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TeZZa
20-05-2006, 07:07 PM
Whats the difference between the 2" and 1.25" eyepieces (and don't say .75"!)?

astrogeek
20-05-2006, 07:15 PM
.75"........well you asked for it :)

Seriously though that is about the only difference as far as I know. There is no difference to the amount of light making it to your eye (as I thought there would be) or anything else. The larger FOV (Field of View) Ep's tend to be 2" because they need the larger body to accommodate the lenses used in their design. Someone please correct me if any of this is wrong :)

Leon

vespine
20-05-2006, 08:51 PM
they say a picture is worth a thousand words:
http://www.iceinspace.com.au/forum/attachment.php?attachmentid=12626&stc=1&d=1148122255

astrogeek
21-05-2006, 09:22 AM
If only it were worth a thousand posts then your post count would have just shot up :)

matt
21-05-2006, 09:28 AM
You could have used a 1.25" ep with a larger eye lens.

That's a little deceptive.

A vixen LVW or Pentax XW would offer a fairer comparison.

vespine
21-05-2006, 01:35 PM
Send me one and it will be my pleasure ;) :lol:

That's all I have to work with, so you mean that the LVW and XW have a significantly bigger eye lense? Now you got ME interested, can someone post a big pic of one of those next to a plossl??

matt
21-05-2006, 01:52 PM
Significantly. They are wide angle EPs

davidpretorius
21-05-2006, 02:09 PM
starting out, stick to 1.25", everyone sells them, prices are competitive, more to choose from.

Houghy has gone 2" for most I think, but he knows what he likes. They also tend to be very expensive!!!

I would say that going 2" is at that stage when you are looking to spend many $100 on a single eyepiece after looking thru 100's before hand.

mickoking
21-05-2006, 02:16 PM
I use mainly 1.25" with a few 2" e/p's. For short focal lengths there is really no advantage to 2" barrels. 2" eyepieces are usually long focal length (low magnification) and wide angle.

I hope that helps :)

janoskiss
21-05-2006, 11:29 PM
Someone has to stick up for them poor defenceless 1.25s.
So here's another picture.
Top row, all 2": 27mm Pano, 30mm Superview, 17mm T4
Bottom row, all 1.25": 26mm Meade 5000 PL, 13mm Stratus, 10mm XW

The real diff is that the true FOV of a 1.25" vs 2" is limited by barrel size to approx 1600 vs 2000 degrees divided by the focal length of the scope in mm. e.g. 10" Dob with FL = 1250mm: Max possible true FOV of 1.25" EP is 1600/1250 = 1.3 degrees, of 2" is 2000/1250 = 1.6 degrees.

TeZZa
23-05-2006, 11:57 AM
Thanks for all the advice and pics, very interesting for a complete novice like me. Its a shame you can't rent them like DVDs, or try before you buy! :D

TeZZa

JohnG
23-05-2006, 12:08 PM
TeZZa

Your in Sydney, there are a few Astro Clubs there, go to a meeting and ask them to let you look through various eyepieces, I am sure they will be more than happy. Best way for a beginner to learn, they will also no doubt, have a number of different telescopes as well.

Cheers

JohnG

xstream
23-05-2006, 03:31 PM
TeZZa, Why don't you go along to Kulnura (http://www.iceinspace.com.au/forum/showthread.php?t=10081)this weekend. The guys there will make you feel more than welcome and I'm sure they'll let you try out a few eyepieces.

ving
23-05-2006, 03:38 PM
sure they would! friendly bunch :)