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The Perfect Number of Eypieces?

Paul73

By Paul73
in Discussions - Eyepieces

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niallk

niallk

Posted
Posted

My main "night" set has 4 eps + powermate 2.5x: Panoptic 24, Nagler 13mm, Nagler 7mm

Snap!!

I also have a pair of TV 15mm's for binoviewing on planets, and haven't bought an EP for 1.5yrs... Mind you I'd love a look through a 21mm Ethos and a 10mm Delos ;)

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estwing

estwing

Posted
Posted

Snap!!

I also have a pair of TV 15mm's for binoviewing on planets, and haven't bought an EP for 1.5yrs... Mind you I'd love a look through a 21mm Ethos and a 10mm Delos ;)

no you don't....look what happens when you do....and I always get the blame!!http://stargazerslounge.com/topic/228371-the-night-the-terminagler-was-terminated/

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Piero

Piero

Posted
Posted

Snap!!

I also have a pair of TV 15mm's for binoviewing on planets, and haven't bought an EP for 1.5yrs... Mind you I'd love a look through a 21mm Ethos and a 10mm Delos ;)

:smiley: it seems we have similar tastes!  :grin: Interesting to see that you prefer 1.25" with your 10" and 15"monsters! 

no you don't....look what happens when you do....and I always get the blame!!http://stargazerslounge.com/topic/228371-the-night-the-terminagler-was-terminated/

WOW! THAT IS A SCARY THREAD!  :eek:  :eek:

Thanks for the warning! But saying so, you make people wonder even more how the view through an E21 is!  :grin:

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niallk

niallk

Posted
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no you don't....look what happens when you do....and I always get the blame!!http://stargazerslounge.com/topic/228371-the-night-the-terminagler-was-terminated/

That is a dangerously good post in that link!

Dangerous in terms of the irreparable damage it could do to a person's bank account... a warning should pop up before you are allowed to read on :)

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Moonshane

Moonshane

Posted
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Excellent recognition Shane - I saw them just the once, supporting the Buzzcocks at Oxford New Theatre, autumn 1979.

as my daughters would say, I'm well jell - although thankfully it's in my youngest's genes though - only 18 but seeing PIL tomorrow and Happy Mondays next month!

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Dude_with_the_tube

Dude_with_the_tube

Posted
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dont do minimalist sets here :)

at one stage i had 40 eye pieces,managed to thin the stall down to 24 EPs and 2 powermates.A few where purchased for tests and then sold off.BGO`s went as another set of Meade RG`s where found and as i binoview that means any EP i use i need a duplicate's. :D

Giving this a thought,i might get rid of few more Ep`s over the week end.Keeping Meade Rg`s and pair of baader 35 eudias + 2 powermates.

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Stu

Stu

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It seems to me that the chaps with big dobs only need a few longer focal length eyepieces, say 21, 13 and 8mm ethos plus perhaps a Powermate. When I use my 16" (unfortunately quite rarely) I find the 21mm stays in the focused alot of the time so I get this completely.

Those of us burdened by the affliction of refractor addiction seem to need far more, particularly if you have scopes with varying focal lengths. Packing them in at the shorter focal lengths allows better tuning of the mag to the seeing conditions.

I've moved away from discrete eyepieces at this end and now have a couple of nice zooms, Leica and Swarovski. When used with a good Barlow this gives me the ranges I need.

Shane's formula seems uncomfortably accurate, although in another thread we seem to be settling on the number of eyepieces = 2 x the number of scopes you have :)

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niallk

niallk

Posted
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It seems to me that the chaps with big dobs only need a few longer focal length eyepieces, say 21, 13 and 8mm ethos plus perhaps a Powermate.

When I bought my 15", David Kriege from Obsession kindly sent me a letter, and suggested the following EP advice:

Best 3 EP set for the 15" f/4.5:

26mm Nagler, 13mm Ethos, 6mm Ethos

Best 4 EP set: as above, adding the 21mm Ethos [ :) Estwing! ]

Other than that, he recommended an O-III and Interstellarum.

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Paul73

Paul73

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So does wider FOV = Smaller number of eyepieces?

Could be something to do with getting the max usefull magnification whilst framing an object(s)? With the really wide eyepieces, the framing issue reduces as with 100°, you can get pretty much anything in field.

Or, is the limiting factor one of finance. ie. 3 Ethos = Small Car. 6 Ethos = almost certain divorce and bankruptcy?

Paul

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bomberbaz

bomberbaz

Posted
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Re: binoviewers, I am looking into this and it could see me making do with 3 EP's, scarey though that sounds to all you compulsive eyepiece purchasers  :grin: (did I just discover a new disorder = CEP) it might be something I go for. No firm decision made here yet as it would be rather expensive.  :cool:

Steve

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Stu

Stu

Posted
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I find it is not so much the difference in focal length, but more the differences in focal ratio of the scopes that drives the number of EPs up, because you need more to arrive at the required range of exit pupils on all scopes

Of course that's a factor too Michael, maximum/practical high mag in each scope depends on exit pupil but best useable high mag under the prevailing conditions is more focal length related I find.

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Highburymark

Highburymark

Posted
Posted

as my daughters would say, I'm well jell - although thankfully it's in my youngest's genes though - only 18 but seeing PIL tomorrow and Happy Mondays next month!

Should have warned you earlier Shane, you never quite recover after seeing PIL - it marks you for life. Hope your daughter survived the experience.

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Charic

Charic

Posted
Posted

So what is the perfect number for a single scope?? I say 7. What do you think?

What are your thoughts?

Paul

......has to be 6.......or could it be 1?

Having some fun playing with numbers,  the first perfect number is actually a 6,  28 being the next! A six perfectly matches my telescopes focal ratio, providing a power of 200x from my 200mm apertured telescope ( matching the Skyliners design capability ) therefore my perfect solution could be for  one eyepiece,  one telescope,  one power,  but  not desirable, as the scope is also very capable using much lower powers, so I need at least one more eyepiece, providing  two eyepieces to choose from, one high powered and one low powered, but what about the huge gap in-between? So to get the best from this scope, I need more eyepieces, and with 17 to choose from at present, just to best frame  my target, who's counting? in fact there are more!

Fortunately for me, I can afford so many eyepieces, considering their budget prices, and really do enjoy swapping them out during my sessions, all hands on, manual  only observations.

Its a  great amount of money to do the same with the likes of Tele Vue premium eyepieces, but you don't need to build a set in one Month. It can and should take a while to build a decent EP collection ( and yes, those new to observing, and thinking of upgrading their Skyliner EPs,  my  ED Starguiders are very good. I have not tried anything premium yet. and possibly for good reason, the BSTs work  very well,  and probably with my eyes, I would observe the same  visual result from a premium EP?  My Plossl EPs are  just for comparison tests and one set will eventually go?  )  Search and learn to find out what's best for your requirements, to match your scope and YOUR eyes!

As always, any thread on eyepieces is always subjective, and user opinions vary so much. I believe that the more eyepieces you have, the more choices you have, whereas having only two Delos and a Panoptic ( a choice I envisage for a new scope?) will leave me with  far  fewer options!

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alan potts

alan potts

Posted
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I had 4 hours last night with a stunning sky and the Dobsonian and I counted the use of 4 eyepieces. Sadly for anyone thinking, that's not so bad is it, the cheapest one weighs in at 460 quid so not exactly an everybody option. The 31mm Nagler is a wonderful finder eyepiece in this scope, I nearly got rid of it a few months back and the Ethos range come into their own on these scopes.

Alan

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mikeDnight

mikeDnight

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Three eyepieces would be an absolute minimum for me and not ideal. It's best to have a careful selection that will allow the observer to frame the object well and enable the observer to fine tune the magnification, so as to compensate for variations in seeing conditions.

My own selection consists of

20mm Pentax XW 70° giving a true 1.9° field @ X37

10mm Pentax XW. 1°. @ X74

7mm Pentax XW 0.7°. @ X106

5mm. Pentax XW. 0.5°. @ X148

3.5mm Pentax XW. 0.3°. @ X211

2.5mm Vixen Lanthanum (45°). 0.2°. @ X296

Takahashi 1.6X Extender Q allowing magnifications using the above eyepieces of X59, X118, X169, X236, X338 and X474 respectively.

I also use a binoviewer, X2 Barlow and 16.8mm Orthoscopics, great for lunar and planetary.

Mike

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