WANTED...Premium EP

Tamtarn · #1 26-09-2006, 03:51 PM

Anyone out there in the IIS community who may have a Premium EP with good eye relief in the 14mm-17mm range and may be considering parting with it. We would be interested in purchasing such an EP secondhand.

Let us know what you have........It will be going to a good home

Thanks

Barb & David

Astroman (Andrew Wall) · #2 26-09-2006, 05:18 PM

Have you looked at the radian series of EP's from TV? They have about 20mm ER, with 60 deg FOV. Reasonably cheap too, check out bintel.

Tamtarn · #3 26-09-2006, 05:49 PM

Actually Andrew I was just browsing info on the Radians as you were writing your post, some of the reviews are very good they're one brand to keep in mind.
Thanks for your reply

Barb

ausastronomer (John Bambury) · #4 27-09-2006, 11:35 PM

Barb/David

I rate the Radians as "pretty good". They do have good eye-relief and are comfortable to use. They work very well at F5, have good light transmission and are sharp. AFOV is 60 degrees and that slightly narrower FOV is noticed when compared to 65 deg AFOV eyepieces and wider, but it's still pretty good. Radians also give a warmish (slightly yellow) colour tone to my eye, which I don't really like for lunar planetary observation, but others do. This won't be an issue for DSO observation.

If you are interested, Kendrick in Canada have a great sale on at the moment which sees the TV Radians going for $Can 191 which you would land here for about $250 brand new. This is a great deal.

http://www.kendrickastro.com/astro/spl_epsale.html

That all having been said, it's not as good an eyepiece as the 14mm Denkmeier IMO, but a pretty good alternative. It all comes down to how good you want to go and how much money you can afford to spend. The 17mm T4 Nagler is also a way better eyepiece, but also a lot more money.

CS-John B

Tamtarn · #5 28-09-2006, 08:47 PM

Thanks guys we have decided a Nagler 17mm T4 will suit our purpose. If one is not available secondhand we will eventually have to order one

Starkler (Geoff) · #6 28-09-2006, 09:12 PM

There was a recent thread on cloudynights discussing the 17mm t4 vs the 16mm t5. The t5 was said to be considerably sharper at the expense of tight eye relief. Worth checking out.

janoskiss (Steve H) · #7 28-09-2006, 11:03 PM

16mm T5 being the shortest FL in a scaled series is going to be risky without trying first to see if you like it.

astropolak (Joe) · #8 29-09-2006, 07:24 AM

Hi there
I own 17mm t4 and find it very good indeed.
Word of warning here - it is a very heavy 2" eyepiece and if your collection of eyepieces are mostly 1 1/4 you will have a balancing problem not to mention the need to use 2 - 1 1/4 reducer. The eyepiece has field lens (the one on the bottom of the T4 facing the telescope) so close to the edge of the 2" skirt I am always afraid I will damage it. As a result I find myself using the eyepiece less. I think the eyepiece is too heavy, too easily damaged and too expensive.

Joe

wavelandscott (Scott) · #9 29-09-2006, 08:51 AM

Quote:

Originally Posted by Starkler

There was a recent thread on cloudynights discussing the 17mm t4 vs the 16mm t5. The t5 was said to be considerably sharper at the expense of tight eye relief. Worth checking out.

I can agree with the sharpness and relatively tight eye relief...I own a 16 T5...it is "sharp" but the eye relief is a bit short for some...I don't mind the short eye relief but I do notice it...

I have not compared it to a 17 T4...

Tamtarn · #10 29-09-2006, 09:15 AM

Hi Joe

Good to hear you find the 17mm T4 good.

I've noticed the bottom lense is close to the eyepiece skirt.

If you add a 2" filter ( with glass removed ) onto the threaded base of the eyepiece this will give you an extra 5mm from the EP lense to the base for added protection.

BTW if your not happy with doing this, and you're not using the EP very much you could always sell it to me

David

ausastronomer (John Bambury) · #11 29-09-2006, 10:56 AM

David,

FWIW the 17mm Nagler T4 is phsically about the same size as your 27mm TV Panoptic. It is heavier, but shouldn't cause a balance issue with your 12" dob. I have used it in my 10"/F5 (non standard altitude bearings) and it doesn't have any balance problems.

It was actually Joe's 17mm NT4 I had in my scope.

That's a good idea with the 2" filter ring at the base also, but you will need to unscrew it to use a 2" filter.

CS-John B

mickoking · #12 29-09-2006, 12:54 PM

I have an old style 'hand grenade' 13mm Nagler and it is heavier than my 27 pan, there are no balancing problems with my 300 mm gso Dob.