time line for ep's [Archive]

davidpretorius

14-07-2005, 02:27 PM

for a 10" or 12" dob, is this the best order for working thru buying your ep's:

9mm,15mm,20mm,25mm GSO's & cheshire for collimating bought when you buy your scope
barlows & wideviews.
can you see thru a cheshire, or is it simply a collimation tool?

I spose i was wondering what next to budget for in a specialised eyepiece ie barlow 1" or 2" and extra wides etc

elusiver

14-07-2005, 02:40 PM

u can't observe through a cheshire.. u can see through it.. but just for when u'r collimating.

i've only just got my dob and am pretty much following that order.... got the 9, 25 and cheshire when i got the scope.. then bought the 15 and barlow. Now i'm looking at the 20mm superview :)

el :)

davidpretorius

14-07-2005, 02:58 PM

thanks,

which barlow? and what is the main reason for barlow's and superviews

elusiver

14-07-2005, 03:13 PM

barlows basically double u'r ep collection. U get 2x from any eyepiece.. so the 20mm turns into a 10mm etc etc, although you do get a little loss in 'quality' when barlowing. So bascially with my 9, 15 and 25mm ep's i've got a 4.5, 7.5 and 12.5mm as well if i barlow them. I got the gso short barlow.. cause.. it's cheap.. and.. it's cheap. As a n00b spending big bucks on ep's at at the mo not really on the agenda. But if u did want to spend abit more the orion shorty plus is the way to go for around $150.. then after that if u wanna spend more look at the televue powermate.. big bucks but from what i've read are freakin awesome.

superviews give u a wider apparent fov, so you it's great for open clusters etc so u can fit more in, i think.. never looked through one.. so don't know for sure.. but this is just going by what i understand. But they basically make observing heaps more pleasant.

el :)

ving

14-07-2005, 03:20 PM

superviews are gret for dob users... because we dont have tracking we have to keep nudging the scope. with a superview it takes longer for the object to go thru the increased FOV = less nudging.
I hae 2:
2" 30mm sv
1.25" 15mm sv :)

rmcpb

14-07-2005, 03:45 PM

If you are getting a barlow make sure its a good one like the Celestron Optima or the Orion Shorty Plus, they are the same barlow just different badges. Both are fully apochromatic and, as a result, will give better images through the eyepiece and will be a far reaching investment.

A couple of points about optics:
- get the best you can afford and,
- take your time as they are expensive and you need to know why you are buying the eyepiece so you get the right one.

Cheers

davidpretorius

14-07-2005, 04:05 PM

Ok thanks to all, shopping list is now:

9mm,15mm,20mm,25mm GSO's (does the 'O' stand for optics in Guan Sheng Optics????)
cheshire for collimating
Would these "Andrews 80° Ultrawide (UW) Eyepieces" suit the 10" or 12" dob? and if I have a 15mm superwide, do i really need a 15mm GSO from the set of 4 above?<TABLE class=content cellSpacing=0 cellPadding=2 border=1><TBODY><TR class=tbl_text><TD class=desc>Outstanding 2" 80 [degrees] 30mm f.l. eyepiece.</TD><TD class=price>$149.00 Each</TD></TR><TR class=tbl_text><TD class=desc>NEW 2" 80 [degrees] 15mm f.l. eyepiece, available soon</TD><TD class=price>$149.00 Each</TD></TR></TBODY></TABLE>
barlow - orion shorty plus

davidpretorius

14-07-2005, 04:05 PM

asimov

14-07-2005, 04:34 PM

Dont forget to order the cheshire with cross-hair's David. (although they probably come standard these days, not sure?) The cross hairs help centre your secondary under the focuser, instead of spending more buck's getting a sight tube.

The barlow I ended up with is the Meade series 4000 2X apochromatic telenegative amplifier. I cant compare it to anything else...but it doe's a marvellous job.

asimov

14-07-2005, 04:41 PM

And may I suggest you look at this before you order EPs...

http://www.aoe.com.au/eyepieces.html

janoskiss

14-07-2005, 05:18 PM

I disagree. I don't like that the full field is not sharp, and seagulls around the edges. I still have to nudge as much as with a plossl because the usable field of the superview is no greater than the plossl. Yes, it does give you a bit more of a floating-in-space feeling, but only pleasant when you're looking at the centre of the field of view, so the blurry seagulls near the edge are in the peripheral.

Dave, If you're going to get one, get only one, and see how you like it.

Don't be tempted by the UWs. Not recommended for fast scopes. See this review (http://www.iceinspace.com.au/index.php?id=42,134,0,0,1,0) on our very own Iceinspace.

Sirius Optics have the Shorty-Plus for $135, and Bintel dropped their price to $139 as well since I pointed it out to them. (Bintel did sell me one for $135, but they charged me $4 over the online price of the camera adapter I bought at the same time, cheeky buggers.)

elusiver

14-07-2005, 05:40 PM

also.. check out this

http://www.iceinspace.com.au/forum/showthread.php?t=2644

andrews prices have changed also.

el :)

mch62

14-07-2005, 06:13 PM

In an f5 the 30mm super view will show flared stars towards the outter 25% of the view.
This is as a result of both Newtonian mirror coma and eyepiece abberations .
As there only a 5 element there not as well corrected for a fast f5 scope.
There fine for a f10. Resonable for f7.5

I would say stick with plossels as the only alternative for sharp images right to the edge of field will cost you more than the scope for one eyepiece.

Try before you buy as you may find the Andrews 30mm 80deg ok for your tastes. every body have different expectations and you may be able to live with it.

Starkler

14-07-2005, 06:53 PM

Cheap widefield eyepieces are poor performers in fast scopes such as the GSO dob. I strongly recommend forgetting all thoughts of panoptic or nagler performance at a budget price. It just doesnt happen. What you usually get is a smallish usuable field no bigger than that of the plossl, surrounded by seaguls.

If you want to do things on a budget I would recommend the following.

Orion shorty plus
12.5mm plossl
15mm plossl
20mm plossl
and either a 30-32mm plossl or a 30mm GSO superview.

The 12.5 and 15mm plossls are good for general dso work and give you two very useful magnifications when barlowed for planetary viewing.

Plossls much shorter than the 12.5 become uncomfortable to view through due to short eye relief.

asimov

14-07-2005, 07:24 PM

My GSO 30mm SV 2" in my F/5 reflector is only just acceptable...As Geoff & a few other's have said...don't bother. Now in my F/8 refractor it doe's more than an acceptable job, due to it's longer focal length.

My best wide-view EP in 1.25" format is the celestron 24mm.

Your choice of 9mm 15mm 25mm (in 1.25" format) plus a good quality barlow is really all you need for now. Ignore everything else! LOL

davidpretorius

14-07-2005, 09:23 PM

thank a heap.

4 good plossels and a cheshire it is, a good barlow later and a partridge in a pear tree.

i can't see a cheshire on andrews website, is it listed as something else?

janoskiss

14-07-2005, 09:36 PM

Andrews has the Cheshires for $29 a pop. I know cos I just ordered one. To save further delays just include one with your order. (No I don't work for him. :) ...and iceinspace.com.au is not a subsidiary of Andrews Comm. :D)

PS. I've had my scope for 6 months and it took me that long (along with some $$ spent on the wrong things) to learn the information contained in this single thread.

ballaratdragons

14-07-2005, 10:16 PM

Everyone has differing reports on all sorts of stuff.

I have the GS 2" 30mm SuperView and after letting it cool for as long as the scope, I don't get seagulls around the edge! It is brilliant for large open star clusters and BIG nebs like Orion. The Carina section of the Milky Way looks magic through it. It is also a galaxy magnet!!

May I recommend (dollars permitting) getting a 2" Barlow. Then you can Barlow any EP, as the 2" has a 1.25" adaptor.

If dollars are short the Andrews 2" 2x Barlow is only $79. It isn't the finest peice of equipment made but mine works fine.

Andrews do have the $29 Cheshire, but they are not on his site.

asimov

15-07-2005, 01:40 AM

Why in the hell didn't I think of that! DERR! Take that on board David! About the 2" Barlow. In hind-sight, that"s what I should have done.

I never even considered 2" format when I kitted myself out. Now that I have one 2" EP human nature force's one to eventually get a 2" barlow giving you in effect 2X2" EPs! ( that's how I justify it to my wife, LOL... it's HUMAN nature, my dear!) :D

That's the best advice Iv'e heard all day Ken :thumbsup:

You might be shelling out a few more buck's for the 2" over the 1.25" David, but It'll save what I & probably other's have done.......& end up with two different size barlow's! Just my 2 cents worth (plus GST) anyway.

PS Ken....How come U dont get them seagull's!? :confuse3:

ballaratdragons

15-07-2005, 01:45 AM

John,

It's coz I let the 2" sit in the cold just like the scope does and after about 1 hour of cooling the seagulls have flown away. Maybe because it's a big mother of an EP it needs cooling just like a scope!??!

asimov

15-07-2005, 01:47 AM

COOL! I'll keep mine in the fridge then! lol

ballaratdragons

15-07-2005, 01:53 AM

Then you will really be able to 'Chill out'.

davidpretorius

15-07-2005, 08:45 AM

ok, revised list

9mm,15mm,20mm,25mm GSO's
cheshire with cross hairs for collimating
2" good quality barlow with adapter
and yes.... GS 2" 30mm SuperView when money permits.
It is great this forum, we are all learning all the time!

iceman

15-07-2005, 09:06 AM

A 2" good quality barlow will be quite expensive.. The GSO 2" barlows are quite good on their own, and at a reduced price. Dave47Tuc recently bought the next price bracket up 2" barlow, there's a thread about it in the equipment forum. Take your pick, depending on your budget.

As others have said, you may or may not be able to put up with "seagulls" at the edge of the field of view. Your best bet is to look through some other scopes before making a decision.

Starkler

15-07-2005, 01:29 PM

Considering you are getting a barlow , I would delete the 9mm and replace with a 12mm.

davidpretorius

15-07-2005, 01:59 PM

thanks all again.

GS-980 Ltd. 12" Dob. has a Crayford focuser and BK7 optical glass
are the fans worth the extra $100 on the deluxe model?

elusiver

15-07-2005, 02:23 PM

i didn't think that the straight ltd has the crayford and bk7.. but the Guan Sheng GS-980-BK7-CRF has..

i rigged up my 120mm($20) fan on my 8" in a couple of hours with my dremel.

el :)

ving

15-07-2005, 02:33 PM

oh i dont know... I quite like my 9mm, its a good EP. I am only getting rid on mine because I bought a better quality one near the size.
:poke:

asimov

16-07-2005, 03:02 PM

I'd rather have a 9mm over a 12mm....Seem's to be max. mag. for night's of 'average seeing conditions' (which is 90% of the year)..... Although having BOTH work's well too!

Starkler

16-07-2005, 04:13 PM

I suggested a 12 and 15 as the 15 barlowed gives a nice mag for nights of average seeing, and the barlowed 12 for nights of good seeing . This combo worked well for me in Melbourne conditions.

davidpretorius

16-07-2005, 04:33 PM

I like the idea changing a 9 for a 12 as i assume that barlow will turn the 12 into a 6 and the 9 into a 4.5, but from looking at andrew's comm (where i will be getting the dob from) the 9 and 25 come free with the scope and the next size up is a 15mm. From a freight point of view and logistics point of view, I reckon the 9 will do the trick.

iceman

20-07-2005, 07:35 AM

I'm pretty confident you could ask for the 2 free eyepeices to be any focal length you want - you just have to ask.

I have the 9, 15, 25 and 32 GSO plossls, and like asimov, I use the 9mm on most nights as that's all teh seeing will allow for. Really, any (well thought out) combination of 3 or more eyepieces with a barlow will give you every focal length you need, if you're talking about GSO plossls.