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Eyepiece for viewing detail on Saturn and Jupiter


stella2

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Hi

 

I have a celestron  nexstar 130 SLT. It can't with a 25mm and 9mm eyepiece. First thing i bought was a skywatcher super deluxe Barlow. It's been great for viewing the moon and the 25mm with the Barlow does a good job of a small but sharp view of Jupiter. I'd really like to get a bigger closer view of Jupiter so that i can see some detail. But the Barlow on the 9mm seems permanently fuzzy. A bit of googling seems to say that the eyepieces aren't great quality. I'd like a suggestion for a high quality eyepiece that i can use on it's own for  planetary viewing. Would be good if the Barlow would work with it too. Focal length is f/5. Anyone got the same scope and therefore tried and tested suggestion?

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Are you leaving the scope outside for 30 minutes before use? This would be best if observing at 100x or more.

Your scope has a focal length of 650mm so with the Barlow this is 1300mm assuming a 2x Barlow. With your 9mm this equates to 144x which is doable on good nights with your scope but at the upper end. On poor nights you might not get a sharp image above 80-100x which would equate to a 6-7 mm eyepiece on its own or a 12-13mm with the Barlow.

Maybe persistence with your current kit for now would reap more reward.

Perhaps also check collimation.

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Hi Stella, and a very warm welcome to the SGL - I think that your question is one of the most asked questions in Astronomy.  The Planets really do need a lot of time at the EP - you just need to observe as much as you can to get the most out of your kit.  As Moonshane says - stick with your current kit - the problem is a whole range of things and a little planning helps - the Planets are best observed when they are at their highest point in the sky - so when they are due South - some times are better than others - take Jupiter , over the last few years she has been very high up in the sky - so then your looking through the least amount of atmosphere - the atmosphere is probably the worst variable in the whole equation.   If you can set your observing times around highest point - then your taking advantage of the better seeing conditions and chances are that you will see the steadiest image - but here again things change over the course of hours - some views are really steady - other times it can just be "washed out" these times - even the largest telescopes show very little detail - so choose your viewing times around highest point in the sky.

Saturn will be very low in the sky from the UK for the next few years - so you will just have to put up with poor seeing here - but Saturn is such a great view you can keep on looking for hours.

Larger telescopes under poor seeing conditions will suffer much more than smaller scopes - so its not all about the size of the scope - Don't let anyone tell you any different - smaller scopes side by side with larger scopes can really perform well - the first thing a lot of observers say is that you really need the largest aperture for Planetary views - this is not always the case - the views just don't get bigger when you increase aperture - yes there is a very small increase of the size of the Jupiter - but not as big as many might think - yes the resolving power helps, but you really need to get the most out of your kit - stick with it - some nights are just a lot better than others and this is down to the atmosphere - just keep rolling the scope out over a few nights and you will soon get the hang of the seeing conditions - some nights you can spend hours at the EP - others, you may just as well have a look at the Moon - Magnificent in all apertures.

 

Paul.

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With 130mm of aperture, you're pretty well limited in image scale.  Trying to increase the image size leads to lower contrast (mushy image) even under the best of conditions.  I've found the only real answer is to increase aperture by buying a bigger scope.

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Hi. I'm a beginner myself but have found using a moon filter has allowed me to see more detail on Jupiter. It's a very bright planet so taking the edge on the brightness can help. It was enough for me to clearly see the banding. A good ND filter is around £16. Alternatively, you can get a variable polarising filter which allows you to control how much light is allowed through. Filters normally just screw onto your eyepiece, you should see a thread in the end of the eyepiece that goes into the telescope. Look for the metal framed filters. They're easier to put on with cold hands :) 

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On 2017-03-23 at 17:20, Moonshane said:

Are you leaving the scope outside for 30 minutes before use? This would be best if observing at 100x or more.

Your scope has a focal length of 650mm so with the Barlow this is 1300mm assuming a 2x Barlow. With your 9mm this equates to 144x which is doable on good nights with your scope but at the upper end. On poor nights you might not get a sharp image above 80-100x which would equate to a 6-7 mm eyepiece on its own or a 12-13mm with the Barlow.

Maybe persistence with your current kit for now would reap more reward.

Perhaps also check collimation.

Very good advice Shane, cooling and collimation are hugely important.

To the OP- we have a SW 130mm Heritage and surprisingly will take all my 3-6 Nagler zoom has to offer ie 3mm. Your scope should do 150x quite easily but as Shane says cool the scope and ensure collimation is on. I would suggest a simple Cheshire collimation tool from FLO. Get the cheaper one it is less "busy" visually IMHO. Once you get to know your scope (if you don't already) then start checking out the other eyepieces. The little Heritage gives some good views with the "poor" stock 10mm, the "Super 25" is actually a decent eyepiece.

https://www.firstlightoptics.com/other-collimation-tools/cheshire-collimating-eyepiece.html

edit: for a good planetary eyepiece I like orthos, tight eyerelief and all. I use a 4mm no problem and a 5mm ortho just might be good for you if you don't wear glasses.

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For Jupiter aim at around 80x and if easy then 100x, but 80x is likely sufficent. Jupiter will not be big but you want detail you say and that likely means dropping the magnification down.

Saturn is smaller in angular size and my best view of that was at 125x but in a refractor, try for the same so a 5mm or 6mm eyepiece. Would not suggest a plossl as you will be wearing it like a contact lens. I use one of the 6mm Altair Lightwaves at 6mm, my 5mm is a BST Starguider. If you decide to go for the 5mm first then half expect it not to work well and so you have to buy a 6mm. (Sods law).

Not sure how the reduction of sharpness in a reflector will hit the result. Those vanes and the secondary reduce things and for Saturn you need sharp.

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Often shorter focal length eyepieces have small eye lenses and minimal eye releif, which can make viewing a bit of a strain. It may work better for you if you use longer focal length eyepieces along with a barlow lens. Using a Barlow, which will not degrade the image, will allow the use of more comfortable eyepieces while allowing you to reach reasonably high powers. You don't have to spend a lot on a good barlow lens The SW delux is very good quality and doesn't degrade the image even in premium eyepieces.

Mike 

 

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I was using 128x on Juipiter last night with my 100mm scope and the image scale and detail were excellent :icon_biggrin:

Mind you, the scope was a Takahashi and the eyepiece a Pentax XW so the optical quality was certainly there.

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Some eyepieces are better on planets than others. The conventional wisdom is that the fewer air glass surfaces inside the better the contrast, so something like a supermonocentric with the minimum of two surfaces is supposed to be one of the best. HOWEVER, before you mortgage the house to buy a set, on a scale of one to ten, the most expensive super eyepiece and a celestron plossl probably score 10 and 9.6 respectively. The difference between a night of good seeing and one of bad on the same scale would be 0 to 10! A better barlow may help a little but a large part is experience. it's hard to believe because in our everyday lives, looking at something longer doesn't make it look any better. but at the eyepiece it's a bit different because we're looking through the mush of the atmosphere teasing out fleeting details and assembling them in our minds to an integrated picture. Looking back at my old notebooks from the 1970s, I was able to see far less with a 60mm refractor then than I can now. For example the drawing below was my impression of the orion nebula when I was 16 compared to a drawing I did recently using the exact same telescope and eyepieces. Better equipment will make a difference, but don't fall into the trap of endless expensive upgrades. Perhaps consider joining a local club so you can borrow different eyepieces and have a look through different telescopes - that will give you a good feel for what's possible. But the Celestron 130 is a perfectly good telescope to get going on :)

 

orion.thumb.jpg.617c27190771a764ca3adf44c20cb77e.jpg

 

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3 hours ago, jetstream said:

I thought those Taks go 100x aperture in inches :grin:

They do but, generally, Jupiter isn't a good candidate for it. Especially with the wind gusting and Jupiter shimmering through the central heating plumes coming from the neighbouring houses :rolleyes2:

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I would say stick to a maximum of x1 per mm of aperture. To me that always gives (conditions permitting) the best balance between detail and contrast.

In addition, make sure your scope is well collimated as poor collimation will rob the view of detail. Also cooled down sufficiently to avoid tube currents.

With planets and our seeing conditions, patience reaps rewards. You have to wait, sometimes quite a while, for those fleeting moments of good seeing. When they come along, detail will pop out at you :smile:

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You might also consider getting a binoviewer.  With two eyes looking at a target, I find I can pick out lower contrast details.  You'd probably need an OCA or 2x nosepiece to bring to focus in your telescope.

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