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What Eyepieces


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Hello All,

 

Its been a while since Ive been on here but Im still observing :)

 

So I have an astromaster 70az refractor with a focal length on 900mm. I do plan on upgrading to a skywatcher 150pl in the near future. 

My main love is for the planets and Im dont want to be wasting money on ep's for the scope I have now if they wont be any good for the future. 

I have been using the standard 20mm and 10mm successfully, last night I had the cigar galaxy and the spiral near to it, m57 was good and clearly showing structure, bands and moons on jupiter, the disk of mars and the rings around saturn. 

I want to get an eyepiece that will be good for planets and show more detail (such as the grs or the casini division) and another for dso's as im struggling with a few, Id also really like to resolve the double double but I can only get it down once even with the 10mm(90x)

I was thinking of a 6mm and 32mm plossl as Im thinking they would compliment what I have now?

What do you guys think?

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Forgot to add will the 32mm help with viewing dso's or just increase the field of view and not increase the light hitting my eye? 

Ive got no clue how to work out the exit pupil diameter 

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This is the link for Televue's eyepiece calculator that may be helpful.  It does include exit puple calculator

http://www.televue.com/engine/TV3b_page.asp?id=212&plain=TRUE

My preference is for eyepieces that have a wilder field of view and i prefer the Ethos with the  100 degree fov.

this is Televue's advice page that may be of help.

My recommendation is to buy the best eyepieces you can afford.  If cared for the will last a lifetime.

Consider a Televue 5mm Nagler type 6 as a starting point  

 

 

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9 minutes ago, Kbooky said:

This is the link for Televue's eyepiece calculator that may be helpful.  It does include exit puple calculator

http://www.televue.com/engine/TV3b_page.asp?id=212&plain=TRUE

My preference is for eyepieces that have a wilder field of view and i prefer the Ethos with the  100 degree fov.

this is Televue's advice page that may be of help.

My recommendation is to buy the best eyepieces you can afford.  If cared for the will last a lifetime.

Consider a Televue 5mm Nagler type 6 as a starting point  

 

 

Thanks for the advice. I should of out my budget up which is upto £80 for the two ep's i was initially thinking of possibly getting sw plossls

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I wouldn't get a Plossl for your high magnification eyepiece as the eye relief will be very tight. Instead I would look at either the 7mm Celestron X-Cel LX or 8mm BST Starguider as the absolute maximum for your current scope and as a good match for the 150pl. They are a bit pricey for your budget at £60/£50 new but you might be able to find one second hand at around the £35-£40 price mark. A 32mm Plossl will give you the widest real field of view that you will get out of a 1.25" eyepiece and a 2.5mm exit pupil in your Astromaster and a 4mm exit pupil in the 150pl and so I think be a good match. The other option would be to instead go with the 25mm Starguider/X-Cel LX to get the nicer 60 degree apparent field of view but of course you will then lose a bit of exit pupil (exit pupil = eyepiece focal length / telescope focal ratio).

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At the budget given you are sort of limited to something like the Vixen NPL plossls. the eye relief may be a bit short at the 10mm and shorter focal lengths.

At £49 are the BST Starguiders, you have 12mm and 8mm in those, the 8mm should work although I suspect it could be boarderline, and so may not.

Next, as a rule, are the Celestron X-Cel LX's, think these are high £50's say about £58 from memory. Again 12mm and they have a 9mm

Check out Tring Astro as they do the Altair Lightwave eyepieces at £45 last I looked, Altair do them at £55 so one of those is a possibility. Again if memory is working they do a 6mm and a 9mm (not 100% sure of the 9mm).

Just checked and Tring do not list the 9mm but Altair do, check others like 365Astronomy etc, also Rotherv Valley.

Both BST and Celestron's come in 25mm form, BST and Celestrons also come in 18mm. Looks like the Celestron's are £59 (FLO).

That is the options that I am generally aware of and just one, Vixens, are specifically under the £40 mark, and I do not think all of them are.

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I'm not going to make any more eyepiece suggestions, as you already have some good options above, instead a bit of advice:

Don't just throw magnification at an object, it will also magnify atmospheric distortion.

And don't expect an eyepiece to be the magic bullet. I have a Skywatcher 200, and a 6.5mm Morpheus (giving x154), and last night I struggled to split both components of the double double and I've yet to clearly identify the Cassini division.

As long as you keep realistic expectations, you should always be able to see something amazing regardless of what equipment you use.

keep enjoying :)

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Ok so thanks for all the advice. 

So to change the question slightly; If i bought 1 better quality ep (assume xcels) should I be thinking of a smaller one (for planets, i.e 6-8mm) or a bigger one for dso's?(i.e 32mm). 

What would be best with my current set up? But then again it wont be too long before I get the 150pl (think 8 weeks or so).

Like some one said above 150x is really pushing the little refracter but should be ok with the 150, right? 

I dont really have very high expectations of the 70az but dont want to buy more eyepieces than i need too, and if they work well across both scopes its ideal for me.

At the same time I would really like to start on some of the fainter dso's (galaxies in particular) but i cant help but think I may be wasting my time with the 70az. 

Ive got so many different questions and its quite hard to get across what I want to say on a forum. 

But thanks for all of tour input it definately gives me more to think about

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As someone else has hinted above, it is a mistake to think that increasing the magnification will meet with your viewing needs, it often disappoints I am afraid.  Your best bet is to get an 8mm Explorer/StarGuider or similar and edge yourself in gently.

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Its not that I think magification will improve anything but rather give me a better view of the planets. I would like a lower power piece for dso's 

In aware of the limitations of both scopes and their maximum useful power in optimum conditions

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Be aware that if you do go for the Skywatcher 150pl in the near future, it has a focal length of 1200mm and thus will change the magnifications which you get with your present Astromaster. It will also come with 10mm and 25mm supplied eyepieces and a x2 Barlow.

I find I generally view the planets in the x120 to x180 range - but often find if for example I get good views at x120, I can't necessarily get any benefit by pushing the magnification upwards. This is not a problem of EPs or my telescope, but rather atmospheric conditions which are completely outside my control.

Supplied EPs in the 20-25mm range are often quite acceptable - supplied 10mm EPs on the other hand are sometimes not so good, and this seems especially true of Celestron! If planets are your main interest, I would hold off on the 32mm for the moment and perhaps get a slightly better 8mm which will give x112.5 with the Astromaster and eventually x150 with the Skywatcher - BST Explorers might be a good choice at approx 45-50 pounds.

While a 6mm EP will give a useful x150 on the Astromaster, it will give x200 on the Skywatcher which might be a little too much to use regularly.

 

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1 hour ago, Putaendo Patrick said:

Be aware that if you do go for the Skywatcher 150pl in the near future, it has a focal length of 1200mm and thus will change the magnifications which you get with your present Astromaster. It will also come with 10mm and 25mm supplied eyepieces and a x2 Barlow.

I find I generally view the planets in the x120 to x180 range - but often find if for example I get good views at x120, I can't necessarily get any benefit by pushing the magnification upwards. This is not a problem of EPs or my telescope, but rather atmospheric conditions which are completely outside my control.

Supplied EPs in the 20-25mm range are often quite acceptable - supplied 10mm EPs on the other hand are sometimes not so good, and this seems especially true of Celestron! If planets are your main interest, I would hold off on the 32mm for the moment and perhaps get a slightly better 8mm which will give x112.5 with the Astromaster and eventually x150 with the Skywatcher - BST Explorers might be a good choice at approx 45-50 pounds.

While a 6mm EP will give a useful x150 on the Astromaster, it will give x200 on the Skywatcher which might be a little too much to use regularly.

 

Ideal

Thats just the information I was looking for thanks

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