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More ep decisions

Started by tomhole, 12/03/2003 04:53PM
Posted 12/03/2003 04:53PM Opening Post
Well, my investigations into the 24-25mm and 9-10mm ep pairs is complete. 24 Pans and 9 Nagler type 6's. Big suprise, huh? It is weird to look in my ep case and only see 4 pairs of ep's though (still have the 32mm GTO plossls and the 12.5mm orthos).

Now I am venturing into the 11-13mm and 7mm ranges. The new Starmaster has a 1508mm focal length, so I'm a little out of kilter with my ep numbers. What once was second nature is now a mental chore. Luckily, the 24 Pan fits with any scope but it certainly took a hit with the added focal length. I'm down to 86x and .75 deg TFOV as the best I can do. The 9mm hit a semi-sweet spot (230x w/ 2" OCS and 335x with the 2x corrector). I wanted to fill in around 180x (a popular Jupiter mag) and something around 280x to split the 9mm's mags. That would give me a good range of planetary magnifications to choose from for persnickity seeing and Jupiter's challenging low contrast detail. 11mm fits both those mags with the 2 correctors I have, but there isn't a lot to choose from in that focal length.

The 7mm would be used for the 8+ seeing nights and globular clusters, so not a lot of use. It would give me 295x and 431x. The 295x is somewhat duplicative of the 11mm x2, but I want access to 431x and higher. That's why I bought the Zambuto mirror. I'm thinking I should add a pair of 7mm orthos to start off.

I am also entertaining the idea of putting 2 powermates in the ep holders to get to ludicrous power. But now I'm getting back into the whacky world of multiple amplifiers that I was trying to avoid.

So, I solicit thoughts and recommendations.

Also, I talked to Rick Singmaster at Starmaster telescopes and he recommended I definitely should not crop my truss poles. But I could get a 1 deg TFOV if I went correctorless. Russ recommended against cropping as well. But the tinkerer in me is finding it hard to resist. Sometimes I wake up with the Dremel in my hand pretending to grind things wink

Clear skies,

Tom
Posted 12/03/2003 05:12PM #1
Tom,

Couple of thoughts. 11mm T5 Naglers. I have 24mm Pans and 16mm Naglers that I am using with my 14.5" f/4.3 Starmaster with a Seibert corrector (1.35X) and the 2X corrector. I also have the 3.8X corrector, but seldom use it. Anyway, I have also been toying with the idea of ditching my narrowfield eyepieces (pairs of 12.5mm Ultimas, 9mm UO orthos, 8mm RKEs) with Naglers myself. If I do so, I am leaning toward either the 11mm or the 9mm...or both!

What the hey, you already have 24mm Pans, and 9mm Naglers, right? So, you might as well indulge. I think you would be sorry going with a narrowfield anyway, having gotten used to the Pans and Naglers. Besides, I sure would love to hear about how a pair of 11mm T5's perform in a binoviewer!

Second thought is, why don't you buy a new set of trusses and the ball connectors from Moonlight? The Starmaster uses the Moohlight ball thingies anyway, so if you made a set of shorter trusses, you could have the best of both worlds...and not kill the resale value of the Starmaster.

Doug
Midway, FL
Posted 12/06/2003 07:06AM #2
Well, fate has looked favorably upon me. A nice fellow just offered a pair of 11mm Televue plossls for sale here on Astromart at a very reasonable price. So I snagged them. What are the chances of that?

I also ordered a pair of 7mm UO orthos.

I'd like to get a pair of something in the 10mm range to get a solid mix from 10-12.5. I have the 12.5 orthos already. I'm adding the 11mm TV plossls. I have the 9mm Naglers. My goal is to have a solid set of mags from 180-230x. That is Jupiter country, my friends. Seems like overkill, but as long as I stick with the less expensive pairs, it won't kill the budget.

12.5mm ortho = 165x (241x) [with 2x corrector]
11mm plossl = 188x (274x)
10mm ??? = 207x (302x)
9mm Nagler = 230x (335x)
7mm ortho = 295x (431x)

That 10mm/200x slot is a critical one for my area and Jupiter. This also gives me a beautiful spread of mags from 165x to 431x. In my limited experience, this should keep me going for a while. I'll probably add a 13 Nagler at the top for DSO.

That's my morning rambling.

Tom