Which lens for viewing Saturn

[HowardMoon]

Hello Everyone,

I have been enjoying Saturn for the past week or so but don't think i have the best lens(s) for the job and would like some advice.  I have a Celestron 80LCM, A H20mm lens came with it and i picked up a K25mm and K9mm along the way.  I also have an OMNI 2 x Barlow lens.

The 9mm allows me to see the rings of Saturn but no real definition and the view is very small.  It doesn't improve using either the 20mm or 25mm and if i try and use the Barlow, i can't get any focus at all.

Is there a lens (or a number of them) that would give me a decent view of the solar system planets?  I had some good views of Jupiter early in the year but even then, i think they could be better.  When i look at images online that folk have taken, they appear much better resolved and larger than i am able to see...

I am observing from the coast of East Sussex.

Thanks in advance for any advice.

Rob

 

 

[RT65CB-SWL]

Hi @HowardMoon / Rob and welcome to SGL. 

What is your budget? Eyepieces come in various designs & disguises. Once 'we' have your budget; then 'we' can advise further. The ones you have are not super, but they give you an idea what to you are looking at.  

Unfortunately the planets are not well placed at the present time. That means the light photons have to go through a thicker atmosphere before they reach eye. I was struggling lastnight to get a good stable view of Mars with my TeleVue Ranger & Nagler 3-6mm Zoom @160x. 

[Stu]

Hi Rob,

As I see it, your scope is an 80mm f11 achromatic refractor. I’m sure you will get varying opinions about what the maximum magnification is that you can use, but it will be somewhere between x120 and x160 ish depending on conditions.

In case you are not aware, magnification is found by dividing the Telescope focal length (in your case 900mm) by the eyepiece focal length. So, the 9mm is giving you around x100, the 20 and 25mm giving you x45 and x36 respectively, which is why you are seeing less with them.

I would not overdo the magnification, but perhaps a 7mm or 6mm would be worth trying.

Have you checked out the ‘What you can expect to see’ thread by Qualia?

[HowardMoon]

Hi, thats great, just the advice i was looking for.  I will get one of each and see how i get on.   I still have a lot to learn.

Regards,

Rob

[HowardMoon]

@ Brown Dwarf, I have enough in my budget to buy a couple of lens' (although i will use some creative accounting to mask this from the 'supreme ruler' when next we sit to do the house budget) and get the impression that a filter would be a good idea as well.  

 

Thanks again.

Rob

 

[bish]

Good advice above. Also remember you are not likely to see the same detail as images you see online.  Don’t want to dampen your enthusiasm but photos can be a bit misleading.

[John]

The planets will look rather small in the eyepiece even at high power (max useful is around 160x with your scope). Many of the the images you see have been enlarged and most have been subject to processing that brings out more details than the eye can see visually. They are also rather low in the sky currently which does not help in picking out details as has been said !

There are lots of other nice sights for an 80mm scope to focus on though and many do not need high magnification to enjoy

[bish]

As John says there is a lot for you to see. Plenty of bright clusters, some good nebula like the dumbell and orion. Obvious but the moon is fantastic. I used a 60mm frac with 3 set magnifications for years.

[Ruud]

Compared to the Moon,planets seem tiny!

Here's a wee Mars reappearing after being occulted by the Moon:

 

And here a much bigger (yet still small) Saturn:

 

Even things that look small can make a big impression.

[RT65CB-SWL]

4 hours ago, HowardMoon said:

@ Brown Dwarf, I have enough in my budget to buy a couple of lens' (although i will use some creative accounting to mask this from the 'supreme ruler' when next we sit to do the house budget) and get the impression that a filter would be a good idea as well.  

 

Thanks again.

Rob

 

As @Stu & @John have said, 160x is about the maximum you are going to get realistically from your 'scope. As I said my Televue Ranger was being pushed to its limit at 160x, and is 70mm.

There is a of eyepiece range called BST Starguiders. I have never used them, but they will be/are an improvement. Prices start from about £49.00GBP and they have some good reviews here on SGL. Having a sixty-degree FOV is also going to make some improvement. @rwilkey is very knowledgeable about eyepieces, so hopefully he will be along later to offer advice for you.

BTW - the '@ Brown Dwarf... ' that is my status, but I will not hold it against you ? ...your status at present is 'Vacuum' ?

[Mr niall]

11 hours ago, HowardMoon said:

Hi, thats great, just the advice i was looking for.  I will get one of each and see how i get on.   I still have a lot to learn.

Regards,

Rob

I prob wouldn’t shell out on one of each, you won’t notice a huge difference between the two. Just one of either is plenty!

celstron do an omni plossl in 6mm for about £22 that’s a good step up.

[noah4x4]

Here is the  blunt thruth. You might see no improvement except on a handful of days per year when 'seeing' improves.  I have the full Celestron eyepiece kit (which isn't very good) and cheap Celestron Plossls might add nothing.

I have an 8" telescope aperture and (£400) Televue 8mm Delos and (£400) 12mm Delos and (£200) Televue 25mm Plossl and have struggled to enjoy any more detail than you. The problem with some planets that are low near the horizon is you are usually viewing through thick atmospheric soup. Then add light pollution, illumination from Sun; skies washed out by the Moon and viewing can be difficult. My best views of Saturn and Mars are often via the lowest magnification 25mm, albeit therefore tiny.  But then on a rare handful of days "seeing" will improve and you get the view you desire through a more powerful EP. You might have to be patient until Saturn is higher and "seeing" improves.

 

 

[SIDO]

In my small aperture 60-90mm ahcromatic longer focal length 900-1200 & up scopes Saturn, Jupiter and Mars I usually only view about 1 month either side of opposition with two weeks either side of opposition being primetime viewing. Image scale due to planetary distance is one issue while observing too early and too late with the lower magifications. Also as the Earth spins ones location north on it's axis the planets appear lower and lower in the south causing one to look though an ever increasing amount of atmosphere to view them mucking up things more and more as ones position moves north.

In these scopes a 7mm eyepiece is often too much magnification my favorite is an 8.5 60° Konig so imho I would skip a 6mm and focus on high quality designs from 9-7mm and concentrate observations closer to planetary oppositions. These smaller longer focal length achromats are nice but do have their limitations, best of luck with Your planetary observations Howard ? 

[heliumstar]

On 24/09/2018 at 21:11, Stu said:

Hi Rob,

As I see it, your scope is an 80mm f11 achromatic refractor. I’m sure you will get varying opinions about what the maximum magnification is that you can use, but it will be somewhere between x120 and x160 ish depending on conditions.

In case you are not aware, magnification is found by dividing the Telescope focal length (in your case 900mm) by the eyepiece focal length. So, the 9mm is giving you around x100, the 20 and 25mm giving you x45 and x36 respectively, which is why you are seeing less with them.

I would not overdo the magnification, but perhaps a 7mm or 6mm would be worth trying.

Have you checked out the ‘What you can expect to see’ thread by Qualia?

Two days ago I was viewing Saturn with Vixen A80M sitting on top of Skywatcher AZ4 mount. Going from Baader zoom to 7mm eyepiece and then on to Vixen SSW 3.5mm. While image dimmed slightly the Saturn was still pleasant at 260x. I was really surprised because even 80ed didn't take 3.5mm as good as the simple 80 achro. The sky was unusually still though just at that moment. So for those short moments it's still worth to have that kind of magnification at hand.

[Stu]

3 minutes ago, heliumstar said:

Two days ago I was viewing Saturn with Vixen A80M sitting on top of Skywatcher AZ4 mount. Going from Baader zoom to 7mm eyepiece and then on to Vixen SSW 3.5mm. While image dimmed slightly the Saturn was still pleasant at 260x. I was really surprised because even 80ed didn't take 3.5mm as good as the simple 80 achro. The sky was unusually still though just at that moment. So for those short moments it's still worth to have that kind of magnification at hand.

The Vixen has very nice optics in it so would probably cope with higher mags better. That said, x260 in an 80mm scope is a 0.3mm exit pupil, my floaters would show up horribly at that sort of level, it sounds like you are fortunate enough not to suffer from them? 

[heliumstar]

8 minutes ago, Stu said:

The Vixen has very nice optics in it so would probably cope with higher mags better. That said, x260 in an 80mm scope is a 0.3mm exit pupil, my floaters would show up horribly at that sort of level, it sounds like you are fortunate enough not to suffer from them? 

The floaters and I are friends as well. I see them but interestingly enough I see them less in 3.5mm Vixen SSW than in Skywatcher 7mm planetary when viewing Saturn. On Jupiter it's a dance though. It also depends on the day I guess. Sometimes they are jumping around like crazy and other days I can hardly spot them.

[Stu]

1 minute ago, heliumstar said:

The floaters and I are friends as well. I see them but interestingly enough I see them less in 3.5mm Vixen SSW than in Skywatcher 7mm planetary when viewing Saturn. On Jupiter it's a dance though. It also depends on the day I guess. Sometimes they are jumping around like crazy and other days I can hardly spot them.

That's strange, in theory it should purely be a factor of exit pupil, but who knows what other effects come into play

[SIDO]

(Two days ago I was viewing Saturn with Vixen A80M sitting on top of Skywatcher AZ4 mount. Going from Baader zoom to 7mm eyepiece and then on to Vixen SSW 3.5mm. While image dimmed slightly the Saturn was still pleasant at 260x. I was really surprised because even 80ed didn't take 3.5mm as good as the simple 80achro. The sky was unusually still though just at that moment.)

Wow I wouldent sell that 80mm achro, 200X is the best I've ever done so far on the Moon with my f11 90mm x 1000mm achro in well over 3 years of pushing and it only happened once as well this is my best achro optically in this class and is my benchmark scope for comparing other achromats. With a 3.5mm in this scope though I would be seeing a snakepit of floaters and blurry images...but I am 54 years old.

[bish]

9 minutes ago, SIDO said:

With a 3.5mm in this scope though I would be seeing a snakepit of floaters and blurry images...but I am 54 years old.

Glad I"m not the only one. Floaters are a real pain these days.

[heliumstar]

24 minutes ago, Stu said:

That's strange, in theory it should purely be a factor of exit pupil, but who knows what other effects come into play

Stu, I am all for theory but with me the greatest effect is tiredness.

[SIDO]

16 minutes ago, SIDO said:

(Two days ago I was viewing Saturn with Vixen A80M sitting on top of Skywatcher AZ4 mount. Going from Baader zoom to 7mm eyepiece and then on to Vixen SSW 3.5mm. While image dimmed slightly the Saturn was still pleasant at 260x. I was really surprised because even 80ed didn't take 3.5mm as good as the simple 80achro. The sky was unusually still though just at that moment.)

Wow I wouldent sell that 80mm achro, 200X is the best I've ever done so far on the Moon with my f11 90mm x 1000mm achro in well over 3 years of pushing and it only happened once as well this is my best achro optically in this class and is my benchmark scope for comparing other achromats. With a 3.5mm in this scope though I would be seeing a snakepit of floaters and blurry images...but I am 54 years old.

I just checked, I was using a 9.7mm plossl and 2x barlow for 206x and the moon was waxing at 63%.

[heliumstar]

I just did a quick session again on Saturn. The scope easily takes 260x. There is a slight hint of degradation when going from 7mm to 3.5mm but overall very pleasant image - confirmed by better half as well!

Rob, definitely worth trying some shorter eyepiece. 7mm, 6mm like Stu said earlier in thread and even shorter!

[Stu]

34 minutes ago, heliumstar said:

Stu, I am all for theory but with me the greatest effect is tiredness.

Interesting, haven't necessarily noticed that, but we are all different.

I have switched to using binoviewers for high power viewing of planets, the moon and sun in order to keep my floaters under control when viewing with a 4" scope.

[Stu]

4 minutes ago, heliumstar said:

I just did a quick session again on Saturn. The scope easily takes 260x. There is a slight hint of degradation when going from 7mm to 3.5mm but overall very pleasant image - confirmed by better half as well!

Rob, definitely worth trying some shorter eyepiece. 7mm, 6mm like Stu said earlier in thread and even shorter!

Whereabouts are you heliumstar? Sounds like you might be further south than the UK? I have a pretty decent 4" apo and Saturn will not regularly take x260 at its current low altitude, even if my eyes could!

 

[heliumstar]

I am in Borehamwood. Two days ago and today surprisingly black sky

What is interesting is that Vixen is sharper than Starwave 80ed I would never believe it until I saw it. And 80ed is sharp, very sharp! When 80ed stops at around 120-130x the Vixen just keeps going.....