CPC Eyepieces

[Georgefleet]

I was going to post this in the beginners section but l figure l need some advice from the “experts “ 

l have just purchased a Celestron CPC 925 Deluxe version and l need some advice on which eyepieces to get.

l want to see the planets and also deep space the only eyepiece l have is the Celestron luminous 23mm that come with the telescope .

[Louis D]

Being an f/10, I wouldn't go below 8mm due to exit pupil considerations.  If you have somewhat steady seeing, you should be able to use powers between 90x and 175x with that scope on planets and still have good contrast.  That equates to 26mm to 13mm.  That 23mm will certainly be a good start at 102x.  I would consider getting a 12mm to 16mm eyepiece to complement it on nights of good seeing.  I'd have to know your budget to go any further with recommendations.  That, and your need to compensate for astigmatism in your observing eye when at the eyepiece by wearing eyeglasses.

[Demonperformer]

Agreed. 100x is reasonable for most viewing nights. You will generally see more on a small bright image than a big faint one, so avoid "magnification fever". The other thing to bear in mind that you need to train the eye to "see" rather than just "look at" and the amount of detail you see will be as much (or more) dependant on how you have developed this skill as the magnification.

[RT65CB-SWL]

It may be going against the grain and cause upset and unrest amongst some SGL'ers, but a zoom e/p may help you find the 'sweet-spot' before getting a prime e/p. The disadvantage to using a zoom e/p is that the FOV is/can be lower at a higher magnification.

Just my 2p worth.   

[Georgefleet]

Thank you for your replies 

l think l will purchase a 13mm as my next eyepiece 

The Scope come with a Celestron luminous eyepiece is this a good choice of eyepiece or are there any brands that you could recommend 

at a similar budget.

[Louis D]

3 hours ago, Georgefleet said:

Thank you for your replies 

l think l will purchase a 13mm as my next eyepiece 

The Scope come with a Celestron luminous eyepiece is this a good choice of eyepiece or are there any brands that you could recommend 

at a similar budget.

Again, what is your budget?  The 15mm Luminos is supposed to  be pretty good for the money and one of the best of the line.  At 13mm, there is the APM HDC-XWA which has a much better corrected 100° apparent field of view (AFOV) than the Luminos's 82°, but it costs a lot more.  There's also the 16mm TS-Optics UWAN which is supposed to be better corrected than the Luminos for about the same money and AFOV.  Explore Scientific markets a 14mm 82° eyepiece for somewhat more than the Luminos/TS-Optics options.  Unfortunately, the 14mm is generally considered the worst of the ES-82 line by many folks.

If you need long eye relief due to astigmatism in your eye, the 14mm Morpheus is a good option at 76°.  I have it and it only exhibits a little bit of astigmatism and field curvature in the last 10% of the AFOV.  It is very easy to take in the entire field of view with eyeglasses.  If you have deep pockets, the 12mm ES-92 is an excellent choice, though large and heavy and also good with glasses.

[RT65CB-SWL]

One word... TeleVue - I do have other eyepiece brands and types as well, but for me TeleVue does tend to be the most compatible over a wide range of f/ratios. 

[Georgefleet]

I have had a look at the Televue range of eyepieces but at 3 or4 the price of the Luminous range l think for now l will stay

with the lower priced option more to my budget.

[rwilkey]

On 27/09/2018 at 10:43, Georgefleet said:

Thank you for your replies 

l think l will purchase a 13mm as my next eyepiece 

The Scope come with a Celestron luminous eyepiece is this a good choice of eyepiece or are there any brands that you could recommend 

at a similar budget.

Hi George, I agree, the Luminos supplied is certainly a good ep which I have myself in its previous guise and called Axiom LX.  I love the way the eyeguard raises when you twist the body.  As the Luminos is 82° AFoV I would suggest something similar.  If you like the Luminos then a 15mm is available, but one of my all time favourites is the Explore Scientific 82° Series 14mm which I highly recommend, it costs more than the Luminos but the quality and the views are exceptional, in other words you get what you pay for.  The 15mm gives you 156x and the 14mm gives you 167x, both pleasing magnifications and probably as high as you would want to go given UK conditions.  

Luminos Link: https://www.firstlightoptics.com/celestron-eyepieces/celestron-luminos-eyepieces.html

ExSc Link: https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-82-degree-series-eyepieces.html

Good luck with any choices!

[Owmuchonomy]

My ‘go to’ EP for all my scopes including my 9.25” SCT is my ES 14mm 82’. It is an excellent EP. So I can vouch for the above recommendation.

[Stub Mandrel]

I'll go against what has been said.

For planetary viewing exit pupil is insignificant as there is plenty of light; you have a 9.25" scope and it will be capable of high magnifications of the planets when conditions are right. I've gone up to x550 with my 10" dob and that was with mirror in awful condition - and the view did not turn to mush.

You should be able to get away with a 4mm EP for planets, but you might prefer to achieve this by using a barlow and a longer eyepiece.