sweden
    Posts
    44
    Points
    1,478
    Level
    22
    Thanks
    9
    Thanked 2x 2 Posts

    Default Re: Strategy for eye piece purchases



    Quote Originally Posted by Ozman13 View Post
    The ES 24mm 68 is 1.25" and will give you the widest possible view in your scope and is clear to the edge. That is the EP I would get.
    You are quite right. I had forgotten I had made that realisation once..

    /Eskil

  2. #32
    Bigzmey's Avatar
    Bigzmey is offline HYPER GIANT
    Points: 40,753, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 59.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!200+ Posts Achievement!
    Join Date
    Sep 2015
    Location
    Planet Earth
    Posts
    7,548
    Points
    40,753
    Level
    100
    Thanks
    1,801
    Thanked 3,186x 2,292 Posts

    Default Re: Strategy for eye piece purchases

    Quote Originally Posted by Eskil View Post
    You are quite right. I had forgotten I had made that realisation once..

    /Eskil
    18mm 82 degree, 24mm 68 degree and 32mm 50 degree EPs will deliver similar, close to max or max AFV in your scope. The only difference will be magnification and exit pupil. I would play first with Meade 5000 18mm UWA and see if you even need 24mm or 32mm EPs
    Ozman13 likes this.

  3. #33
    Eskil's Avatar
    Eskil is offline White Dwarf
    Points: 1,478, Level: 22
    Level completed: 78%, Points required for next Level: 22
    Overall activity: 2.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!365 Days+ Registered Achievement!
    Join Date
    May 2017
    Location
    Lund, Sweden
    Posts
    44
    Points
    1,478
    Level
    22
    Thanks
    9
    Thanked 2x 2 Posts

    Default Re: Strategy for eye piece purchases

    Quote Originally Posted by Bigzmey View Post
    18mm 82 degree, 24mm 68 degree and 32mm 50 degree EPs will deliver similar, close to max or max AFV in your scope. The only difference will be magnification and exit pupil. I would play first with Meade 5000 18mm UWA and see if you even need 24mm or 32mm EPs
    Indeed, budget at the moment is seriously overrun anyways so no new eye pieces either way until Christmas or a substantial sale..

  4. #34
    Eskil's Avatar
    Eskil is offline White Dwarf
    Points: 1,478, Level: 22
    Level completed: 78%, Points required for next Level: 22
    Overall activity: 2.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!365 Days+ Registered Achievement!
    Join Date
    May 2017
    Location
    Lund, Sweden
    Posts
    44
    Points
    1,478
    Level
    22
    Thanks
    9
    Thanked 2x 2 Posts

    Default Re: Strategy for eye piece purchases

    Quote Originally Posted by Bigzmey View Post
    18mm 82 degree, 24mm 68 degree and 32mm 50 degree EPs will deliver similar, close to max or max AFV in your scope. The only difference will be magnification and exit pupil. I would play first with Meade 5000 18mm UWA and see if you even need 24mm or 32mm EPs

    Is there any other difference apart from a small difference in AFOV between the 18mm 82° and the 32mm 50°? Will the 32mm show fainter objects like galaxies better (with better contrast but smaller) or will this be the same in both eye pieces?

    /Eskil

  5. #35
    Bigzmey's Avatar
    Bigzmey is offline HYPER GIANT
    Points: 40,753, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 59.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!200+ Posts Achievement!
    Join Date
    Sep 2015
    Location
    Planet Earth
    Posts
    7,548
    Points
    40,753
    Level
    100
    Thanks
    1,801
    Thanked 3,186x 2,292 Posts

    Default Re: Strategy for eye piece purchases

    Quote Originally Posted by Eskil View Post
    Is there any other difference apart from a small difference in AFOV between the 18mm 82° and the 32mm 50°? Will the 32mm show fainter objects like galaxies better (with better contrast but smaller) or will this be the same in both eye pieces?

    /Eskil
    If you observe under very dark sky, increasing exit pupil and decreasing magnification indeed would help to improve the contrast for large dim targets. If you observe from light polluted location, sky background will also become brighter when you increase exit pupil to the point when it becomes non-productive.

    From where I observe I don't benefit going above 4-5mm exit pupil, which would correspond to 20-25mm EP for F5 scope. This is why I suggest to try 18mm first. With 3.6mm exit pupil and close to max AFV it should work great on large dim DSOs and as scouting EP for smaller galaxies. You may not need 24mm or 32mm EPs.
    Ozman13 likes this.

  6. #36
    Eskil's Avatar
    Eskil is offline White Dwarf
    Points: 1,478, Level: 22
    Level completed: 78%, Points required for next Level: 22
    Overall activity: 2.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!365 Days+ Registered Achievement!
    Join Date
    May 2017
    Location
    Lund, Sweden
    Posts
    44
    Points
    1,478
    Level
    22
    Thanks
    9
    Thanked 2x 2 Posts

    Default Re: Strategy for eye piece purchases

    Quote Originally Posted by Bigzmey View Post
    If you observe under very dark sky, increasing exit pupil and decreasing magnification indeed would help to improve the contrast for large dim targets. If you observe from light polluted location, sky background will also become brighter when you increase exit pupil to the point when it becomes non-productive.

    From where I observe I don't benefit going above 4-5mm exit pupil, which would correspond to 20-25mm EP for F5 scope. This is why I suggest to try 18mm first. With 3.6mm exit pupil and close to max AFV it should work great on large dim DSOs and as scouting EP for smaller galaxies. You may not need 24mm or 32mm EPs.
    Thanks for the clarification. We will see what happens when I get to try the 18mm then. At the moment I have had 7 out of 8 eight nights completely cloudy so it feels like I am due some fine weather when it arrives later in the week..

  7. #37
    Eskil's Avatar
    Eskil is offline White Dwarf
    Points: 1,478, Level: 22
    Level completed: 78%, Points required for next Level: 22
    Overall activity: 2.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!365 Days+ Registered Achievement!
    Join Date
    May 2017
    Location
    Lund, Sweden
    Posts
    44
    Points
    1,478
    Level
    22
    Thanks
    9
    Thanked 2x 2 Posts

    Default Re: Strategy for eye piece purchases

    Quote Originally Posted by Ozman13 View Post
    It does deliver a wide field of view, but only the very central portion will be clear. Most of the wide field of view will show serious distortions and be totally out of focus getting worse as you move from the central portion. It is better to have a narrower EP that is clear to the edge than a wide EP that is only clear in the center. You get more observable area with the narrower EP. The ES EPs are clear to the edge in a fast scope and are the best value.
    Just out of curiosity I contacted Baader's support and asked them about the eye piece and got a pleasantly honest answer from them

    -----

    Hello!

    I would not recommend this eyepiece for your telescope - the 1,25"-adapter moves the eyepiece quite a distance away from the focuser; I'm not even sure if you can reach focus with it at all.

    Also, the field curvature is a problem - it is different for Newtonians and lens telescopes, and the Aspheric is not designed for fast Newtonians. There are other eyepieces made for fast Newtons, or you combine it with a coma corrector like the MPCC - but this would require a 2"-focuser, so it is no option for your telescope. I'm sorry - f/6 would be no problem, f/4 is a problem, and f/5 is in the critical region.

    -----

    Guess if the manufacturer is sceptic it would be a really bad decision to actually bad it for this scope.. Maybe next scope..
    Ozman13 and Bigzmey like this.

  8. #38
    Bigzmey's Avatar
    Bigzmey is offline HYPER GIANT
    Points: 40,753, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 59.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!200+ Posts Achievement!
    Join Date
    Sep 2015
    Location
    Planet Earth
    Posts
    7,548
    Points
    40,753
    Level
    100
    Thanks
    1,801
    Thanked 3,186x 2,292 Posts

    Default Re: Strategy for eye piece purchases

    Quote Originally Posted by Eskil View Post
    Just out of curiosity I contacted Baader's support and asked them about the eye piece and got a pleasantly honest answer from them

    -----

    Hello!

    I would not recommend this eyepiece for your telescope - the 1,25"-adapter moves the eyepiece quite a distance away from the focuser; I'm not even sure if you can reach focus with it at all.

    Also, the field curvature is a problem - it is different for Newtonians and lens telescopes, and the Aspheric is not designed for fast Newtonians. There are other eyepieces made for fast Newtons, or you combine it with a coma corrector like the MPCC - but this would require a 2"-focuser, so it is no option for your telescope. I'm sorry - f/6 would be no problem, f/4 is a problem, and f/5 is in the critical region.

    -----

    Guess if the manufacturer is sceptic it would be a really bad decision to actually bad it for this scope.. Maybe next scope..
    Nothing "bad" about it: you much EP to your scope. Baader Aspheric are ones of my most favorite EPs, but I use them in F10 8" SCT and F7.5 5" APO refractor and with 2" focuser. Even in my F5 achro refractor 31mm is not that bad, but it gives 6mm exit pupil there and background sky is too bright to be useful.

    Fast reflectors are really picky about EP quality, you need to use well corrected EPs for them.
    Ozman13 likes this.

  9. #39
    Ozman13's Avatar
    Ozman13 is offline HYPER GIANT
    Points: 29,191, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 62.0%
    Achievements:
    2 Posts Achievement5 Threads Achievement!20 Posts Achievement!365 Days+ Registered Achievement!50 Posts Achievement!
    Join Date
    Jun 2013
    Location
    Hopkinsville Kentucky
    Posts
    8,431
    Points
    29,191
    Level
    100
    Thanks
    170
    Thanked 2,237x 2,010 Posts

    Default Re: Strategy for eye piece purchases

    Quote Originally Posted by Bigzmey View Post
    Nothing "bad" about it: you much EP to your scope. Baader Aspheric are ones of my most favorite EPs, but I use them in F10 8" SCT and F7.5 5" APO refractor and with 2" focuser. Even in my F5 achro refractor 31mm is not that bad, but it gives 6mm exit pupil there and background sky is too bright to be useful.

    Fast reflectors are really picky about EP quality, you need to use well corrected EPs for them.
    My experience as well, the Hyperions and Aspheric EPs I had worked well for me in the older SCT I had at the time. When I started getting faster scopes, I could see the degradation begin. When I got the larger Dob, I started to replace the Baader's with the ESs.
    Bigzmey likes this.

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    ACF 8"SCT,
    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.
    120, ES 102CF Apo triplet, ES AR102, ST100, ST90, Apex 90mm Mak, ST80, ETX60,
    Oberwerk BT-82XL-ED, 25x100s, 15x70s, 8x56s, Kasai 2.3x40s, Celestron AVX, CG4, SLT, LCM, Obie HD Parallel Bino mount
    Explore Scientific 82 degree and 68 degree EPs, Baader 9mm Ortho, Meade 5000 SWA EP set, many more various EPs, Baader
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    &SkyGlow, FringeKiller, SemiApo filters, Celestron UHC, Meade 4000 Nebular Filter, Kson OIII, DGM NPB and lots of astro stuff.

  10. #40
    Eskil's Avatar
    Eskil is offline White Dwarf
    Points: 1,478, Level: 22
    Level completed: 78%, Points required for next Level: 22
    Overall activity: 2.0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!365 Days+ Registered Achievement!
    Join Date
    May 2017
    Location
    Lund, Sweden
    Posts
    44
    Points
    1,478
    Level
    22
    Thanks
    9
    Thanked 2x 2 Posts

    Default Re: Strategy for eye piece purchases

    Quote Originally Posted by Bigzmey View Post
    Nothing "bad" about it: you much EP to your scope. Baader Aspheric are ones of my most favorite EPs, but I use them in F10 8" SCT and F7.5 5" APO refractor and with 2" focuser. Even in my F5 achro refractor 31mm is not that bad, but it gives 6mm exit pupil there and background sky is too bright to be useful.

    Fast reflectors are really picky about EP quality, you need to use well corrected EPs for them.
    Bad choice of words probably. Was a bit in a hurry and the post doesn't make sense even to me when I read it now..

    Unsuitable for my scope was what I meant to say. But I got a good impression of Baader as a company as they clearly communicated this to me.

    /Eskil
    Bigzmey likes this.

 

 
Page 4 of 4 FirstFirst ... 234

Similar Threads

  1. Strategy For Beginners
    By rnorman3 in forum Astronomy Beginners Forum
    Replies: 29
    Last Post: 12-31-2014, 04:48 PM
  2. Sanity check for purchases (and not purchases), please
    By dmitchast in forum Astronomy Beginners Forum
    Replies: 7
    Last Post: 09-14-2013, 10:43 PM
  3. Poor Seeing strategy
    By John Banister in forum Amateur Astronomy Forum
    Replies: 5
    Last Post: 04-24-2011, 04:23 PM
  4. Strategy Games
    By admin in forum Off Topic Forum
    Replies: 11
    Last Post: 05-11-2010, 08:15 PM
  5. RNC Strategy At Work...
    By Perseid in forum Amateur Astronomy Forum
    Replies: 44
    Last Post: 12-01-2006, 02:48 AM

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 02:24 PM.