Planetary

[JohnC260]

Hi all, with regards to Jupiter and Saturn what EP's would be best for observing this on a 90/900 Refractor?

I know I won't see much detail.

[mark81]

Hi John

Have you got any EPs with the scope?  If it's the stock set of EPs then I'm guessing a 10mm and a 25mm.  The 10mm will give you x90 which on a good night should bring out some detail in Jupiter and of course the rings of Saturn...

Or are you lookin to buy some new EPs...?  If so, what budget would you be looking at?  Also, is your scope a refractor or a reflector?

Mark

[chiltonstar]

With my ED80 (80/600) the best views are with a 3.7mm eyepiece or 5mm.

Chris

[JohnC260]

5 hours ago, mark81 said:

Hi John

Have you got any EPs with the scope?  If it's the stock set of EPs then I'm guessing a 10mm and a 25mm.  The 10mm will give you x90 which on a good night should bring out some detail in Jupiter and of course the rings of Saturn...

Or are you lookin to buy some new EPs...?  If so, what budget would you be looking at?  Also, is your scope a refractor or a reflector?

Mark

Hi I have a few others now, the Bresser ones weren’t great and I got some Meade ones which are  slightly clearer, and they were cheap.

So I have:

Meade 4000 9.7mm

Meade 4000 12.4mm

Meade 4000 26mm

Explore Scientific 10mm 70deg

BST Starguider 8mm

And a Revelation 2 x Barlows

My telescope is nothing fancy it’s a Bresser Messier 90/900 it’s a Refractor

Edited July 19, 2019 by JohnC260

[Stu]

I suspect maybe your 8mm BST would be up there with the best of those. Not too much magnification, but enough, and a nice sharp eyepiece

[JohnC260]

I used the BST for the first time the other night for observing the Moon it was fantastic and like you said very clear. 

The Meades are better than what came with the scope they were cheap so I can’t complain. 

Would it be worth getting a 5 or 6mm?

[Stu]

22 minutes ago, JohnC260 said:

I used the BST for the first time the other night for observing the Moon it was fantastic and like you said very clear. 

The Meades are better than what came with the scope they were cheap so I can’t complain. 

Would it be worth getting a 5 or 6mm?

5mm may be pushing it a bit but a 6mm is x150 and may be worth a try for good nights

[JohnC260]

All I can say is WOW!

I set the scope up last night, I have a very small window where Juipter and Saturn go between some large trees, I can't re-locate at the mo as wife is working nights so with kids I need to be within earshot of the house.

I saw Juipter pretty clear, I could see Cassini lines? I think that's the correct term, and I saw four dots I assumed to be some deflection of light but after my friend google confirmed these were moons, I was shocked, I then waited for Saturn and I could see the globe and rings but not much detail but still it's only a 90/900 scope I was impressed.

The 8mm BST Starguider was really nice, I tried my 9.6mm Meade 4000 vs my 10mm Bresser and the Meade is better, same with the 26mm Meade vs Bresser.

If I go for a 6mm I'm tempted by the BST after last nights views, what's peoples opinions on that?

And above all thanks for all the advise I was totally blown away last night, thanks again.

[Stu]

Well done John!

The two main lines on Jupiter are called the Northern and Southern Equatorial Belts (NEB and SEB). The Cassini division is the main split in the rings around Saturn which is a good test of scope and seeing conditions.

You could give the 6mm a go, it should work well under good conditions, but do remember that the planets are low currently (and for the next few years) so you will be looking through alot of atmosphere.

I think a number of places will let you return them if not suitable anyway under distance selling laws,provided they are in as new condition. Worth checking out.

[JohnC260]

Ah I checked and BST don’t do a 6mm, but they do have a 5mm but not sure how well that will play with my 90/900?

Thanks Stu you have helped a lot, like you said it’s low at the moment so I’m getting a lot of haze, so I can’t wait for it to be higher in the skies. 

[Stu]

5mm would be too much I expect. You could maybe try a 6mm ortho of some sort, BCO or BGO if you can find one, nice sharp eyepieces but the eye relief is short. Normally around £50 used. There may be some other suggestions out there too but I've not got experience of them.

Mars should be good next year, higher up at opposition, but then its 2024 before Jupiter gets better as I recall. Slim pickings for a while I'm afraid.

[JohnC260]

ok I will look around thanks Stu, with the 5mm BST I looked at the specs, it says it's ok with F5+ scopes, mines a F10 if that helps?

I was looking at the Baader Ortho Classic EP's.

I heard the 6mm Plossl isn't ideal as the eye relief is so short, reason I said about the BST is the eye relief is really nice.

[Stu]

F10 is fine for pretty much any eyepiece, it is a slow scope and undemanding so you should get decent results even with quite basic eyepieces.

Actually one thing you could try is a Zoom and Barlow combination. I have the Opticstar 7.2mm to 21.5mm eyepiece below:

http://www.opticstar.com/Run/Astronomy/Astro-Accessories-Telescopes-Opticstar.asp?p=0_10_5_1_8_330

And you could combine it with a Barlow such as this:

https://www.firstlightoptics.com/barlow-eyepieces/baader-classic-q-225x-barlow.html which would give you 9.5mm to 3.2mm with the Zoom. In a slow scope, this eyepiece performs really quite well; I was getting results not that far off my orthos last night in my f8, with the flexibility of being able to tune the magnification.

If you managed to pick them up used then you would get a feel for the magnification that work, and then be able to sell on for little loss if you then want a specialist eyepiece at a fixed focal length.

[JohnC260]

Fantastic thanks again Stu

[John]

I use the zoom + barlow combination that Stu highlights above it it does work very well indeed for variable high power observing.