2" EP for 12" Dob

frogman (Anthony Lord) · #1 07-04-2005, 12:00 PM

Just curious what EP'S you boys would buy if you owned my 12"dob and wore glasses ? ? ? ?

Im getting a 1RPD soon ummm 2" 30mm

Or even a few (no more than 2) 1.25's that have good eye relief and would compliment my dob.?

It will be one of the things i want to talk to the guys that are coming up on sat. about.....

No more than ......$150 $170 mark.

Antony

ving (David) · #2 07-04-2005, 12:09 PM

the GSO SV 2" 30mm is really good for its price. there are a few owners here.

bout $80 i think

ausastronomer (John Bambury) · #3 07-04-2005, 01:54 PM

Anthony,

I have a 2" 30mm GSO Superview which I will bring on Saturday for you to try. The 30mm is ideal for your 12"/F5 as it creates a 6mm exit pupil which is about as large as I care to go. Younger people may get away with a 7mm exit pupil under dark skies but I prefer the darker sky background and contrastier views provided with smaller exit pupils.

In the price range your looking at you won't find a better performer in an F5 scope. Some may like the cheap widefields (80 deg) but to my mind they perform fairly porrly in an F5 scope.

Try it and see if you like it, for $79 they are hard to beat.

CS- John B

iceman (Mike) · #4 07-04-2005, 02:11 PM

I can concur about the 80deg widefields.. I have used the Andrews UW80 30mm in my F/5 10", and only 2/3rd of the field was sharp.

The SV30mm is definitely the pick for the price.

ballaratdragons (Ken) · #5 07-04-2005, 02:14 PM

Yes Anthony, I would recommend the GS 2" SuperView 30mm. I wear glasses when viewing and find it has good eye relief. It is a great galaxy magnet and in your dark position you will see what I mean!

I am soon to buy a 2" 2x Barlow for it which will then give me an excellent 2" 15mm EP with good eye relief! The 2" Super View is very cheap but the quality is amazing.

A 20mm 1.25" Plossl is comfortable on the eye with glasses but when I get down to 15mm I have trouble. The 9mm is very hard and the 6.5mm drives me crazy so I often take my glasses off to use it. (not a perfect view but a view nonetheless)

If I could get a 2" 9mm and 6.5mm at reasonable prices I would get them so I can see what I'm looking at.

iceman (Mike) · #6 07-04-2005, 02:18 PM

Anthony you'll get the chance to look through a variety of eyepieces this weekend in F/5 scopes like mine and John B's, and John has a great selection of EP's but there wouldn't be too many under $150.

Rod has the GS 15, 20 (1.25") and 30mm (2") so i'm sure you'll get the chance to try them out in your dob this weekend.

If you really need eyerelief you might have to spend a bit more and get a radian (good quality), but it would break your $150 budget for sure.

What focal length are you after? Something for planets, something for DSO's, or something for widefield clusters and starfields?

Striker (Tony) · #7 07-04-2005, 02:54 PM

Yes the GS 30mm is good value for money but me personaly hated the eye relief...unless you had your eye perfectly positioned and central over the eyepiece you loose FOV....sorry but I just dont like them.

If I was spending $100-150...I would buy a Meade series 5000 plossl which comes with the adjustable eyeguard.

20mm is $145 but this a 1.25 eyepiece

ballaratdragons (Ken) · #8 07-04-2005, 03:17 PM

Quote:

Originally posted by Striker
Yes the GS 30mm is good value for money but me personaly hated the eye relief...unless you had your eye perfectly positioned and central over the eyepiece you loose FOV....sorry but I just dont like them.

How else are you supposed to look into an EP? Sideways?

frogman (Anthony Lord) · #9 07-04-2005, 04:25 PM

What should i be paying for a 1RPD 30mm ??????
Second hand in good nick...

atalas · #10 07-04-2005, 05:03 PM

Anthony I have one of those cheap 2" 32mm thingy's from Andrews !
you can check it out on Saturday night plus other stuff !

Louie

ausastronomer (John Bambury) · #11 07-04-2005, 05:54 PM

Quote:

Originally posted by frogman
What should i be paying for a 1RPD 30mm ??????
Second hand in good nick...

$Nil on the basis you own an F5 scope.

These eyepieces do a reasonable job in F8 and slower scopes like SCT or MCT, they would also work well in something like the old long focus achro refractors but not recommended in an F5 scope for mine.

Clear Skies
John B

stringscope (Ian) · #12 08-04-2005, 07:34 PM

Anthony,

You have not specified what you are intending to observe with this eyepiece that you cannot already observe with your existing eyepieces.

Is your dob F5?? You will find the F5 light cone makes life more difficult for eyepieces and if you are after "sharp to the edge" performance combined with >60 degree AFoV, then you are probably limited to Televue Pentax amd some Meade products.

Reasonable quality Plossls are pretty good performers @ F5. I note you have a 30mm Plossl. This eyepiece should give you a 6mm exit pupil/1 degree field of view/50X magnification. I have a 30mm GSO SV eyepiece. This is probably the lowest priced 2" unit that is readilly available in Aus at present. By the way the actual FL of my unit is 32mm, not 30mm as advertised. At F6 this eyepeice is not particulary sharp compared to a quality Plossl of the same FL, but it is OK. The 65 degree AFoV should give you 1.3 degree FoV in your telescope. Hoverever, due to astigmatism generated by the eyepeice, I find only the inner 50 degrees are sharp.........same as your 1.25" Plossl. Icemans comments about the Andrews 30mm/80 degree UWA (similar, if not identical to the BW Optik) would indicate it has similar performance. I quite like having the wider FoV and I accept the astigmatism as trade off for the lower $.

If you are after a "finder" eyepiece then edge performance might not be as important to you. If you really want "sharp to edge" combined with wide fields...........mmmmmmm

Eyepieces are a very personal thing, if at all possible.........try before you buy.

Cheers,