More Power, Scotty, in my 102 FL!

I just bought a used Vixen 102 FL refractor with a 920mm focal length. My first light impressions are that the optics are superb and color free on the moon and even Vega. I will mostly use the scope for backyard lunar and planetary and for public star parties. My first impressions are that this scope will support some very high mag on the moon, which is one of my interests. My shortest FL eyepiece is an excellent Tak 5mm, but I think I may want just a little more power. My problem is that I must wear my glasses and long eye relief is a necessity. I love the Tak 5, but the ER is just too short. I also have an excellent Pentax XL7, but I want more power.

My question is how to get more power--the equivalent of a 3-4mm eyepiece without sacrificing ER. A couple of short FL Radians would do the trick, but how about a PowerMate 5X with some of my longer FL TV plossels? What would the group suggest might be the best scenario, while preserving ER and not breaking the bank?

Thanks,

Gordon Gower
Tucson

Any telecentric style barlow is supposed to maintain the AFOV and ER chanracteristics of an eyepiece (e.g., TV Powermates, Siebert Telecentric Barlows, etc.). Conventional barlows alter the afov and ER charateristics to a degree.

I use barlowing extensively, Ultima 2x and Klee 2.8x. I find the Ultima narrows the afov a bit more than the Klee, but ER I have not found altered obviously - although I never paid attention either.

Also, I have yet to find any EP + barlow combination that performs worse than the equivalent FL EP without barlow. Often actually better in terms of resolution. For instance, a few evenings ago I put the Nagler 12mmT4 on the Ultima barlow for an effective 6mm view. I then compared that to my 6mm OU HD and 7mm TMB/BO Planetary on the Perseus Double Cluster. No real difference! Yes, if I really really looked and examined very hard, the Nagler under barlow was ever so slightly dimmer, but not easy to notice at all. So for practical purposes, the same...which was amazing especially compared to the UO HD with its simple optical design.

So I'd suggest you get both a 3x and 5x barlow and start using the longer FL comfortable EPs for high power work. 12mm, 9mm, and 7mm EPs combined with 3x and 5x barlows will get you a nice range of effect FLs all the way down to 1.4mm!

Hi Gordon,
If you really like the Tak Ortho's, the 2.8mm and 4mm Tak Ortho's have a built in Barlow lens. These are actually what were called the Tak Hi-Point. The Barlow lens was built in to help extend the eye relief. You might see if you can locate one and try it. If memory serves, the Tak Hi-Points have a slightly longer eye relief than the 5mm Tak Ortho but not by much.
IMHO you're probably going to be happier with a good quality Barlow that can be used with various eyepieces.
Hope you find something that works well for you.

Clear Skies, Bill

Gordon Gower said:

I just bought a used Vixen 102 FL refractor with a 920mm focal length. My first light impressions are that the optics are superb and color free on the moon and even Vega. I will mostly use the scope for backyard lunar and planetary and for public star parties. My first impressions are that this scope will support some very high mag on the moon, which is one of my interests. My shortest FL eyepiece is an excellent Tak 5mm, but I think I may want just a little more power. My problem is that I must wear my glasses and long eye relief is a necessity. I love the Tak 5, but the ER is just too short. I also have an excellent Pentax XL7, but I want more power.

My question is how to get more power--the equivalent of a 3-4mm eyepiece without sacrificing ER. A couple of short FL Radians would do the trick, but how about a PowerMate 5X with some of my longer FL TV plossels? What would the group suggest might be the best scenario, while preserving ER and not breaking the bank?

Thanks,

Gordon Gower
Tucson

Yes, these Vixen Fluorites are superb scopes by any
standard! Congrats!

I agree with both Bills. What I use most in my Vixen
is a TeleVue 3x Barlow and some 9mm to 18mm orthos
(University) or Plossls (TeleVue). If you want more
eyerelief, then maybe the TeleVue 5x PowerMate with
some longer Plossls you may already have. I had tried
the Radians, but went back to my Barlow + ortho scheme.

For best bang for the buck, I would consider the TMB/BO 2.5mm and the 4mm, the 3mm will be out soon too. These are $100 new and can be found used for less.
They are not the equal to the much higher priced EPs, but they are very close and for $100 hard to beat for the eye relief and power. Plus they have a large lens which I like.