lamplight
Pooh-Bah
Reged: 09/18/12
Loc: west central MA, U.S.
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Re: zoom eyepiece and FOV
[Re: Jon Isaacs]
#5672108 - 02/10/13 10:35 AM
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As a noob, I'm seeing that almost every question I've ever asked has already been answered here 10,000 times. I don't know how you guys have the patience for it but I am very grateful. It's a very involved and multifaceted pursuit. So many things seem to keep coming up that you ok, I) had no idea was even an issue. S anyhow...
I'm trying to use the search button more often 
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dpwoos
Pooh-Bah
Reged: 10/18/06
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Re: zoom eyepiece and FOV
[Re: Jon Isaacs]
#5672109 - 02/10/13 10:35 AM
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If a PhD student doesn't know how to think and learn on their own then something is terribly wrong. On the other hand, most of the little kids I work with (and a lot of adults) don't know how, and actually seem to be uncomfortable with the activity (at least in math/logic). How does one get from the little kid to the PhD student? I don't think anyone really knows, but for sure somewhere in the trajectory to adulthood some folks learn how to think well, and others don't, and it seems to happen less often in the US then it does in many other countries.
Anybody can say "help me" without any thinking at all, whereas asking a question requires that some consideration/effort has gone into it. To me, there is a big difference and I don't believe anybody is being served by answering stuff like "Do I need an xxx". I would ask why they thought they might need an xxx, and if they don't have an answer then they don't need one. On the other hand, maybe a forum such as this serves a purpose other than acquiring/sharing info, and "help me", "do I need", etc. is an invitation to socialize as opposed to an actual request for assistance? Hmm - I will have to think about that.
BTW, I think the the o.p.'s question about zoom eyepieces and fov is a great one, which is why I answered in the first place.
Edited by dpwoos (02/10/13 10:40 AM)
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howard929
Member
Reged: 01/02/11
Loc: Low End of High Ground
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Re: zoom eyepiece and FOV
[Re: dpwoos]
#5672145 - 02/10/13 11:10 AM
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This isn't a vocation, it's a hobby. Most if not all who come to it are busy elsewhere in their lives with full time attention. Stealing away some that attention to learn the in's and out's of all of this from square one is a daunting task.
Leaning on others to answer the most basic of questions may not be your way for anyone to learn but when answered, it sure is appreciated. What's missing from your take on this is one never knows just when someone else reaches that Ah-Ha moment. When then say to themselves "How stupid I was. I get it." And I'd hate to think that it wouldn't happen to someone around here sooner rather then later because "help me" isn't allowed.
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dpwoos
Pooh-Bah
Reged: 10/18/06
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Re: zoom eyepiece and FOV
[Re: howard929]
#5672473 - 02/10/13 02:33 PM
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Quote:
What's missing from your take on this is one never knows just when someone else reaches that Ah-Ha moment. When then say to themselves "How stupid I was. I get it." And I'd hate to think that it wouldn't happen to someone around here sooner rather then later because "help me" isn't allowed.
Maybe, or maybe rewarding "help me" makes it happen later, if at all? Just to be clear, I'm not saying that anything is or isn't "allowed", but rather am suggesting that instead of everybody responding to these kinds of "help me" questions with their own opinions about what somebody else needs/wants/oughts, that folks instruct and prompt the questioner in ways that produce better, more knowledgable, and more directed questions. It takes some knowledge to ask a good question, and sometimes the best answer is not an answer at all but rather a suggestion on how to get to that more knowledgable place.
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Jon Isaacs
Postmaster
Reged: 06/16/04
Loc: San Diego and Boulevard, CA
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Re: zoom eyepiece and FOV
[Re: dpwoos]
#5672908 - 02/10/13 07:22 PM
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Quote:
Maybe, or maybe rewarding "help me" makes it happen later, if at all? Just to be clear, I'm not saying that anything is or isn't "allowed", but rather am suggesting that instead of everybody responding to these kinds of "help me" questions with their own opinions about what somebody else needs/wants/oughts, that folks instruct and prompt the questioner in ways that produce better, more knowledgable, and more directed questions.
You do it your way, I'll do it mine. I find the questions asked in this forum to be intelligent questions and deserving of answers. As I said, ideally, everyone has a knowledgeable friend to help them understand the concepts and show them the ropes. Unfortunately, most don't. My goal, and I think other more experienced astronomers who post here share this goal, is to be that friend.
Jon Isaacs
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panhard
It's All Good
Reged: 01/20/08
Loc: Markham Ontario Canada
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Re: zoom eyepiece and FOV
[Re: Jon Isaacs]
#5673193 - 02/10/13 10:20 PM
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+1 
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howard929
Member
Reged: 01/02/11
Loc: Low End of High Ground
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Re: zoom eyepiece and FOV
[Re: panhard]
#5673204 - 02/10/13 10:29 PM
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Obviously!
(mind if get in line here?) ...didn't think so.
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mike in arkansas
member
Reged: 01/26/13
Loc: Arkansas
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Re: zoom eyepiece and FOV
[Re: Jon Isaacs]
#5674052 - 02/11/13 01:18 PM
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Wow-- I think my questions(s) were answered. And I agree an astronomy club would be a wonderful resource -- if there was one closer than 100 miles away. I enjoy doing research on my own but sometimes it is wonderful to have resources like you you folks here at CN. (by the way-- what does o.p. mean?)
Mike
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dpwoos
Pooh-Bah
Reged: 10/18/06
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Re: zoom eyepiece and FOV
[Re: mike in arkansas]
#5674062 - 02/11/13 01:23 PM
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original poster, i.e. you. To bad about the astro club. Have you checked out if they have a dark site/observing site? If they do and you are lucky, it will be much closer to you than 100 miles and so maybe still a possible resource.
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mike in arkansas
member
Reged: 01/26/13
Loc: Arkansas
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Re: zoom eyepiece and FOV
[Re: dpwoos]
#5674184 - 02/11/13 02:53 PM
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OP of course!!
Well not sure if there is a dark site in conjunction with the little rock club, but I live on 40 acres in the ozarks and have a couple of meadows that are great for observing. 10 miles from the nearest lights (Mountain View - 3000 people). I am looking for any observers in the area who might be able to give some on hands assistance as my wife and I figure all this out!!
Mike
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dpwoos
Pooh-Bah
Reged: 10/18/06
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Re: zoom eyepiece and FOV
[Re: mike in arkansas]
#5674223 - 02/11/13 03:20 PM
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Wow - with a place like that I bet you will find folks to observe with, especially if you put out a pot of coffee!
What about this club:
http://nwastargazers.org/
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mike in arkansas
member
Reged: 01/26/13
Loc: Arkansas
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Re: zoom eyepiece and FOV
[Re: dpwoos]
#5678331 - 02/13/13 08:44 PM
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I am thinking about an ad in the paper --free since I subscribe- to see who might be interested! Last ep question-- what is the practical maximum mm length for a 1.25 ep -low power-? A dobsonian 6" 1200mm f8? I think I have settled on the TMB for shorter focal length.
Again thanks, mike
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mman22
journeyman
Reged: 01/05/13
Loc: Western Montana, USA
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Re: zoom eyepiece and FOV
[Re: mike in arkansas]
#5678372 - 02/13/13 09:17 PM
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Mike, sounds like we have had similar questions. You might want to check out my posts as some of the questions you may have will already be answered there. BTW, grew up not too far from you in SW Mo, you have some really good skies where you are at. Enjoy! Oh, I don't know for certain on the long f/l eps, but I have seen 40mm in the 1.25.
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kenrenard
scholastic sledgehammer
Reged: 12/13/12
Loc: Dunmore, PA
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Re: zoom eyepiece and FOV
[Re: mike in arkansas]
#5678377 - 02/13/13 09:20 PM
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Mike,
I think you will be happy with the TMB eyepiece I know I am.
I'll leave the practical maximum up to the more experienced folks. I generally use my 24mm for wide field viewing. I have a 2 inch 38mm q70 which is nice but can get soft on the edges. It doesn't bother me however, I can see where someone used to looking through premium eyepieces may be affected.
Ken
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dpwoos
Pooh-Bah
Reged: 10/18/06
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Re: zoom eyepiece and FOV
[Re: mike in arkansas]
#5678432 - 02/13/13 09:49 PM
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You can use any 1.25" eyepiece, though the usual low-power choice is a 32mm plossl (50 degree afov, 27mm field stop). Many folks consider, for example, the Televue 24mm Panoptic (68 degree afov, 27mm field stop) as a big step up, as it produces the same tfov as the plossl but at a higher magnification. Can you picture this? More magnification means that you see a smaller amount of sky, but the wider afov expands the view to match the plossl. Look at the pictures looking through an eyepiece on this page:
http://www.televue.com/engine/TV3b_page.asp?return=Advice&plain=TRUE&...
The second pair both show the same tfov, but the second one is higher magnification and higher afov - like the 32mm plossl and the 24mm panoptic.
It is hard to go wrong with a nice 32mm (or there abouts) plossl - mine gets a lot of work in my 6" f/8. I also get a lot of use from my 6mm TMB, which is a great high-power choice. What about medium power?
Edited by dpwoos (02/14/13 08:58 AM)
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kansas skies
sage
Reged: 12/02/12
Loc: Kansas, USA
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Re: zoom eyepiece and FOV
[Re: dpwoos]
#5678579 - 02/13/13 11:27 PM
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I had the opportunity recently to borrow a friend's 8-24mm zoom eyepiece. My experience with it was just as was described by Jon Isaacs. The apparent field of view was considerably larger at the higher magnification. I personally found this to be a little disconcerting. The quality of the lens was decent, but I definitely came away with the impression that I was forced to compromise, both in apparent field of view and overall quality as compared to that offered by a collection of individual eyepieces.
Bill
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