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Planetary Eyepiece for Starblast 4.5


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Hey guys, 
I live in the city and bought myself a cheap starblast 4.5 for portability and simplicity. I got myself a good 2x TeleVue barlow, and all thats missing to the puzzle now is a decent planetary eyepiece. Since I live in light pollution most of what I will look at is planets, so I'm thinking of getting either a 5mm or 6mm to use with the barlow. The starblast comes with a cheap 6mm and I feel like it would put the money I spent on a good barlow to waste. 

Here are the specs of the Starblast:
 

114mm (4.5 inch) diameter parabolic mirror

450mm focal length, f/4.0

15.5 sq. in. light grasp

226x maximum theoretical magnification (based on 2x the mirror diameter in mm)

I'm wondering if anyone could guide me as to what the best magnification would be given this setup, I was thinking 150x (6mm with barlow) would be the limit, but if I have really good optics like a TeleVue Barlow and a reasonably good eyepiece, could I push 180x with a 5mm?

I'm new to telescopes and I know that zooming in like crazy is never the best way to go about things, but I dont have enough money atm to buy multiple eye pieces, and I wanted 1 good one for actual planetary views and I would like to see Saturn and Jupiter at their best. I'm currently mostly looking at the Zhumell Z Series Planetary EP's but any other suggestions would be great (preferably below 120$)

Thanks ahead of time!

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I cannot think of anything to suggest that I could even half back up with evidence.

At f/4 the scope is fast and that is the problem area. Plossls are going to be out of the question, only the TV plossl is commented as operating at f/4 and they stop at 8mm.

The planetary eyepieces I am not sure of, I have a couple of the TMB copies but they are beaten by the Astro-Tech Paradigms on performance in an f/5 scope. I have read that the A-T's start to drop off at f/4.5 and not read of anyone trying them at f/4.

Ones that are likely to work at f/4 cost lots.

I would half suggest a barlow and an 8mm, that would give 4mm and so 114x. I will also suggest you forget 128x out of the scope. I suspect 150x will be pushing your luck and 110x more probably. The scope is fast and will show coma quite extensively.

No idea where in Canada you are, it's a big place, there are Antares W70 eyepieces at 4.3mm, 6mm and 9.6mm. I think that the 4.3mm is constructed with a built in barlow one of them may be an option, something like 100x. 100x is OK for Jupiter, really Saturn needs 120x, but Saturn is not visible at present. For some time all you have is Jupiter. Possibly think along the lines of a 6mm eyepiece and observe Jupiter at 75x. Later perhaps (when Saturn appears or finances allow) get one of the Antares 1.6x barlows and so get 120x.

OK forget that as Antares only seem to do the 1.6x barlow in 2" format. Left in as there may be alternative 1.6x barlows.

There are "flat field" eyepieces, check what Astro-Tech have but I have no idea how good/bad they are. They are apparently intended for fast scopes as they are supposed to work with the greater image curvatures that fast scope produce.

Finally there is an Astro-Tech Paradigm equivalent at 3.2mm, going to be sold under the BST brand in Canada, do not think A-T mention it. One of them might work, how well it may work is the questionable bit. It would give 140x.

Really back to the idea of a 6mm Antares or a 6mm TMB planetary and at some time a 1.6 barlow - think a 2x barlow would be too much. I know that this tops out at 120x however I cannot see you realistically getting more.

Next time round get a nice easy f/7 or f/8 scope, they are a lot easier to live with. :grin: :grin: :grin: :grin: :grin:

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Passing thought but I wonder if a zoom eyepiece may be an option, I do not have any  and never used one.

Recalled that WO do a 6mm planetary but not sure if it operates at f/4, WO used to say their SWANS effectively stopped at f/6. However that has been removed from their descriptions now.

There is however several people with the 6mm WO Planetary over here and just about eveyone rates it highly.

My concern is that all these ideas could cost you money to find out. :eek: :eek:

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Passing thought but I wonder if a zoom eyepiece may be an option, I do not have any  and never used one.

Recalled that WO do a 6mm planetary but not sure if it operates at f/4, WO used to say their SWANS effectively stopped at f/6. However that has been removed from their descriptions now.

There is however several people with the 6mm WO Planetary over here and just about eveyone rates it highly.

My concern is that all these ideas could cost you money to find out. :eek: :eek:

Thanks for all the help ronin!

I probably didnt word it well, but I actually already bought the TeleVue 2x (figured it was an investment for later, when I get myself a much bigger scope), so if my magnification limit is 120x ish, I could probably look at 7mm or 8mm eyepieces. The zoom eyepieces  do look interesting, and the WO Planetary seems to have great reviews everywhere. Do zoom eye pieces reduce quality though? Ive seen many people mention it, and they seem too good to be true. If I'm looking to buy a single eye piece to last me on this scope, coupled with a barlow, I'd assume that a 6mm-20mm EP would be perfect and cover most of the magnification I would need, but I can't help but feel like there would be a catch to it. 

Also I decided to look around and it seems people get pretty reasonable views out of 150x : 

This is a pretty tough choice :p if there was an affordable quality zoom lens out there though, that would solve all my problems. 

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