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Sensible EP upgrades from Standard Skywatchers?


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I totally agree with Paulo. I do not use a Barlow for observing planets. I have the 9mm TMB you refer to as well as the 6mm for that purpose and they are very good . They would both work well with you scope. I too have experimented with cheap Barlows and never kept any of then very long. I eventually bought a Celestron Ultima 2X after getting lots of advise on here. It is truly excellent. I bought from USA at the time and saved nearly £30 compared to UK price. They can be snapped up for £50-60 second hand, although patience got the better of me so the USA option.

Edited by Damo636
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If you would like to replace both SW eyepieces, you could do that with only one eyepiece - a 20mm. wide angle (66-70deg) if you already had a x2 barlow included in the telescop set. It will has bigger TFOV then your Sky watcher 25mm (I mean you will observe greater sky area) while at the same time you will have greater magnification with it. Finally barlowed this eyepiece you have a 10 mm one, with more eyerelief and FOV than the Sky watcher 10mm one. Be careful about the design of this new wide eyepiece it should be erfle or other without built in barlow because otherwise you may degrade the image while use it as a 10mm.

TFOV= Eyepiece FOV / Magnification

P.S. Sorry for my English if there are any mistakes

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A 24mm wide angle eyepiece (say with a 68 degree field of view) shows as much sky as a 32mm plossl does, but at a higher magnification which helps darken the background sky and make deep sky objects just a little easier to spot.

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I think, yes. It looks exactly like GSO and TS wide angle eyepieces (maybe the same chinesе manufacturer), multi coated and I think it worth the price and in slow telescopes (>7f-8f) there will not be noticeable difference even at the edge of field.

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I think, yes. It looks exactly like GSO and TS wide angle eyepieces (maybe the same chinesе manufacturer), multi coated and I think it worth the price and in slow telescopes (>7f-8f) there will not be noticeable difference even at the edge of field.

It mentions in the description they are identical to the Williams Swan WA, which are quite a bit more expensive!

I feel my wallet lightening a little more in the near future!:(

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Many thanks, think its the route ill be heading down for eye pieces with such a variety of combinations to give me different options it seems very good value for money.

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A 24mm wide angle eyepiece (say with a 68 degree field of view) shows as much sky as a 32mm plossl does, but at a higher magnification which helps darken the background sky and make deep sky objects just a little easier to spot.

Wow it is probably just me, but I cannot get my head around that at all. Would you mind explaining that for me? I am guessing that is why you pay more for a greater field of view?

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Wow it is probably just me, but I cannot get my head around that at all. Would you mind explaining that for me? I am guessing that is why you pay more for a greater field of view?

The way it works is best demonstrated using an example.

A 32mm plossl has a 50 degree apparent field of view (AFoV). When used in a scope with a focal length of 1000mm it gives a magnification of 31.25x and shows 1.6 degrees of sky (the true field of view or TFoV).

With a 24mm Hyperion (for example) which has a 68 degree AFoV, in the same scope you get 41.67x magnification and it shows 1.63 degrees true field of view.

What you will pay for is for the wider field of view to show crisply defined stars right across, even with a fast scope (eg: F/5).

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Thanks for the clarity comrade!

Is there perchance a beginners guide to the makes of eyepieces? A televue one at all? I have read all the choosing and deciding guides already.

It's such a changable world I don't think a comprehensive guide would remain current for very long and different people like different eyepieces for different reasons so there are no definative answers I'm afraid :(

If you read the eyepiece choice threads on here (and there are more of those than scope choice ones I reckon !) you will see certain brands / models being repeatedly recommended in the various price niches / usage categories.

I find the the reviews section here and on the Cloudynights reviews site very useful as well as posting specific questions here.

Here is a link to the Cloudynights review site:

Telescope Reviews | Cloudy Nights

Edited by John
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I've read on here that the EP's are actually re-branded Meade 4000 series...

I've got both GSO Revelation & Meade 4000 plossls. Although similar they do have differences such as the GSOs having a retaining groove.

Both are good :(

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Woops, luckily I have got a decent bonus at work (no I'm not a banker and it's nowhere near a million or two!:)), just ordered a couple of EP's!

Went for a TMB Planetary 6mm, 150x in my scope, so should be quite usable, and a 20mm Adler WA (recommended on here) with a 70mm apparent FOV, which should give me some nice views!

I'm keeping the original "kit" ep's, the 25mm isn't bad and the 10mm was giving ok views last night too. If I sell the scope then I it would be good to included the EP's and sell it as a complete OTA.

These are absolutely my last purchases for a while.....apart from those motor drives, and maybe a polar alignment scope. What's that? A new finder scope? No, don't need all that at all!!!! Just need a clear sky!:(

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I also never use a barlow when observing planets. I'm more then happy with the view a 8-9mm EP gives me.

I went for the 6mm! Hope I wasn't being too optimistic regarding the performance of my scope!

It gives 150x, quite high, but well within the theoretical max of the scope, and I've read that refractors can be pushed a bit more too.

Will soon find out!:(

Sorted the mount by the way, you were right last week, it's quite easy. First outing made a big mistake and set the latitude 10degrees too low. last night it was crudely aligned but I could track with just RA! :)

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Interesting, maybe it's like some camera lenses, they're essentially the same optical arrangement encased in slightly different bodies?

The plossl optical layout will be the same (4 lenses in 2 groups of 2). It's the quality / accuracy of machining, light scatter control, glass type and coatings that vary, and can make a lot of difference to the performance - it's what sets a good plossl apart from an ordinary one.

The lower cost wide angles tend to be based on a 5 lens erfle design.

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The plossl optical layout will be the same (4 lenses in 2 groups of 2). It's the quality / accuracy of machining, light scatter control, glass type and coatings that vary, and can make a lot of difference to the performance - it's what sets a good plossl apart from an ordinary one.

The lower cost wide angles tend to be based on a 5 lens erfle design.

Gone for the lower cost WA option! Decided I can't go far wrong with the Adler 20mm WA. Claimed to be the same EP as the Williams Swan WA but half the price. At the end of the day it's a couple of pints and a curry!:(

Think it is the 5 lens design, but 70 degree apparent FOV isn't too bad! Has to be better than the kit EP's.

I need to stop buying! Luckily I'm still on a budget, so EP's over £40 are not on the cards:)

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Gone for the lower cost WA option! Decided I can't go far wrong with the Adler 20mm WA. Claimed to be the same EP as the Williams Swan WA but half the price. At the end of the day it's a couple of pints and a curry!:(

Think it is the 5 lens design, but 70 degree apparent FOV isn't too bad! Has to be better than the kit EP's.

I need to stop buying! Luckily I'm still on a budget, so EP's over £40 are not on the cards:)

With your scope it should work just fine :)

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With your scope it should work just fine :(

Yeah, I'm not after perfection, just good value and something that will be better than the supplied EP's and a little future proof. I'm quite likely to go down the route of a bigger Newt at some stage.

If the 20mm is the same as the Williams SWAN then it should be ok, based on the SWAN reviews!:) The TMB gets good reviews all the time, so I think it's a safe bet.

I think my scope won't be too fussy anyway, F10 and only 90mm, it's not really going to highlight too many deficiencies!

However, when I get a 250mm F/5 things might change, but hopefully I'll have some reasonable EP's that won't actually be too bad! <need a fingers crossed Emoticon:)>

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If the 20mm is the same as the Williams SWAN then it should be ok, based on the SWAN reviews!:( The TMB gets good reviews all the time, so I think it's a safe bet.

I think my scope won't be too fussy anyway, F10 and only 90mm, it's not really going to highlight too many deficiencies!...

You work things out the same way I do - do loads of reading, take the balance of opinions and make a reasoned decision based on the balance of evidence :)

Yep, F/10's are not too fussy on EP's. F/5's are a different matter entirely though :)

Hope you enjoy the views :D

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You work things out the same way I do - do loads of reading, take the balance of opinions and make a reasoned decision based on the balance of evidence :(

Yep, F/10's are not too fussy on EP's. F/5's are a different matter entirely though :p

Hope you enjoy the views :)

Thanks John, I fully intend to. :D

I agree about the working out too. Sometimes it gives me a headache though!:)

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