ep's selection recommendations ?

[vindictive666]

morning all

i am very close to ordering my new 12 incher :) (yay)

i and i am being offered 4 ep's 2 of which i can chose of his listing.

anyhoo what i was wondering which 2 would be a good choice ?

Comments invited :)

also does anyone know if the primary has been spotted or is that something ive got to do later ? ( 12 incher from lee)

:cool: :astron: :confused:

[MintSauce]

I take it your buying a GSO dob from lee andrews? in which case there are loads of threads about which eye pieces to get - for instance me & frostie discussing the very same issue before ordering our 8" ers. do a quick search and narrow the choice a bit.

[janoskiss]

The 9mm and the 25mm GSO Ploessls come with the scope. If you're not buying extra EPs or a barlow, the 6.5mm & 15mm are probably your best choice for the other two, because that will cover a good range of magnifications, without any big gaps.

[iceman]

I don't think the mirror is centre spotted from Andrews, you'll need to do this if you want to collimate accurately.

I've got 9, 15, 25 and 32mm eyepieces, as well as a 2x barlow. I use them all in all combinations, depending on what you're looking at.

If you can afford it, get a GS SV 30mm at the same time, wonderful widefield views for open clusters and starhopping. And then you won't need or want a 32mm plossl.

[janoskiss]

ballaratdragons Ken's 12" mirror came centre spotted.

[vindictive666]

thanks for your responses people

being a total nooooooooob :)

i is not really looking forward to removing a mirror for centre spotting just yet

i have got a web page saved on how its done :)

[iceman]

ah ok, maybe it's something new that the factory do now.

That's good!

[ving]

hi vin, I got my 8" from there and it was supplied with a gso 9 and 25 mm. i got a 6.5 (good for tough double splitting and closups of planets) which has a reasonable eye relief and a 15mm which is just a good mid-power. this gives you a good range to work with.
the GS SV30mm in 2" that ice is talking about is something you should definitely consider :)

[MiG]

Supplied with GSO 9 and 25 or Andrew's series 500? I thought the included eps were Andrews 500s.
Anyway, the SV 30 mm is quite nice even though I have seagulls affecting the outer third of the image. The seagulls are alright if you view them with peripheral vision. If you want to concentrate on something at the edge of the view, move the scope.

I got the series 500 4 mm and last night I realised how to make it usable. Just pull the rubber eyecup off completely. Now it's actually quite easy to see the whole FOV without pain and wobbling (from pushing eyecup into eyesocket).

[ving]

supplied with the soft cup GSOs. got 2 500s thrown in. they arent too bad :)

[ballaratdragons]

Hi Vindict,

I got the Andrews 12" and it is centre spotted (with the laser hole in the middle). But mine is the Deluxe, better check with him.

If you don't have to take the 6.5mm EP don't get it. It is just too much for a 12" f5.

The 9mm, 15mm and 25mm Plossls are a treat. I would love to swap my 6.5mm for a 20mm.

The EP's that come with the scope from Andrews are GS, not Andrews brand.

Definitely get a GS 30mm SuperView 2" EP. You won't regret it. It is a real Galaxy magnet!

Are you ordering the standard 12" or the Deluxe with the Crayford Focuser, Black tube inner, cooling fan and BK7 optical glass mirror?

[MiG]

Hmm, I'm not sure about that. I've been using the 4 mm Andrews EP (313x magnification) on planets and since pulling the eyecup off it's quite nice to use.
Seeing wasn't good last night so I'm not sure about the optical quality of the EP.
The rule of thumb for diffraction limited max magnification is 2 x aperture in mm, so for my scope it's 500x and for your scope 600x.
The 6.5 mm on the 12" only gives 231x.

[ballaratdragons]

Thanks MiG, I'll try mine without the eye cup. Then I'll comment on the quality. (could be just a dud EP).

Please ignore my previous statement Vindictive, I need to check my EP.

[RAJAH235]

Vin, see my post in Beginners/Equip Opinion/Hello by Thiink re; An easy way to centre spot. HTH. :thumbsup: L.
ps. If anyone can tell me how to attach a quote, please do so.

[iceman]

[ quote]blahblah[ /quote]

comes out as



Remove the spaces.

[ving]

I removed the eyecup from my 6.5mm and ran my eyeball straight into the lens :(
think i'll keep the eyecup on.

[MintSauce]

hoho.

so we've came to the same conclusion as the last few threads, a 6.5, 9, 15 and 25 mm :D - I went this way, I think frostie wanted a 30mm or something (but I got the Andrews 80degree 30mm)

you should work out all the magnifications of those and maybe get a barlow.

G.

[vindictive666]

to answer ballaratdragons question as to what ive ordered is the 12 inch deluxe version 1149 plus 150 for delivery and insurance
all i know is that is comes with the crayford and is centre spotted (wheww :) )
i get the standard 9 & 25 mm eps plus i can chose an other 2 from his list of the 500 series i chose the 15 and 25 the 30mm gs sv will have to wait untill next time :)
same for an barlow .
plus i got an cheshire collimator as well for 49 dollars apparently it is an aluminium one i think he said (shocking memory :) )


as iam writing this the sky gods are doing their usual thing

clouds thunder ect ect but no rain

now its just a matter for me waiting for it to arrive :0

[janoskiss]

Sure you want two 25mm EPs? The GSO 25mm EP that comes standard with the scope is better quality than the "bonus" EPs.

[ballaratdragons]

I have learnt another lesson (you learn something new everyday, they say)

I have just gone to remove the eye cup from my 6.5mm EP and I have now learnt to check things first . . . .

my 6.5, 9, 15 & 25 are all 500 series! I took it for granted that they were marked 'GSO'. I had never read them properly. <i><b>Shame on me.</b></i> I can't blame bad eyes on that one, just stupidity!! :ashamed:

My GS SuperView is 'GS' coz it says so!

Sorry if I have mislead anyone in hope of getting GSO EP's with their scope.

Quick, kick me!!!

[janoskiss]

That's no good Ken. The two GS Ploessls are supposed to come standard with the scope. It must be just you, because you got the initial $999 super deal for the deluxe scope with the buttery focuser, before Lee realised that he's running a business & not a charity.

[iceman]

The bintel scopes are supplied with GS plossls.. I know this because mine are GS plossls. I got the 4 of mine with the scope.

[ballaratdragons]

That'll teach me!

Gonna have to get me some good GS ones now. Could be half the problem with trying to get perfect focus.

Thought something was a bit odd when my old melted Huygenians gave better views in my 4.25" reflector, but surely the Series 500 can't be that bad.

[janoskiss]

Ken, You're joking, right?! about the Huygensians giving better views! The 500's are not bad at all; very similar to the GS ploessls. Perhaps not quite as sharp near the edges, but I have little to compare: 9 & 25mm GS vs 4 & 20mm Ser-500. Then I also have the Dick Smith Ploessls at 6,10 & 30mm. The 6 & 10 are pretty horrible; lots of internal reflections and glare.

If you have focus problems, your EPs are definitely not the cause.

[Striker]

Time for a new scope KEN...can I suggest LX200.....

[ballaratdragons]

<b>O.K. Are you all ready for a shock!!!</b>


Today I made an adapter to take my 20 year old melted and distorted 1" Huygenian EP's. (adapter made from an 'Oates' paint roller extension handle attachment).

The clouds have just parted for about 10 mins so I raced out with the scope.

No time to wait for cool-down time, stuck in the H=20.

BLOOMING HECK!! It is crisp, clear and focuses.

Clouds coming back, stuck in the H=12.5. Same result.
Quick star test - passed with flying colours!!!!!!
Saturn and Jupiter as clear as photos, beautiful coloured bands.

Quick, try the H=6. No good, too melted.

Back to the H=12.5 tried Orion Neb. Beautiful!!!

Split Alpha Cent - easy!!! even through haze.

Clouds came back, now I'm writing this in shock.

My damaged 20 year old 'K Mart' el-crappo 1" Hugenians have out-performed the Series 500 Ep's.

I am definately getting new EP's. These ones are terrible!

Steve, your 500's might be good but these aren't.

Tony, stick your LX200 (for a year or two anyway)

I thought I was doing something wrong in the collimation, but no, it's these blasted 500's.

[MiG]

LOL, isn't life amusing.

[RAJAH235]

Buy *MEADE*. :thumbsup:

[ballaratdragons]

Got to laugh though.

These Huygenians were $3.99 each at K. Mart (20 years ago, but)

[ballaratdragons]

Clouds have gone again, sky is clear, and to be fair, I have gone out to do a comparison.

The mirrors have cooled (1 hour). I placed the Series 500 15mm Plossl in the barrel. Yep, same as before! Seagulls flying everywhere, and can't get a crisp image.

Took out the 500-15mm, swapped it for the H=12.5mm (closest two for comparison). Better image. Stars are pinpoints.

Jupiter - 500-15mm, good image but Galilean moons are seagulls.
H=12.5 - Perfect image, coloured bands clear and distinct, moons crisp.

The only problem with the Huygenian is the usual Huygenian problem, crappy around the edge. But centre is amazingly perfect.

Got me buggered! :confused:

p.s. These are not the plastic crap Huygens you get these days, these ones are Steel shaft, Steel top, and plastic inner.


<i>EDIT: Something even more laughable - The fog has rolled in so I packed the scope away, brought the Huygenians in for a good look,
<b>and the lenses aren't even clean!!!</b></i> :confuse3:

[ving]

and you had how much to drink? ;)

[ballaratdragons]

I don't drink, maybe that's the problem.

I was talking to next door neighbbour today (the retired Physics and Maths Professor). This is how the conversation went.

<b>Me:</b> Tried my old Huygenians last night in the 12 incher and found they work better than my new EP's.

<b>Him:</b> Yes, that's right. (blank faced)

He said that with a look of "so, what's the problem".

The next thing I said was a big mistake if you know my neighbour (he never shuts up). I said: "Why?"

You never ask my neighbour "why?" unless you have nowhere to go for the next week.

He then went into the most complicated and mind-boggling facts and maths about radius of curvature and pi = square something and K1 to P1 to D1 and all this Algebra stuff, then the history of when he ground his own lenses with his students and effect of curvature on curvature, multiple elements. One and a half hours later my missus finally dragged me away as we were late for my youngest daughters 14th birthday tea.

I did not understand 90% of what he said (as usual) but I must admit, the bloke is bloody clever.

Apparently (short version) Huygenians prefer a Parabaloid to a spherical objective more than other types of EP's because it has a negative lens and the convex field lens also adapts itself better to the Parabaloid.

In plain lingo: the Convex Field lens is a perfect match to the length of light rays from the mirror (unfortunately only at the centre, that was their downfall).

So, after all that I am still not much wiser, just more confused, but apparently Huygenians love my size scope! but don't like small refractors.

[janoskiss]

Very interesting Ken. Thanks for keeping us informed. Might have to look into this... :confuse3:

[ballaratdragons]

Steve, come and talk to my neighbour about it. But bring a tent, you'll be stuck with him a looooooong time.

[ving]

and a sleeping bag and a flask of hot chocky....

clear as mud that was :P