Ap Fever question: 14.5" to 18"?

Hi Folks, it's been a while
(excuses:
1. out of country - sheesh, highlander prominars down under in e. africa, AMAZING!!
2. transition to another obsession - rc gliders, but now I go out into woods/mountains to throw planes off cliffs and camp out so I drag my 14.5" out with me!)

question: is it worth transitioning??...
14.5" f4.5 zambuto with mirror and cooldown fans
TO
18" f4.5 galaxy with no fans

for purely visual experience ONLY
stats say i go up 0.5mag
QUALITATIVELY is it worth it?

Sanders--
I would say only if galaxies are your primary observing interest, and even then I would hesitate. There is something, well, perfect about the 14.5 zambuto (is it in a starmaster?)--a convenient size for portability and flat-footed observing, big enough to get significant galactic details, but also a killer planetary instrument--I'm always awed looking through them. How long have you owned yours? Maybe you should spend some more time with it under a dark sky! (my $.02)
---George

I agree with George. I own a 15" Obsession and was contemplating the same thing when it was time to purchase it. Only a small jump in magnitude isn't worth the ease of portability. Jumping to an 18" will increase the size and weight of the scope. You will most likely have to purchase a small step ladder which will ad another piece to the equipment you'll have to carry. If I was to go larger then a 15" it would be in a fixed location and it would be a HUGE jump in mirror size.

No! You need the fans even more with a 18".

Some thoughts - I'd first consider upgrading to a really nice secondary (say, a 1/30th fused quartz from Antares, to pick up some additional contrast. Then I'd baffle the back of mirror box, the UTA, and make sure I have a shroud that blocks light really well (some don't, but my replacement AstroSystems shroud does). Then I'd see if the 14.5" didn't show some additional performance - mine did. (But, at a truly super-dark sky site, the baffling/shroud stuff might not make a difference.)

If that wasn't enough, my first jump-up point from 14.5" would be 20", with 24" being a more desirable size. I wouldn't bother with moving from 14.5" to 18". There is a pretty good improvement from 14.5" to 20" though.

Good luck!
Doug

Hi Sanders,
I would like to add to the thread.
I too own a Starmaster 14.5" f/4.3 with a 1/30 wave Antares secondary, ServoCat and Argo Navis, mirror box lower baffle, UTA upper baffle, UTA flocking, enhanced light shroud (thicker more opaque fabric than the stock one) upper and lower cooling fans and completely aligned optical system.
Most of the add ons were of my own design from my company, Blue Sky Accessories. But, if you make your own that is just as good.
By adding these items and maximizing the performance of the 14.5" Starmaster, it is on par with even an 18" scope. It does not quite have the brightness (slightly less) of image, but otherwise it is comparable. Even when I look through much bigger scopes, 20-24" the differences are less than one would expect.
Plus, I get to sit in my chair to view, even at zenith or stand flat footed all night with no steps what so ever. This to me is such an advantage over the evening, that I feel the loss of aperture is worth it.
I have owned scopes where I used a short ladder and have viewed with scopes that needed tall ladders to short ones. Even the ones that needed a short step ladder got to me over a nights use. The constant moving it out of the way and placing it for the individual using it, just got to be a hassle to me. Now I have a 6" plastic platform about 12" x 30" for my wife to use that is light and will not tip or move. It is not bad and it is only used when a person under 5'4" is at the EP and then only when the scope is aimed high.
I believe that you can optimize a scope and gain a bit of performance. I also believe that aperture rules generally, but for me too much is too heavy and difficult to set up as well as use for 8 hours.

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Thanks Guys for responses.
Sheesh, you're suppose to help me JUSTIFY this possible purchase! appears overwhelming counsel is DONT!

the 14.5" is a teleport. What i have come to really appreciate (besides the zambuto) are ergonomics and accessories incl 2ndary heater, integreated counterbalance and tools for collimation and the fans. I hvae used fans both on and off and it is really amazing, a fuddydud like me can see the difference. the only gripe i have is that the feathertouch doesnt have enough travel for some eps.

the 18" would be the new obsession 18 UC as reviewed on cloudynights just recently. i think it comes wth either OMI or galaxy.

i am 5'3" and dont use a block or ladder with the 14.5" (i hate tracking at zenith to begin with)

Yup Floyd, out focus and that is just what i do, shim out. it sometimes bottoms out (in?) too, esp with a big barlow in place and 31nagler (i think), at that point fortunately it does snap right into focus (i thnk?)

George, that is a great quote, and i totallyagree.
you know the only time ive been able to pickout the N.Am neb was with my zeiss 20x60s binos and trust me, ive tried! with TMB, prominars, tleport - no go!

This telescope will be for darkskies only. in town or anywhere near, i pull out the prominars

and no, i will keep BOTH toys if i do commit to the 18". you'll be prying the zambuto out of my cold dead hands!

Hi Sanders,

Keep the 14.5" and buy a Mallincam integrating video camera. Seriously. It will blow away any view of a faint fuzzy you could hope to achieve in an 18". And you will save money too.

John