Planet View Dissapointing - Please Help

[CosmicRay]

Hi, I'm looking for some help with my scope.

I have a new 200mm, f/6 Orion Europa reflector, and a set of Meade plossl eyepieces down to 5.5mm. I'm quite sure that the optics are collimated correctly and the views of the moon and stars are fantastic. However, I've been trying to observe Jupiter as my first planet and I'm surprised how small the planet looks even with the 5.5mm eyepiece.

It only fills maybe a seventh of the eyepiece view, and although I can make out the two main belts as darker bands on the disk, I can't see any other detail or any colour despite being in-focus. I've tried on three different nights several weeks apart when the observing has been good.

I calculate the magnification to be over 200x with the 5.5 plossl, so should I be seing a larger image and more detail?

Any help would be appreciated.

[andrew63]

That's to be expected - 200x is a good mag. for jupiter but under certain conditions you may find a mag of 150x will give a sharper image. Planets are small objects so i'm afraid will look nothing like the images you see of it - a pea size is about best! Look out for saturn, which rises later than jupiter, and although a bit smaller - the rings will be a glorious site.

andrew

[Qualia]

I guess good seeing conditions override problems with LP, and assuming collimation is spot on, you'll also find that on average, Jupiter doesn't really need much more than about 140x - 160x.

My 4" frac can easily make out the north and south equatorial belts, great red spot, the equatorial band and the north and south polar regions. If you stick with him, gradually, after 15 minutes or so, Jupiter reveals even more subtler markings especially in the north and south temperate belts and larger markings in the north and south tropical zones. The entire image in the eyepiece is really no bigger than a large pea in the palm of your hand.

Just to add more food for thought, try to view Jupiter as close to the zenith as possible and bear in mind that as a general rule of thumb the brightness of an object will decline as you up the magnification. If I up the mag twofold, say, I'm reducing the image brightness by a factor of four. If I keep on doing this eventually details just disappear. On the other hand, increasing the mag does make detail more apparent, so, as you can appreciate, we're now at a trade-off: will increasing magnification gain more detail even though I'm making the object fainter?

I've found that playing around with this trade-off - dependent on the evening's seeing (as said, I've found that LP doesn't really affect planets) - does make a difference. Even as little as 1mm increase or decrease in the mag - about 10% to 15% difference of magnification - can be quite surprising. You'll probably find that on a decent night your sweet spot is around 140x to 160x on viewing Jupiter and you will probably only be able to push 200x plus on the most excellent of nights.

You've got a wonderful 8" telescope reaching out across the universe some 675,000,000 kilometers and I'm sure - on another better evening - you will be able to see the Great Red Spot, those delicate reddish-brown belts, a darker, greyer hue to the Polar regions, and so on. You'll be able to trace the movement of the Jovian moons and observe their play of shadows over Jupiter in times of transit or of their eclipses by Jupiter's own shadow. From time to time, if you want to enhance that colour of the giant maybe a light blue filter will work nicely, or a Wratten 11 or 12.

If you can, try to sit with Jupiter for a peaceful twenty or thirty minutes or so on your next observation session and I'm certain they'll be moments of great clarity and seeing. I've been following Jupiter almost every night since late July and you do notice that with practice more detail can be tweaked from the planet. Stay with it and as the weeks go by you will notice quite a difference.

[nephilim]

Yep, thats about right, even with bigger scopes the view is small, the bigger the scope the more light is collected so the more detail can be tweaked out (unless of course u can get ur hands on a 24-40" reflector etc ) the actual size of the image stays pretty small, personally I get great views of Jupiter with my 130mm scope & 9mm ep (100x mag) its still tiny but the detail is good & the more time spent looking the more detail seems to come out.

Steve

[Spec-Chum]

Agreed, a 5.5mm eyepiece will give you around 218x which might be a bit much on some, if not most nights.

On my 200mm scope I find about 7mm (171x) to be about optimal most nights.

As a (very) general rule of thumb, try to stick to 150 to 200x mag unless the seeing is exceptional.

[nephilim]

I guess good seeing conditions override problems with LP, and assuming collimation is spot on, you'll also find that on average, Jupiter doesn't really need much more than about 140x - 160x.

My 4" frac can easily make out the north and south equatorial belts, great red spot, the equatorial band and the north and south polar regions. If you stick with him, gradually, after 15 minutes or so, Jupiter reveals even more subtler markings especially in the north and south temperate belts and larger markings in the north and south tropical zones. The entire image in the eyepiece is really no bigger than a large pea in the palm of your hand.

Just to add more food for thought, try to view Jupiter as close to the zenith as possible and bear in mind that as a general rule of thumb the brightness of an object will decline as you up the magnification. If I up the mag twofold, say, I'm reducing the image brightness by a factor of four. If I keep on doing this eventually details just disappear. On the other hand, increasing the mag does make detail more apparent, so, as you can appreciate, we're now at a trade-off: will increasing magnification gain more detail even though I'm making the object fainter?

I've found that playing around with this trade-off - dependent on the evening's seeing (as said, I've found that LP doesn't really affect planets) - does make a difference. Even as little as 1mm increase or decrease in the mag - about 10% to 15% difference of magnification - can be quite surprising. You'll probably find that on a decent night your sweet spot is around 140x to 160x on viewing Jupiter and you will probably only be able to push 200x plus on the most excellent of nights.

You've got a wonderful 8" telescope reaching out across the universe some 675,000,000 kilometers and I'm sure - on another better evening - you will be able to see the Great Red Spot, those delicate reddish-brown belts, a darker, greyer hue to the Polar regions, and so on. You'll be able to trace the movement of the Jovian moons and observe their play of shadows over Jupiter in times of transit or of their eclipses by Jupiter's own shadow. From time to time, if you want to enhance that colour of the giant maybe a light blue filter will work nicely, or a Wratten 11 or 12.

If you can, try to sit with Jupiter for a peaceful twenty or thirty minutes or so on your next observation session and I'm certain they'll be moments of great clarity and seeing. I've been following Jupiter almost every night since late July and you do notice that with practice more detail can be tweaked from the planet. Stay with it and as the weeks go by you will notice quite a difference.

Whoops, pipped at the post- you've a better way of explaining it tho Qualia.

[CosmicRay]

Thanks for your replies - perhaps I've been unlucky with the seeing and was unrealistic to expect a larger image. I'll keep at it and see if I get better results on different days.

[Spec-Chum]

I guess good seeing conditions override problems with LP, and assuming collimation is spot on, you'll also find that on average, Jupiter doesn't really need much more than about 140x - 160x.

My 4" frac can easily make out the north and south equatorial belts, great red spot, the equatorial band and the north and south polar regions. If you stick with him, gradually, after 15 minutes or so, Jupiter reveals even more subtler markings especially in the north and south temperate belts and larger markings in the north and south tropical zones. The entire image in the eyepiece is really no bigger than a large pea in the palm of your hand.

Just to add more food for thought, try to view Jupiter as close to the zenith as possible and bear in mind that as a general rule of thumb the brightness of an object will decline as you up the magnification. If I up the mag twofold, say, I'm reducing the image brightness by a factor of four. If I keep on doing this eventually details just disappear. On the other hand, increasing the mag does make detail more apparent, so, as you can appreciate, we're now at a trade-off: will increasing magnification gain more detail even though I'm making the object fainter?

I've found that playing around with this trade-off - dependent on the evening's seeing (as said, I've found that LP doesn't really affect planets) - does make a difference. Even as little as 1mm increase or decrease in the mag - about 10% to 15% difference of magnification - can be quite surprising. You'll probably find that on a decent night your sweet spot is around 140x to 160x on viewing Jupiter and you will probably only be able to push 200x plus on the most excellent of nights.

You've got a wonderful 8" telescope reaching out across the universe some 675,000,000 kilometers and I'm sure - on another better evening - you will be able to see the Great Red Spot, those delicate reddish-brown belts, a darker, greyer hue to the Polar regions, and so on. You'll be able to trace the movement of the Jovian moons and observe their play of shadows over Jupiter in times of transit or of their eclipses by Jupiter's own shadow. From time to time, if you want to enhance that colour of the giant maybe a light blue filter will work nicely, or a Wratten 11 or 12.

If you can, try to sit with Jupiter for a peaceful twenty or thirty minutes or so on your next observation session and I'm certain they'll be moments of great clarity and seeing. I've been following Jupiter almost every night since late July and you do notice that with practice more detail can be tweaked from the planet. Stay with it and as the weeks go by you will notice quite a difference.

Well, what a great post!

[8kids]

Anothing thing to remember is that Jupiter is very far away. :grin:

[pulsar]

Anothing thing to remember is that Jupiter is very far away. :grin:

Yes it's about 400 million miles away from the earth. And Saturn closer to a billion miles

Like all of the above advice keep plugging away and I am sure you will be rewarded for your patience as us astronomers are a very patient bunch of people.

Good luck with it and clear skies to you all

[Marki]

I find that your eye learns to see the detail with practice. I can see way more detail now than I used to a year ago when I started, and I usually use a much smaller scope than I started with. As you keep looking at it you'll soon see more, and over the next nights it beocmes easier again (well, weather permitting of course!). As others have said, Jupiter is one of those targets where less is more sometimes, except on exceptional nights. I typically go for x140 - x180 with my 4" and 5" refractors, and very rarely go over x200 (when I do the image degrades pretty quickly) even with my 8" SCT.

Good luck, take your time and have fun!

[perrin6]

What make and model is the plossl you're using ? Might be worth investigating getting a better one.

Seeing subtle detail on Jupiter is challenging and sometimes impossible if the atmosphere is especially turbulent but it will usually steady momentarily so you have to keep observing for several minutes to maximize your chances of seeing all that is there.

[CosmicRay]

What make and model is the plossl you're using ? Might be worth investigating getting a better one.

All my eyepieces are from the Meade 5000 range. As I mentioned, the lunar and other views I get are outstanding - very crisp and clear, but Jupiter just seems tiny and with no detail at all apart from the two bands (and no colour). Like a pale pea held at arms length! Even the bands are just two grey lines, no detail in them. I thought I'd see a bit more with a 200mm scope.

[todd8137]

Am a fraud that's it but could you not see any detail on it I had a 300p and the planets were sma,, in that get. Web cam in the scope nd track maual

pat

[Astro Imp]

Qualia that is a great explanation of what to expect and how to observe planets.

[andrew63]

That 5.5mm meade plossl is by all accounts very sharp - you will see more detail as the wise advice from above suggest - when your eye is more 'trained' in the art of observing - if we get enough starry skies that is!

andrew

[andyboy1970]

As said above, as a new observer it takes time for your eyes to become accustomed to looking at very faint/low light levels, but as you get more used to it you start to see more detail.

The amazing fact is that the light your seeing is actually reflected sunlight that has traveled from our Sun to Jupiter then some (not all) is reflected back to us so its traveled about a billion miles.

Ps. a blue filter sometimes helps bring out the detail.

[kirkster501]

Also realistic expectations required too. Some, like my wife, expected to see a Voyager type image when looking through the scope. "Is that it?" was what the silly mare said the other night when I invited her to take a look.

[Space Dragon]

Also realistic expectations required too. Some, like my wife, expected to see a Voyager type image when looking through the scope. "Is that it?" was what the silly mare said the other night when I invited her to take a look.

"Is that it?"..........I like it.

My Mrs fakes a yawn everytime I talk about astronomy........that's a bit rich too.....

[CosmicRay]

Thanks for the advice.

I was expecting something like the larger attached view, but what I get is the smaller view with the 5.5 plossl (not actually my image, but the same as I've been experiencing). If that's the best I can expect from the scope then that's all I can hope for I guess.

[TonyD]

Well, what a great post!

You beat me to it! I was going to use those very words, Spec-Chum.

Rob, you have me counting the days here until I can go to exploring Jupiter.

Thanks mate!

Tony

[acey]

I have a new 200mm, f/6 Orion Europa reflector, and a set of Meade plossl eyepieces down to 5.5mm. I've been trying to observe Jupiter as my first planet and I'm surprised how small the planet looks even with the 5.5mm eyepiece. It only fills maybe a seventh of the eyepiece view. I calculate the magnification to be over 200x with the 5.5 plossl, so should I be seing a larger image and more detail?

Jupiter currently has an apparent diameter of about 45 arcseconds (according to the link below). At a magnification of x200 that will give you an image with a diameter of 9000 arcseconds = 2.5 degrees. (Doing it more exactly, current diameter is 45.2 arcseconds, magnification with the 5.5mm plossl is x218, image diameter is 2.74 degrees)

The image you're seeing in the scope is more than five times the diameter of the full moon seen with the naked eye. So why does it look small?

First think how big the full moon looks. Near the horizon, the full moon looks big, but seen overhead it looks smaller. That's because of the way our visual system works: location markers on the horizon make us interpret the moon as distant and therefore inherently big, while one without surrounding markers is seen as being closer and therefore inherently smaller, even though the image is exactly the same size.

In a telescope we are apt to intepret the object as being small and close (people talk about planets looking "pea sized" - completely meaningless unless you know how far away the pea is). So the answer is somehow to retrain your visual system, or else get used to it and don't expect it to look like a big photograph held at arm's length. Concentrate on detail, not size.

Incidentally, your perception is that Jupiter fills a seventh of the field of view, but if you're using a plossl with an apparent field of about 50 degrees then Jupiter is filling only about a twentieth of the field. Again it illustrates how our visual perception can often be at odds with what we're actually seeing.

As to detail, this can be washed out for various reasons, such as excessive stray light and internal reflections within the telescope or eyepiece, or could just be a result of over-magnification and excessive expectation. Give it time and see if you can raise your own observing skills before blaming the equipment. Next time you get the chance, look at the moon with the naked eye and see how much detail you can detect.

http://www.skyandtel...ascript/jupiter

[perrin6]

I was expecting something like the larger attached view, but what I get is the smaller view with the 5.5 plossl (not actually my image, but the same as I've been experiencing). If that's the best I can expect from the scope then that's all I can hope for I guess.

Never mind the size, feel the quality ! (ie. it's the detail that counts )

[Catweazel]

I was expecting something like the larger attached view, but what I get is the smaller view with the 5.5 plossl (not actually my image, but the same as I've been experiencing). If that's the best I can expect from the scope then that's all I can hope for I guess.

Well, my experience of Jupiter is more like the smaller image that you posted. With a lower powered EP it is even smaller but much sharper and more detailed. A lot of the time I use a 10mm EP in my 120 Frac, which is only around 100x mag, but I find that it gives a very clear image.