need to get the best lenses for the celestron 8SE

[truk]

First things first I am a beginner. I have the celestron luminous 10mm lens and the stock 20mm that came with  it. I only see the moon amazingly clear though. All the other stars do not seem to be magnified at all, I don't see planets well either. I read somewhere a focal reducer clears up the image is that true.

          I cant focus that well with the Luminos. do I need a wider angle lens, do I need to go >10<20mm? or >20mm. I need a sharper, clearer image and  wider field of view. I need help.

[rory]

Stars will never seem magnified if afraid . They are always pinpoints of light because if the distances involved. If you focus on some stars on a nice clear night , see how sharp and pinpoint you can get them ,that will give you optimum focus at least for general focusing.

That's a nice scope by the way.

[Uplooker]

+1 for what rory says. I would certainly hold off purchasing a focal reducer for the time being, at least until you have more experience of the kit you have

Ian

[michael.h.f.wilkinson]

The 8SE is a very nice scope. I agree with the above advice, plus please note that focusing at 200x with the 10 mm will always be a bit tricky. If you want wider views you need to replace the 1.25" visual back and diagonal with a 2" type (I did that with my GP-C8, which has the same optics as the 8SE, and the result is very nice). Alternatively, you can get a focal reducer to F/6.3. The stock 26mm Plossl that came with my C8 was pretty decent, but I do not know which 20mm your scope comes with. The maximum FOV with a 1.25" EP can be obtained with a MaxVision 24mm 68 deg, which are going for a very good price at the moment. If you are willing to splash out for a 2" diagonal, seriously consider the 24mm 82 deg MaxVision: near-Nagler quality for less than half the price. I have a very similar 22mm Nagler and it is one of the best EPs in my collection. Something between the 20 and 10mm could come in handy (about 14mm). In a 2" diagonal, the Skywatcher Aero 40mm is an affordable choice that gives nearly the maximum field of view, should you want to go that way.

Please note that I kept my basic Plossl EPs (10, 26, and 36mm) with a focal reducer for a long time (>10 years for the 26 and 36mm, 3 years for the 10mm) before I upgraded. I only started replacing them when I started noticing deficiencies in them. I first spent a lot of time at the EP to learn how to tease detail out of the view. Many objects (like e.g. M33 and M101), require some effort to see, although once you have the knack, you wonder why you missed them the first (few, or sometimes many) times. Likewise with planets. Once you get Jupiter in your sights, stick with it, and be patient. Initially, you just see the disc, a few bands, and some moons. As you wait, and fiddle with focus, you will notice that the image is sometimes suddenly a lot sharper, and fine detail appears, to vanish a few moments later. This is due to turbulence in the atmosphere, an effect known as seeing. Picking out galaxies and other faint objects requires practice. You need to use averted vision: looking just next to the object makes it a bit clearer. I am sure I have picked up several galaxies this year with a scope very similar to yours, which many (even seasoned) observers might have missed. Your skills will improve with loads of practice. Better EPs can and do help, but they won't magically transform your views. Much depends on conditions and the observer. The standard EPs are not bad at all, and an F/10 scope is quite tolerant for simpler EP designs, so I would advise against rushing off to replace them. Extending the options at the wide field end is a better idea, and getting a gap filler at 14 is certainly worth considering.

When I did replace things, the 10mm was replaced for visual work with Vixen LV 9mm and 7mm EPs, which have longer eye relief (nothing wrong with the 10mm Plossl in terms of quality, just a pain to use with glasses). When I got my 2" visual back for the flip-mirror used for planetary imaging, I got a TMB Paragon 40mm (now sold under TS branding and as Skywatcher Aero), with 68 deg apparent field of view (FOV). That blew the 36mm out of the water in performance. I added a 14mm UWA from Meade, and that gave almost the same true FOV as the 26mm Plossl, so the latter was replaced with a  22mm Nagler. By then I was hooked on wide FOV, and the rest is history.

[ronin]

The SE8 being an SCT will be about f/10, so something around the 2000mm focal length.

Even with the supplied 20mm you should get planets to be visible as you will have 100x magnification.

I assume that when you say you cannot even see planets you mean blank, that is simply they are outside the field of view.

That sounds like set up and alignment. Suggest you check the data and spend more time when setting the scope up. The SCT's have a fairly narrow field of view so it takes a bit of extra work to get things right - I have a small Mak and they are slightly worse. It is worthwhile getting everything as correct as possible at the start.

Beng a long focal length you have the advantage that eyepieces like plossl's will work well, so if plossls are chosen get a reasonable brand. WIll not say who's as the US have slightly different to us here.

The slight draw back is that plossls have less eye relief as the focal length of the ploss get s shorter, they also tend not to be parfocal so you adjust focus a fair bit as you swap eyepieces.

Next up in cost are the Astro-Tech Paradigms in the US, nice eyepieces and will be good in th 8SE.

Focal lengths: well at f/10 I suggest a 10mm as the shortest, it will give 200x and really more is of limited use. Don't go round thinking that trying for 300x will do anything, it won't. the 200x to 250x range may be useful on Mars, however that is only once a year so don't go mad over it.

Cannot say much about plossl's as the focal lengths available depend on the make. In the Paradigms you need to look at something like 12mm, 15mm and 25mm ( they do not have a 10mm). All will actually give fairly high magnifications, the focal length of your scope causes that. So look at one eyepiece at some time for wider views.  TV plossls follow much the same focal lengths and go up to 32mm and 40mm, they cost more then the Paradigms.

As Mars is slowly coming into view and I will say that 200x and above is probably nexessary then consider the 8mm Paradigm for that. However the only real use for an 8mm on the 8SE will be for Mars.

Be aware that above 200x and sometimes at 200x you will not see much, the atmosphere is the cause of that. If you are in New York City not the state then you will have fairly poor atmospheric conditions - too many building and too much heat.

The only retailers I know of are Astronomics, Ageno and Eyepieces Etc.

In Apil 12 and 13 at Sufferen (NY) is the large NEAF Show. Just April is a long wait.

Also read the manual for something like PEC, a method of enabling the scopen to be a bit more accurate in the movements to an object.

[Sobel]

I've found the X-Cel LX 18mm to be a great EP for my 8SE. MIght be worth a look alongside the other suggestions.

[CodnorPaul]

I have an 8SE but upgraded the mount - have to agree with the above, it is a fabulous scope capable of great views.  I use a hyperion zoom as I don't get on with plossls but that said at F10 there is no reason why you wont get superb views with what you have.  The planets are what this scope was designed for - excellent views of Jupiter, Saturn and Mars easily in its capabilities, and I have glimpsed Neptune and Uranus from dark skies also.  That being said due to its aperture it does well on DSOs as well.

It does sound more like alignment/set up, or collimation issues - not an EP issue.  If you have a local astronomy group near you go and meet up with them - they are normally really friendly and welcoming, and an experience observer can check your set up and collimation, or even let you borrow an EP for a moment to look through before spending the money out and then realising that isn't the issue at all.

[truk]

The 8SE is a very nice scope. I agree with the above advice, plus please note that focusing at 200x with the 10 mm will always be a bit tricky. If you want wider views you need to replace the 1.25" visual back and diagonal with a 2" type (I did that with my GP-C8, which has the same optics as the 8SE, and the result is very nice). Alternatively, you can get a focal reducer to F/6.3. The stock 26mm Plossl that came with my C8 was pretty decent, but I do not know which 20mm your scope comes with. The maximum FOV with a 1.25" EP can be obtained with a MaxVision 24mm 68 deg, which are going for a very good price at the moment. If you are willing to splash out for a 2" diagonal, seriously consider the 24mm 82 deg MaxVision: near-Nagler quality for less than half the price. I have a very similar 22mm Nagler and it is one of the best EPs in my collection. Something between the 20 and 10mm could come in handy (about 14mm). In a 2" diagonal, the Skywatcher Aero 40mm is an affordable choice that gives nearly the maximum field of view, should you want to go that way.

Please note that I kept my basic Plossl EPs (10, 26, and 36mm) with a focal reducer for a long time (>10 years for the 26 and 36mm, 3 years for the 10mm) before I upgraded. I only started replacing them when I started noticing deficiencies in them. I first spent a lot of time at the EP to learn how to tease detail out of the view. Many objects (like e.g. M33 and M101), require some effort to see, although once you have the knack, you wonder why you missed them the first (few, or sometimes many) times. Likewise with planets. Once you get Jupiter in your sights, stick with it, and be patient. Initially, you just see the disc, a few bands, and some moons. As you wait, and fiddle with focus, you will notice that the image is sometimes suddenly a lot sharper, and fine detail appears, to vanish a few moments later. This is due to turbulence in the atmosphere, an effect known as seeing. Picking out galaxies and other faint objects requires practice. You need to use averted vision: looking just next to the object makes it a bit clearer. I am sure I have picked up several galaxies this year with a scope very similar to yours, which many (even seasoned) observers might have missed. Your skills will improve with loads of practice. Better EPs can and do help, but they won't magically transform your views. Much depends on conditions and the observer. The standard EPs are not bad at all, and an F/10 scope is quite tolerant for simpler EP designs, so I would advise against rushing off to replace them. Extending the options at the wide field end is a better idea, and getting a gap filler at 14 is certainly worth considering.

When I did replace things, the 10mm was replaced for visual work with Vixen LV 9mm and 7mm EPs, which have longer eye relief (nothing wrong with the 10mm Plossl in terms of quality, just a pain to use with glasses). When I got my 2" visual back for the flip-mirror used for planetary imaging, I got a TMB Paragon 40mm (now sold under TS branding and as Skywatcher Aero), with 68 deg apparent field of view (FOV). That blew the 36mm out of the water in performance. I added a 14mm UWA from Meade, and that gave almost the same true FOV as the 26mm Plossl, so the latter was replaced with a  22mm Nagler. By then I was hooked on wide FOV, and the rest is history.

I have an 8SE but upgraded the mount - have to agree with the above, it is a fabulous scope capable of great views.  I use a hyperion zoom as I don't get on with plossls but that said at F10 there is no reason why you wont get superb views with what you have.  The planets are what this scope was designed for - excellent views of Jupiter, Saturn and Mars easily in its capabilities, and I have glimpsed Neptune and Uranus from dark skies also.  That being said due to its aperture it does well on DSOs as well.

It does sound more like alignment/set up, or collimation issues - not an EP issue.  If you have a local astronomy group near you go and meet up with them - they are normally really friendly and welcoming, and an experience observer can check your set up and collimation, or even let you borrow an EP for a moment to look through before spending the money out and then realising that isn't the issue at all.

do you think that upgrading the diagonal to 2" like your set up will help. I do have alignment issues so i have to look for help on that also. I believe what you said about the eyepiece not being the problem. but the celestron luminous is susposedly good but i dont wear glasses and have some trouble seeing out of it. i get alot of my eye reflecting. the ep included was a 25mm plossl i made an error previously. why do you prefer the hyperion over the plossl? 

[CodnorPaul]

A 2" diagonal will only help when using 2" eyepieces to give a wider field of view - it wont help the focus, nor will it give any advantage on planets or smaller DSOs as they will only occupy part of the FOV.  I like it for the bigger DSOs but the zoom I use is a 1.25" EP so it doesn't add anything to that, and I mainly use the zoom in sessions.  The luminous EP range do get decent reviews, and in that OTA they should be fairly good so I wouldn't think a new EP is the answer - sort your alignment issues out and check collimation.  I changed my mount as I didn't get on with the SE mount and didn't find it very accurate, but there are people that get good results out of them so keep going at it.

Why do I like my zoom - it saves me changing EPs all the time during a session, and in an F10 scope it provides good clear views, also I use it with a 2" nosepiece so I don't have to mess with adapters for my diagonal.  It isn't perfect and I am sure that fixed focal length EPs may give marginally better views - but at the moment I am more than happy with the range it gives me (8-24 mm) and it is one of the better zooms on the market

[truk]

The SE8 being an SCT will be about f/10, so something around the 2000mm focal length.

Even with the supplied 20mm you should get planets to be visible as you will have 100x magnification.

I assume that when you say you cannot even see planets you mean blank, that is simply they are outside the field of view.

That sounds like set up and alignment. Suggest you check the data and spend more time when setting the scope up. The SCT's have a fairly narrow field of view so it takes a bit of extra work to get things right - I have a small Mak and they are slightly worse. It is worthwhile getting everything as correct as possible at the start.

Beng a long focal length you have the advantage that eyepieces like plossl's will work well, so if plossls are chosen get a reasonable brand. WIll not say who's as the US have slightly different to us here.

The slight draw back is that plossls have less eye relief as the focal length of the ploss get s shorter, they also tend not to be parfocal so you adjust focus a fair bit as you swap eyepieces.

Next up in cost are the Astro-Tech Paradigms in the US, nice eyepieces and will be good in th 8SE.

Focal lengths: well at f/10 I suggest a 10mm as the shortest, it will give 200x and really more is of limited use. Don't go round thinking that trying for 300x will do anything, it won't. the 200x to 250x range may be useful on Mars, however that is only once a year so don't go mad over it.

Cannot say much about plossl's as the focal lengths available depend on the make. In the Paradigms you need to look at something like 12mm, 15mm and 25mm ( they do not have a 10mm). All will actually give fairly high magnifications, the focal length of your scope causes that. So look at one eyepiece at some time for wider views.  TV plossls follow much the same focal lengths and go up to 32mm and 40mm, they cost more then the Paradigms.

As Mars is slowly coming into view and I will say that 200x and above is probably nexessary then consider the 8mm Paradigm for that. However the only real use for an 8mm on the 8SE will be for Mars.

Be aware that above 200x and sometimes at 200x you will not see much, the atmosphere is the cause of that. If you are in New York City not the state then you will have fairly poor atmospheric conditions - too many building and too much heat.

The only retailers I know of are Astronomics, Ageno and Eyepieces Etc.

In Apil 12 and 13 at Sufferen (NY) is the large NEAF Show. Just April is a long wait.

Also read the manual for something like PEC, a method of enabling the scopen to be a bit more accurate in the movements to an object.

thank you. i agree with you on the set up issue im 

A 2" diagonal will only help when using 2" eyepieces to give a wider field of view - it wont help the focus, nor will it give any advantage on planets or smaller DSOs as they will only occupy part of the FOV.  I like it for the bigger DSOs but the zoom I use is a 1.25" EP so it doesn't add anything to that, and I mainly use the zoom in sessions.  The luminous EP range do get decent reviews, and in that OTA they should be fairly good so I wouldn't think a new EP is the answer - sort your alignment issues out and check collimation.  I changed my mount as I didn't get on with the SE mount and didn't find it very accurate, but there are people that get good results out of them so keep going at it.

Why do I like my zoom - it saves me changing EPs all the time during a session, and in an F10 scope it provides good clear views, also I use it with a 2" nosepiece so I don't have to mess with adapters for my diagonal.  It isn't perfect and I am sure that fixed focal length EPs may give marginally better views - but at the moment I am more than happy with the range it gives me (8-24 mm) and it is one of the better zooms on the market

since im just starting out and I have a 10mm luminous and the 25mm plossl both 1.25 pieces should I continue buying eps at 1.25" to fill out my range. Or get the 2" diagonal and continue with 2" eps  or even one 2" zoom Since it gives a wider FOV. 

[CodnorPaul]

I dont think you will get a 2" zoom - I believe they are all 1.25" but not 100% sure, mine just has a 2" nosepiece but the actual EP is 1.25".  As for buying 2" or not that is a personal choice - I prefer them, and they feel a lot more solid on the OTA, but the 1.25" EPs are still worthwhile and at the higher mags that is all you will get as there is no benefit to having a 2" EP at say 25mm and lower

[michael.h.f.wilkinson]

For really wider fields, a 2" diagonal is the way to go, and the 2" diagonals will happily accept 1.25" EPs. The alternative is to use a 0.63x reducer, but because that screws into the rear of the scope, between OTA and visual back, switching it into and out of the optical path is so cumbersome, I noticed I did not really do that often. A quick switch between wide field and planetary was near impossible with the reducer (I still have it, but only plane to sue it for imaging.

[rwilkey]

You only really need one 2" widefield ep, so continue with 1.25" and don't go for one or the other only, both sizes are useful to have and use.

[Tinker1947]

In a aid to seeing sharp stars or anything else you focus on one of these will make a big difference.....

http://www.firstlightoptics.com/starlight-instruments-feathertouch/microfocuser-for-celestron-cpc-800-6se-c8edge-8se.html

[brantuk]

Check if your collimation is out or not with a star test. Focus as tight and sharp as possible on a bright star - then take it slightly out of focus, first one way, and then the other. Both sides of focus you should see faint "airy" circles that are arranged perfectly concentric to each other. If the circles aren't concentric then your scope will need collimating.

This should always be done before considering eyepiece purchases as a solution to a problem - or you could just be wasting money.