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kroy

Skywatcher 200p and Jupiter ... What's my mistake

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I have a skywatchers 200p and on a clear night took it out with high expectations... Moon was awesome and clearly focused... I used my 25mm and 10 mm eyepieces for this ... Later I wanted to see Jupiter and all I could see was a tiny brown spot (though focused) and two of its moons ... tinier dots with my 10mm... I was expecting to see more details than that ...at least bands ... The only reason I can make out it was Jupiter was because I was pointing towards Jupiter on my goto and absolutely no other reason.

What am I doing wrong here!!!

Highly disappointed!!!

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At 120x you should have seen more then a brown dot, a small bright disk with no detail at least. :eek: :eek:

If you used the 25mm (48x) then a very bright tiny disk with no details.

None of the planets are "big" so do not expect images that fill your entire field of view - many do.

The reason I say "no detail" is often because a 200P collects so much light that the image just appears too bright and details disappear in the glare - but it would be bright and you do not mention that.

I have seen banding at less then 50x and less and as said it is bright.

Last nights sky was not clear, the moon was visible but there was a high mist that was messing things up, so some detail would be lost.

Other then saying drop an 8mm BST or a 7mm or 9mm X-Cel in I cannot think of much.

But Jupiter is not a tiny brown spot and that is the main puzzle, even in 8x42 binocular's it is a small bright disk.

No chance you had 3 moons and no Jupiter in view?

Seems unlikely.

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Planets are a bit underwhelming observed through a 200p. It's an instrument better suited to fainter, deep sky objects of large apparent size. Even so Jupiter should look better than a small brown spot. In good seeing I use my 10mm eyepeice with a Barlow lens giving 200x magnification. When I give myself time to get my eye in, the bands and even the great red spot become clearly visible.

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Planets are a bit underwhelming observed through a 200p. It's an instrument better suited to fainter, deep sky objects of large apparent size.

Why do you say that and what instrument would be better? I have found an 8" to be capable of excellent planetary views. A bit dim at higher powers, but still excellent. When the seeing is good, then even more aperture definitely helps.

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I find that Jupiter is best observed over a relaxed period of time. The longer you spend the better you will see.

However, simply put, the supplied 10mm EP is not the best in the world and if you add in the 2x barlow then you really need to spend time.

Focussing can be an issue, try to get the Jovian moons as bright points, at this the planet will be in focus.

Seeing conditions also play an important role, here last night was hopeless with a bank of fog rolling in and high astmospheric humidity.

Local light pollution will also be a problem.

At the moment, Jupiter is reasonable at what would be about 4am your time. Much earlier and it is still low in the sky so you would be looking through quite a bit of clag towards the East.

Realistically, when eveything is right, you should make out some banding details and maybe the GRS if things are really good even with the 10mm EP.

Just 'never' expect to see views that resemble any image you have ever seen, visual observing doesn't work like that with these telescopes. Even a very cheap webcam will provide far better images when correctly used and processed.

PS, Jupiter is such an easy target, why not try to hit it manually through the finder scope and then switch on the motors for tracking? Brown blob is a bit odd.

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oh you should def see banding when you look at Jupiter with the 10mm..sometimes if you look after being in the house with lights it takes a wee while for your eyes to adjust

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This recent thread covers similar issues I think so you may find some useful advice in it:

http://stargazerslounge.com/topic/230624-problems-with-magnification/

On initial examination the detail on even the larger planets is limited and somewhat subtle and their disks small in the eyepiece. Even famous features such as the Great Red Spot don't jump out at you until you take time to really study the planet. Even with my 12" scope and top quality eyepieces the initial impression of Jupiter is usually a pale cream slightly oblate disk with a couple of cloud bands on it. Gradually after careful study and seeing conditions allowing, more detail is revealed but you have to work at it !

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Why do you say that and what instrument would be better? I have found an 8" to be capable of excellent planetary views. A bit dim at higher powers, but still excellent. When the seeing is good, then even more aperture definitely helps.

I can only state my personal experience of planetary views through the 200p, which sadly I would not describe as "excellent". OK on occassion and definitely worth spending time at the eyepeice to squeeze the most out, as stated elsewhere here. A bit of averted vision can help too to help make out polar ice caps on Mars and similar.

What instrument would be better? I have no personal experience of other telescopes, so it's difficult for me to say. Several reviews on line suggest that high-end refractors are good for planets because of their contrasty views. I know a couple of amateurs who concentrate on planetary work and both use catadioptric instruments for their wide aperture and long focal length.

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What instrument would be better? I have no personal experience of other telescopes, so it's difficult for me to say.

Ah... I see. I think you're under-selling the 8" as a planetary instrument in that case. They can be absolutely excellent if, in common with other designs, the optics are good, they are cooled down, and they are collimated. This is all that really matters. I know we spend a lot of time here debating optical designs and what is better for what object, but in reality the aperture, the quality of the optics, and how they are set up likely makes more difference than the design in most cases.

Nice short focal length eyepieces are now available, so there's no compelling need for the long focal length of a cat. In addition, you're getting a large CO with a cat. Other than the diffraction spikes, the planetary surface views through a Newtonian should be as contrasty as a refractor of the same aperture. COs below 20% have no noticeable effect on contrast and this becomes even less important at larger apertures when the Airy disk is already much smaller than seeing can support.

Edited by umadog
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Without being there on the night, it's hard to give definitive suggestions beyond 'have you got the focus right?' (which you say you have), and 'are you sure you're pointed at Jupiter?' (again, you think that's not the issue).

So I'll give you my impressions of planetary viewing (Jupiter in particular) through my SW200p Dob...

I now have upgraded my eyepieces, but I'll talk about my experiences with the stock 25mm, and 10mm EPs that come with this scope.

I found both the EPs gave reasonable views of Jupiter, although the 10mm EP is the inferior of the two in terms of viewing quality (but by no means junk). The first time I got the scope out I had Jupiter in mind, and it didn't look too great. The reason for this was that the scope had not had sufficient time to cool, and was affecting the views quite a bit. After letting the scope get down to ambient temperature things improved nicely. In the 25mm EP Jupiter is very small, but is a definite disc, with banding visible. In the 10mm, the image is a bit larger, but far from fills the field of view. With those two EPs I swapped around depending on conditions which view I preferred, the smaller, but sharper 25mm, or the slightly larger, but less clear 10mm.

Either way, you need to give it time. It's been mentioned above, and I find it really is true... the longer you look at this small disc, the more you observe. The moons will always appear as just bright dots, never as a disc or with any features visible.

Persevere, try again on another night, and take time to soak up the details, and experiment with both the EPs.

So double check: the focus; what you are looking at; scope is cooled; the viewing conditions; the amount of time you give this planet at the EP.

I hope that helps a little! And remember you can always try and get some local help at an astro society or similar.

Clear skies :)

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From experience I would say that 'seeing' and EP's are more important than the type of scope you are using up to a point. That point being that all things being equal a large (8" upwards) SCT will give better planetary views. This is seen out with the best planetary imagers using 12" and 14" SCTs.

On a good night I have had good planetary viewing from reflectors of 114mm aperture upwards even with mediocre EPs. My best experiences have however been with a C8 pushing magnification over 200x with a 7mm orthoscopic EP. The standard 'Super 10mm and 25mm Celestron and Skywatcher EPs are junk and should be replaced as soon as funds permit.

I now have a SW 250 Dob so 'seeing' permitting will be able compare the views through this with the C8 and report back.

Another factor not mentioned is ease of viewing. I could set my C8 Ultima tracking planets and just leave it running for hours without intervention. This is not possible with a Dob and may detract from 'getting your eye in' on the subject planet as you constantly nudge and re-compose in the EP.

Paul

Edited by Polar Bear

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Another factor not mentioned is ease of viewing. I could set my C8 Ultima tracking planets and just leave it running for hours without intervention. This is not possible with a Dob and may detract from 'getting your eye in' on the subject planet as you constantly nudge and re-compose in the EP.

This is definitely true. I too see more detail with tracking. The seeing fluctuates all the time and so you have a greater chance of capturing the rare sharper moments if you can just sit and stare.

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Tiny Brown spot is not what you should be seeing with 200mm aperture, you can make out banding easily enough with half that.

You did remove the whole scope cap and not just the small one to one side of it didn't you? It may sound odd to ask but it's a mistake a lot of people make and since you can still get decent lunar views like that it can take a long time to realise you're doing it wrong.

Sent from my iPad using Tapatalk

Edited by D4N

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I suppose this is really down to what equipment our budgets allow us to commit to this hobby.

I have a 300P and although it's a bit bigger than the 200P, it suffers from the same built in problems. That being it's fast, and at F5 that loses contrast. Flocking the tube makes a heck of a difference, but you will need to be able to take the scope apart, put it back together and collimate it.

The above advice, particularly letting the scope get down to temp makes a big difference. There are loads of mods you can do to improve the performance of this scope for a reasonable outlay. Have a look round the various DIY sections and see what is within your capability.

There are few nights a year when the seeing is good, and the air is still. But when you get a good night the difference is remarkable. Most nights are like looking at a penny at the bottom of a stream, very unstable and disappointing.

I went out with Ibbo a couple of years ago for a couple of hours, and we came away at four in the morning, as the seeing was near perfect. I was watching Jupiter and the movement of the moons and  the GRS. Ibbo suggested a 80A blue filter, and this really brings out the GRS and band detail. I was using a 2" 26mm GSO eyepiece, and a 2" Barlow, giving around 115X. 

It was fairly small, but increasing the magnification took away the detail I got with this combination.

I am hoping that the jet stream will move northwards, this should give us a colder and more stable air mass. This would be great if it could do this for the Xmas holidays when I can get out and not worry about it being a school day.

I hope you get to see Jupiter at it's best, and with the 200P  there are no reasons why you shouldn't get an acceptable look at it. The best time at the moment is early morning when it nice and high and out of the murk.

Good luck and clear skies. :)

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I suppose this is really down to what equipment our budgets allow us to commit to this hobby.

I have a 300P and although it's a bit bigger than the 200P, it suffers from the same built in problems. That being it's fast, and at F5 that loses contrast.

I doubt you'll have contrast problems due to the telescope speed. Your central obstruction is probably under 25%, so it's not especially large in first place and so more or less not noticeable under any circumstances. Remember that cats have COs in the region of 40%. In addition, to see any contrast loss you need to be operating at near the magnification limit of the instrument. i.e. in your case in excess of 400x and probably closer to 600x. In the UK you are unlikely to reach those powers due to seeing. If you had a 6" f/5, things might be different but with a 12" f/5 it's no bid deal.

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I have your scope's little brother and see Jupiter as much more than a tiny brown spot. Jupiter was one of the first objects I viewed with the standard eyepieces and barlow and was really impressed with what could be seen from my own backyard and comparatively modest equipment. 

FYI to give you an idea of size, when the four moons are strung out I can just get them all in the field of view at 150x.

I don't know if conditions for you were the same as here last night but although the moon was visible there was a lot of high cloud/mist severely limiting visibilty.

Keep at it and don't get discouraged, some nights are brilliant but unfortunately many are less so.

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Hi All,

Thank you for all the guidance.My SW 200 is on EQ5 mount.

My telescope was cooled down to ambient temperature for viewing. However I think I three things went wrong here:

1. There was dew in the air which might have impacted the viewing

2. I came out from my room which was pretty much having a lot of light and hence my eyes were not adjusted

3. It was around 11:00 PM and I have heard that you get better views during early mornings.

Will give it a try again.

- Does increasing the magnification (like going to 5mm or 4mm EP - which i will have to buy) helps?

- Since I got a clear shot and properly focused moon doesn't it mean that the telescope is properly collimated ??

- Whats best for astrophotography?

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Also do you think using any kind of filter might help ??

Well I have only one filter - moon filter :(

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Last night I was getting good detail on Jupiter with my 120mm refractor at 130x - 150x so really high magnifications are not required. With your 8" F/5 scope a 6mm eyepiece will give 167x which should show Jupiter well. The planetary disk is not large in the eyepiece even at 200x though but the surface details on the disk can still be picked out with careful observation over a periond of time as has been mentioned.

Personally I don't use a filter but I do wait for Jupiter to clear the horizon by a reasonably large margin because it's much less clear when it's altitude is low, due to atmospheric disturbance etc.

Jupiter is pretty bright so dark adaptation of the eye does not really help. Sometimes in fact people filter it's brightness to help them spot the details easier although I find the eye soon adjusts and starts to pick out the detail from the bright planetary disk.

Jupiters disk is slightly flattened and pale cream coloured overall and the bands appear rust brownish but other tints sometimes emerge under good conditions and when the eye is tuned in.

I'd not worry about astrophotography just yet as it adds a further set of issues / complications which are separate from those involved in visual astronomy.

The picture below gives you a reasonable idea of what I was seeing last night although the moons were in different positions then:

post-118-0-51704700-1417450703.jpg

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A filter won't help in any significant way. Personally, I don't even use a moon filter. Dew will only impact viewing if your mirror is coated in it. Otherwise it makes no difference. You not being dark adapted also makes no difference for Jupiter, which is pretty bright as things go. Light pollution makes no difference for Jupiter either. In fact, some observers believe that remaining light adapted it better for viewing Jupiter. Unless you have a bright light shining directly at you and obviously illuminating everything (e.g. being right under a streetlight), I wouldn't worry.

The higher Jupiter is in the sky, the better. Don't bother until it's above about 25 degrees from the horizon. It should look bright and whitish with two coffee-coloured bands. The small brown round thing you describe isn't right (unless, possibly, it was very low to the horizon). You can't judge collimation by your ability to look at the moon. I suggest you read through one of the collimation guides on line and spend time learning and understanding the steps. Once you do this (and learn how to star test) then you'll know if it's collimated right. As an aside, if it's not collimated right you will likely lose contrast and may also lose brightness if things are really off.

I would expect you would see a nice view at 100x to 150x on most nights. Unless the seeing is horrific, you should be seeing the bands clearly at those powers. If the conditions are good you could expect to hit maybe 250x. But it should look obviously like Jupiter even at 50x. Heck, I can see the planet and moons with binoculars. If you use too much power on a night that can't support it then the image will be worse. You have the gear right now to get a "wow" view of Jupiter. You don't need to spend money on more gear for now, just figure out what's not working.

I wouldn't contemplate AP until you have a really good working understanding of visual observing and understand the gear better.

Edited by umadog
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Jupiter the fifth planet from the Sun ,its maximum opposition magnitude is -2.9, you only see it as the size of John photo, but on a good night you go back home happy.

Edited by Starlight 1

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 you only see it as the size of a penney but on a good night you go back home happy.

A penny viewed from what distance?

The moon is half a degree across (31 arc minutes). Jupiter is at least 30 arc seconds (when it's furthest from us). So if you magnify Jupiter 60x it will appear at least the same size as the full moon does to the naked eye. It'll be twice the size at 120x and so forth. It may feel smaller because the apparent size of an object also depends on distance cues and you don't have any of those through a telescope. Remember that the moon and constellations appear to be much larger when near the horizon, when in fact their size doesn't change.

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The 10mm skywatcher eyepiece is terrible.

I view Jupiter best using a 16mm Maxvision Barlowed to give around 165x magnification.

Another option would be to get a 6.7mm Explore Scientific 82 degree eyepiece to give super wide views at 180x mag.

My first night with the 11mm ES82 coincided with a moon transit shadow across the face of jupiter.

It was amazing, and justifed the expense.

An eyepiece upgrade is likely to be required.

BST's are budget eyepieces for £50.

The 8mm will give you better, clearer magnification.

In the meantime you should still be able to see the banding with the 10mm skywatcher.

I can see two very faint bands in the 3-inch scope at 100x magnification.

If you can't see the bands - fix that first.

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