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Hi all

I’m  new to astronomy so please excuse my naive  language and depth of knowledge.

I have purchased a skywatcher heritage 150P flexitube dobsonian.

i have checked it’s is properly collumated.

the accessories I have are the standard 10 and 25mm eyepieces that came with the scope and I’ve purchased a 2x celestron Barlow, planet filters and a moon filter.

im getting some good views of the moon when using my 2x Barlow plus the 10mm lens (lovely detail of the outer edge of the moon). However, when I try to view any of the planets for example Jupiter, Saturn mars, the most I can see is a small glow . I understand that the view will be tiny, but can I expect to have some detail at all?

ive tried with and without the Barlow  , but still see no detail whatsoever. 
I’ve read that just with the eyepieces I should be able to see some of the lines of Jupiter and be able to make out the ring around Saturn, but alas , not even remotely.

Is there something I might be doing wrong? Any help much much appreciated.

Jill

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Crikey I just looked at your link for the bortle where I live ( at the edge of the Brecon Beacons) and it’s class 4 so that’s probably not good? But yes at least I have mountains at hand ok , so

My first scope is a 150 heritage,and I can assure you that it will give you images similar to the simulations John has posted above. It's not a problem with the optics or your fucussing if you can see

If the 'seeing' is poor, any planet will appear fuzzy whatever your focus , I've found that for me, the best way to try to get focus and find out if the view will still be fuzzy anyway is to concentra

Posted Images

If you are getting a fuzzy disc then perhaps a small adjustment to focus is needed as it should be sharply defined. At the moment Jupiter and Saturn are quite low here in the UK and with the weather lately getting a nice clear view will be down to luck in terms of atmospheric conditions.

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Thanks for this quick reply. It doesn’t seem to be able to focus at all on any of the planets matter how hard I try, it’s just like a really small ball of light that’s a little fuzzy. It simply won’t focus to show any detail at all. I’ve tried on several different occasions now and it’s been exactly the same. No problem with the moon however.

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As dave says you will be at the whim of the atmospherics gods - keep at it, The 150 is a good scope but even under perfect conditions jupiter saturn and mars will be quite small.  

Keep an eye out for  better seeing conditions in the forecasts http://clearoutside.com/forecast/54.89/-2.93 or https://www.meteoblue.com/en/weather/outdoorsports/seeing/london_united-kingdom_2643743 this will give you a better idea of how the atmospherics are.  

How are the light pollution conditions where you are observing? Unwanted stray light will play havoc with the quality of your view-  I have a flexitube too and I made a light shroud for the open centre section from a fitness mat and some velcro- it keeps out the stray light and any body heat that interferes with the view quality-

Keep at it dont give up , if the collimation is spot on you should notice that the quality of the view will vary- I find using the higher maginification of the barlow just washes everything out on less than optimum seeing conditions. Try doing a star test, this will confirm wether the collimation is spot on and to what extent atmospherics are affecting the seeing

 You may improve the quality of your view by upgrading the bog standard eyepieces but as always its more money- I would be inclined to get experience of using and getting the most of what you have , learning the  sky and brushing up your astronomy skills and knowledge- Theres some good youtube videos If the bug is still biting hard you may wish to consider spending more to improve your experience-as always  make extensive use of this site , ask more questions 

 

 

Let us know how you go

J

Edited by jacobingonzo
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That’s such a kind response thank you.

haha I’ve already bought 3 astronomy books so I will get my head stuck into those until the atmospheric conditions are better (thanks for the link).

yes I understand that the image will appear extremely small , and that’s fine, if only I could get it sharper and looking less like a tiny streetlight !

i will take the scope up the mountains next away from the streetlights to see if that makes a difference but it’s just bugging me that the moon is so sharp.

I was even thinking of buying 3x Barlow and a 6mm eyepiece (I think that would be about the limit for the telescope)  but I think if it’s out of focus now, it will still be out of focus then. Hmmm many thanks and I’ll keep you updated...

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No probs Jilly - yes getting to darker skies will always improve your seeing but depending on what your circumstances are you may not be able to up and drive at the drop of a hat - 

look at this light pollution map https://www.lightpollutionmap.info/#zoom=2.71&lat=30.2068&lon=11.7949&layers=B0FFFFFTFFFFFFFFFF  it will show what your current Bortle is (the seeing quality- the lower the bortle the better) and where the closest darker sky sites are- but if you live near a mountain then you are one lucky lady!!!  

Yes I would think at this point a 3x barlow and 6mm eyepiece wouldn't improve the fuzziness until the atmospherics are improved- not saying they won't ever improve your experience but again I would advise restraint until you gain more experience with what you have-otherwise you could spend £100/$150 plus if not much more  and still be disappointed.

Just remember how much closer your eyeball is to the moon than the other planets!!! lol

Oh god yes the books!! Im in wonder reading about black holes and supernovi- there is lots of astronomy stuff on the internet -after all it what we have to do when the skies are cloudy and you just have to scratch that astronomy itch

 

J

 

Edited by jacobingonzo
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Crikey I just looked at your link for the bortle where I live ( at the edge of the Brecon Beacons) and it’s class 4 so that’s probably not good? But yes at least I have mountains at hand :)

ok , so my plan so far is...make a shroud , go up into the hills, make sure it’s collumated as well as possible, wait for better atmospheric conditions, and if all else fails purchase better eyepieces, restrain from giving up, read whilst waiting and have some patience 

Thanks so much all for the advice and links, let’s hope this gets me somewhere :) 

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6 minutes ago, Jilly said:

 

Crikey I just looked at your link for the bortle where I live ( at the edge of the Brecon Beacons) and it’s class 4 so that’s probably not good? But yes at least I have mountains at hand :)

 

Believe it or not class 4 is good in the UK, verging on excellent!!!. 
I wouldn’t bother with the mountains for now, just persevere at home, pick your nights and targets higher in the sky. Start with some easy clusters and obvious things like the Orion Nebula which will be naked eye from your location, without even realizing it you will be learning as you go along

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27 minutes ago, Jilly said:

I just looked at your link for the bortle where I live ( at the edge of the Brecon Beacons) and it’s class 4

Bortle 4 is good enough to rule out ambient light pollution being a significant problem for planets. As others have said, it's more likely to be the low altitude of Jupiter and Saturn, or incorrect collimation, or lack of focus.

1 hour ago, Jilly said:

I was even thinking of buying 3x Barlow and a 6mm eyepiece

Well a 6mm would give you 125x magnification, did you mean that you would be using that with a 3x barlow? 375x would be too much for a 150mm to take. The maximum under ideal conditions would be around 300x, but most times in UK conditions you won't manage that. Especially not with planets close to the horizon. Your stock eyepieces give you 75x and 30x; at 75x you should certainly see Saturn's rings if everything else is OK. If you meant you were considering the 3x barlow with these, that becomes 225x and 90x - that would be more realistic than with the 6mm, but you might consider a decent 2x or 2.5x instead. Or split the difference with this.
 

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30 minutes ago, Jilly said:

Crikey I just looked at your link for the bortle where I live ( at the edge of the Brecon Beacons) and it’s class 4 so that’s probably not good? But yes at least I have mountains at hand

As far as I'm aware you do need to take those maps with a bit of a pinch of salt.  I believe they're partially based on assumed information that may well not be true.  I grew up a few miles outside Crickhowell and my recollection is that it was very dark, though I know things have changed over the years.  Where I am now (about 60 miles due south of the Beacons, as it happens) is also classed as Bortle 4, yet some of the things that are listed for Bortle 3 on the page that the Bortle number on that map links to still apply here, even with my slightly older eyes.  If you're away from the larger towns you may find conditions better than that map suggests.

James

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I've got a skywatcher 150P on Equatorial. Since purchase in September only once have I had good viewing of Saturn and Jupiter with any detail. Conditions in Gloucestershire have just been poor worsening since they've got lower . I upgraded to Bst eyepieces which are stunning elsewhere in sky. I'm resigned to waiting for better conditions

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Thank you everyone. It might be because Jupiter and Saturn are low on the horizon, but I just thought it would be slightly clearer than a ‘fuzzy’ dot of light that just won’t focus into a crisp shape. That may well be my lack of knowledge and experience, something just doesn’t seem right about it.

Matte61, what were your views of Saturn and Jupiter like with your skywatcher 150P on an equatorial mount please? Could you get it to become a ‘crisp round shape’ even if you couldn’t see detail?

I’m going to recheck the collimatination (although I think this is ok.

Thanks for the info on the eyepieces and correct magnification Zermelo, my maths always did need a little work !

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The planets should look something like the images below (excluding the name labels !) through the scopes being discussed here at around 200x magnification. Small but sharply defined disks. The detail visible on the planetary disks / rings will vary depending on the seeing conditions. Experienced observers spending time at the eyepiece can usually pull out a bit more detail. These assume a cooled scope that is in reasonable collimation. Saturn might not show all the moons in the image below - some are faint and hard to spot.

These are not exact simulations but in my experience you should be getting something along these lines:

 

 

 

mars.jpg

jupiter.jpg

saturn.jpg

Edited by John
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Thanks John

those were the kind of images I was expecting, but although the size is about the same , the image is far more fuzzy/hazy like a distant blurry streetlight. I can’t seem to sharpen the image at all by trying to focus it. 
I’ve  tried this with only the 25mm eyepiece on, with only the 10 mm eyepiece on, and then with the Barlow. All to no avail. 
I will recheck the Collmination, but when I looked earlier this seemed ok.

many thanks 

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Focussing on them was no problem although obviously the more magnification used the more crucial it becomes. If I rember correctly best view was via 5mm bst starguider eyepiece. The rings of Saturn clearly defined. At best feint bands on Jupiter of different colours. 4 distinct moons all different colours. ( you could check collimation mines spot on now. Pay attention to getting the secondary mirrors centred and looking as circular as possible under the focusser. I got there with a Cheshire tool fairly easily. Corrections are tiny on those 3 Allen screws. After that getting the black dot central on main mirror is pretty easy . Do allow time for any vibration to settle when changing focus too.Iwould also say don't over magnify expecting to see more and concentrate at first Jupiter looked like a bright disc it took time to tune in and see more.

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Yes thanks Matte 61

I’d be more than happy for now if I can just get a disc shape rather than a fuzz of light. 
I’m hoping this is something as simple as collmination or allowing the telescope to cool down for longer. At the mo I’m not getting anything like are kindly describing.

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I've just looked and realise that the focusser differs between our telescopes .Yours being more basic. One site recommends putting some ptfe tape( the white plumbers tape available cheaply in any diy store) If when adjusting your focus it all feels a bit loose and imprecise a couple of turns of tape around the screw thread could help in making fine adjustments. 

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5 minutes ago, Matt61 said:

I've just looked and realise that the focusser differs between our telescopes .Yours being more basic. One site recommends putting some ptfe tape( the white plumbers tape available cheaply in any diy store) If when adjusting your focus it all feels a bit loose and imprecise a couple of turns of tape around the screw thread could help in making fine adjustments. 

I'm fairly sure I've read people recommending that here, too.

James

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My first scope is a 150 heritage,and I can assure you that it will give you images similar to the simulations John has posted above. It's not a problem with the optics or your fucussing if you can see the Moon looking really sharp , so although checking the collimation , sorting a 'shroud' for the open part of the 'scope , and adding some PFTE tape to smooth the action of the somewhat industrial focusser (I got 2 rolls of PFTE for under £2 P&P included from an amazon 3rd party seller, its something plumbers use loads of , so it's easy to get ) are all good ideas, However, I think  your problem is the atmosphere .

Jupiter and Saturn are both very low in the sky now, compared with back in the summer, which means the light from them to our telescopes has to travel  through a greater thickness of air , and the image is therefore less steady. Even worse if  you have to view above houses where warm air will be rising adding extra turbulence. Plus over the last couple of weeks for me here in Leicestershire the night sky has not been steady, or clear of cloud and mist very often, and when it has it's been so windy the telescope has been battered around . You don't say where you are, but it seems much of the UK has had only short periods of good 'seeing' recently.

I bookmarked this page https://medium.com/@phpdevster/help-i-cant-see-detail-on-the-planets-ac27ee82800   as having a good clear explanation of the problems we are facing..

Have you tried looking at Mars ? It is higher in the sky, so should in theory be less affected by atmospheric factors, and it is visible for hours after Saturn and Jupiter have both set, so you have a greater window of opportunity. Some evenings I've gone out to spend time looking at Mars, seen it bouncing around like a little orange ball in the eyepiece, and given up . Other times when it appeared a bit less lively I've spent two hours just looking , and caught some steady views for a few minutes . It seems like a long time for a short glimpse of surface features, but when you do get to see some detail it feels worth it.

Don't give in, be patient, let the 'scope cool down outside before you use it for at least 15 minutes to avoid swirling air currents inside the tube adding to the problem, and have some alternative targets in mind to look at if the planets are not working out:  for instance, a free enormously detailed PDF book about the Moon can be downloaded here http://alanchuhk.com/

 

 

 

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Thanks all.

I’ve been outside to view (not looking through a window) and have already put pfte tape around the focusser thank you.

Yes, I’ve also tried Mars for a while and this appears fuzzy also- I can go through the whole range of focusing without it becoming a ‘crisp’ disk like shape, not remotely close really.

Thank you for the advice and for the links, I will tKe a good look at these later on today. 
I will leave the scope cool down for longer, although my father did say he left it for around an hour the other night and it was the same.

I was thinking myself that it can’t be the optics if I can focus on the moon. Maybe then it is an atmospheric issue, I will keep trying.

Thanks for all suggestions, with much gratitude.

 

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6 hours ago, Jilly said:

Thanks all.

I’ve been outside to view (not looking through a window) and have already put pfte tape around the focusser thank you.

Yes, I’ve also tried Mars for a while and this appears fuzzy also- I can go through the whole range of focusing without it becoming a ‘crisp’ disk like shape, not remotely close really.

Thank you for the advice and for the links, I will tKe a good look at these later on today. 
I will leave the scope cool down for longer, although my father did say he left it for around an hour the other night and it was the same.

I was thinking myself that it can’t be the optics if I can focus on the moon. Maybe then it is an atmospheric issue, I will keep trying.

Thanks for all suggestions, with much gratitude.

 

If the 'seeing' is poor, any planet will appear fuzzy whatever your focus , I've found that for me, the best way to try to get focus and find out if the view will still be fuzzy anyway is to concentrate not on expecting the planet to snap into sharp detail (as you might expect in a camera lens) but to concentrate on the apparent size of the fuzzy ball : that apparent size is smallest when in focus, so watch the size decrease , and then as you pass the point of focus it begins to increase again, so stop and slowly & gently reverse your turning direction.

Repeat , making finer and finer adjustments until  you find the spot where the apparent size is least, and then decide if it seems atmospheric conditions make it worth continuing.

One of the surprising * things to me as a beginner in this hobby has been finding that as well as how to use the bought equipment , I've had to start to learn how to get eyes and brain trained to make sense of what I'm seeing. For me, this sort of learning is fascinating and rewarding, well worth the time and persistence,

I hope you keep  at it, the rewards are great.

 

*Surprising to me, but I imagine every experienced visual astronomer knows it, but has forgotten they had to learn it for themselves. A bit like how difficult it is to recall back before you learned to read, seeing those black squiggles on the page, but not understanding that each in some mysterious way sort of represents a sound .

 

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Great advice there thank you. Ok I am definitely going to try getting the image to its smallest size whilst focussing  when the next clear night comes along. I will let you know how I get on :) 

I read the link about planet viewing not being much affected by light pollution / city light as the planets are so bright and can even be seen sometimes during daylight. Fascinating 

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