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slippo74
24-09-2009, 11:41 PM
Tonight I've decided to give a try with a large eyepiece.
I've used a 32mm (2") and realised how beautiful is the sky watched through it and how many details I'm still able to get even with such low power. After days trying to get the most from all using 15mm, 9mm and 6mm, tonight I spent almost an hour of intense pleasure and relax for my eyes... a joy to watch the sky in such comfortable eyepiece.

I have reviewed hundreds of discussions, but it seems that people have different and personal opinions in regarding.
My achievement is to keep enjoying the comfy view but with the ability to get a bit more further if needed.
Is a Barlow a good option to combine with wide eyepiece?
Unfortunately the Barlow that I have is for 1.25", so I couldn't try on my own.

Thanks in advance.

jjjnettie
24-09-2009, 11:57 PM
A good quality 2" barlow is a good investment in my opinion.
You'll still be able to use it with your 1.25" ep's because they come with an adaptor.
And on those very rare occasions of excellent seeing, you can double barlow to really get up close and personal with the planets.

mental4astro
25-09-2009, 12:00 AM
Hi slippo74,

my first question is what telescope do you have? Its size and focal length.

Me, I don't like using barlow lenses, they put more glass between me & what I'm trying to see. Also, because I mainly use dobsonian scopes, the barlow adds weight to the top of the scope, unbalancing the set up.

Saying this, I suggest eyepieces that give the widest field of view angle. Just keep in mind that these wide angle eyepieces can show their shortcomings in quality if the scope you are using has a fast focal ratio.

slippo74
25-09-2009, 12:06 AM
Hi guys, thanks for your replies.

My telescope is a reflector 150mm/750mm (and if what I learned is correct the F ratio should be f/5).

Cris.

renormalised
25-09-2009, 12:07 AM
I think barlowing a 32mm ep is sort of defeating the purpose of such an ep', which is widefield, low power viewing. However, it can give you that extra bit of oomph by bringing things a little closer than usual.

Although, on your stock standard 6-8" newt (at f4.5-6), you're going to get X42 -X80 mag with a barlowed 32mm, which is the same as sticking a 15-16mm ep straight into the focuser. Means one less ep to buy.

slippo74
25-09-2009, 12:22 AM
Ok, I got your point... but would be correct if I say that looking through a 32mm 2" with a 2x Barlow will give to my eye a sort of "less-stress" than doing the same through a 16mm 1.25"? Mine is just a supposition considering that the top lens of the 32mm 2" appears to be bigger than the one of 16mm 1.25" or even 2".

Please, forgive me if I said something of silly, I'm trying to learn as much as I can.

renormalised
25-09-2009, 12:31 AM
Oh, it is...the exit pupil for a 32mm ep is larger than for your 15-16mm, which would put less stress on your eyes.

slippo74
25-09-2009, 12:35 AM
Thanks! That was my scope :) ... really informative.

JethroB76
25-09-2009, 10:10 PM
The exit pupil of the 32mm will change when you barlow it though