Sky Watcher P150 Starter Questions & Focuser Wobble

[Wolfen54]

Evening All,

So I brought the wife the Sky-Watcher P150i WiFi  and we now have it up and running but a few questions

1) Do we always have to start the telescope due north and at zero degrees before aligning? (aligning with two stars goes well btw when we do, it’s just the first part of aligning north is a tad annoying as scope throws off compass)

2) Wobble and focusing are a nightmare. Once the object has been located, you try and focus on it. With a 25mm it’s doable just, but the 10mm is horrible and don’t even think of putting a Barlow in. Not only does it bounce around like a buckeroo but trying to get a nice clean focus is almost Impossible. I wonder if the focuser needs to be removed and given a proper clean and degrease because it seems stiffer then I would expect a focuser to be? Wobbling I guess we can’t do much about this as I am on concrete.

Love the telescope but the wobble and focuser are a bit of a kick.

2b) Switching from lens to lens means often having to realign the scope slightly, is this normal?

3) Jupiter is very bright and we struggle to make out bands. I have a few filters like a moon glow, red and yellow but I still don’t see the bands. Moons yes, bands no, and that’s with the jumping around.

4) Andromeda Galaxy looks just like a dusty clump. This normal? 

 

Thoughts and comments welcome, thank you in advance

Edited September 21, 2020 by Wolfen54

[Geoff Barnes]

Hi @Wolfen54
 I'll try and answer your  questions as best as I can.

1. Yes, if you are using a wifi systen you always have to start alignment facing due north.

2. Your focuser will have a small screw directly underneath it which you xan uae to adjust the stiffness of the focus action.

2b. Sometimes a very slight adjustment can be needed after changing eyepieces, particularly at higher magnifications, but it could mean the eyepiece is not seated properly in the housing when tightened.

3. Jupiter can be quite dazzling through any telescope and detail can be hard to detect especially if seeing conditions are poor, and if the planet is low down in the sky. The longer you look the more you will see as your eye adjusts to the brightness. Maybe a polarising filter might help tone it down for you, though I have never used one myself.

4. Yes, most galaxies do tend to look a bit like "dusty clumps" to us visual observers. Again, the longer you look the more you will see.

Hope this helps! 😁

Edited September 21, 2020 by Geoff Barnes

[Alan64]

1 hour ago, Wolfen54 said:

Evening All,

So I brought the wife the Sky-Watcher P150i WiFi  and we now have it up and running but a few questions

1) Do we always have to start the telescope due north and at zero degrees before aligning? (aligning with two stars goes well btw when we do, it’s just the first part of aligning north is a tad annoying as scope throws off compass)

2) Wobble and focusing are a nightmare. Once the object has been located, you try and focus on it. With a 25mm it’s doable just, but the 10mm is horrible and don’t even think of putting a Barlow in. Not only does it bounce around like a buckeroo but trying to get a nice clean focus is almost Impossible. I wonder if the focuser needs to be removed and given a proper clean and degrease because it seems stiffer then I would expect a focuser to be? Wobbling I guess we can’t do much about this as I am on concrete.

Love the telescope but the wobble and focuser are a bit of a kick.

2b) Switching from lens to lens means often having to realign the scope slightly, is this normal?

3) Jupiter is very bright and we struggle to make out bands. I have a few filters like a moon glow, red and yellow but I still don’t see the bands. Moons yes, bands no, and that’s with the jumping around.

4) Andromeda Galaxy looks just like a dusty clump. This normal? 

 

Thoughts and comments welcome, thank you in advance

Does Jupiter appear as this through your telescope...

That through my own 150mm f/5 Newtonian, and at a low-to-medium power; but even at the higher powers, nigh to the highest of which the aperture is capable, Jupiter still appears as a white orb, washed-out, and devoid of detail.

[Wolfen54]

21 minutes ago, Alan64 said:

Does Jupiter appear as this through your telescope...

That through my own 150mm f/5 Newtonian, and at a low-to-medium power; but even at the higher powers, nigh to the highest of which the aperture is capable, Jupiter still appears as a white orb, washed-out, and devoid of detail.

Sure does, that is exactly what I saw earlier!!

 

1 hour ago, Geoff Barnes said:

Hi @Wolfen54
 I'll try and answer your  questions as best as I can.

1. Yes, if you are using a wifi systen you always have to start alignment facing due north.

2. Your focuser will have a small screw directly underneath it which you xan uae to adjust the stiffness of the focus action.

2b. Sometimes a very slight adjustment can be needed after changing eyepieces, particularly at higher magnifications, but it could mean the eyepiece is not seated properly in the housing when tightened.

3. Jupiter can be quite dazzling through any telescope and detail can be hard to detect especially if seeing conditions are poor, and if the planet is low down in the sky. The longer you look the more you will see as your eye adjusts to the brightness. Maybe a polarising filter might help tone it down for you, though I have never used one myself.

4. Yes, most galaxies do tend to look a bit like "dusty clumps" to us visual observers. Again, the longer you look the more you will see.

Hope this helps! 😁

Thank you

1, 3 and 4 Okay thank you

2. Never noticed, something for the morning

2b appreciate zooming Will be needed but to move the telescope slightly?

[Geoff Barnes]

It is not the telescope moving, it is the straightness of the eyepiece in its housing.

If you leave the eyepiece loose, with the screws loose and wobble it around as you look through it you will see how the image moves considerably. So if you change eyepieces and the replacement is not centred in its housing exactly the same as the first one the  image you see will not be in the same position and will need recentering.

[Alan64]

37 minutes ago, Wolfen54 said:

Sure does, that is exactly what I saw earlier!!

 

Thank you

1, 3 and 4 Okay thank you

2. Never noticed, something for the morning

2b appreciate zooming Will be needed but to move the telescope slightly?

Then what you need is what I use: a variable-polariser...

https://www.rothervalleyoptics.co.uk/antares-variable-polarising-filter-125.html

You can adjust and fine-tune the filter, from 2% to 40%, and dim the planet down to where the features and natural colours are then revealed.  During a brief time when the atmosphere steadied, I saw the festoons and whorls, sharply, within Jupiter's equatorial bands, and with my own variable-polariser in place; at about 180x.  

You have to be patient whilst observing.  You can take your eye away for just a few seconds, and you'll miss that glorious sight.

[Wolfen54]

@Geoff Barnes Thabk you @ eye piece. Will ensure they are secure. With regards to focuser, there is no grub screw. Mine is the same as this without the cutout to the side. Would releasing the back two screws (picture 3) work?

http://astro-baby.com/Skywatcher Focuser Tune up/Skywatcher Focuser Tune-up.htm
 

@Alan64 Never knew you could get an adjustable polariser, will have to take a look.

skies don’t look clear for later but fingers crossed!

[Geoff Barnes]

4 minutes ago, Wolfen54 said:

Would releasing the back two screws (picture 3) work?

I'm not familiar with that focuser but I would say just slacken the two screws equally very slightly, probably no more than a quarter of a turn and see how much that improves the tension, it's a case of trial and error really.

[Wolfen54]

Will give it a try thank you

[Louis D]

Try putting anti-vibration pads under each tripod foot to reduce vibration dampening time.  It won't do anything for slop in the mount or focuser, though.

Try shining a bright light on a white piece of paper and stare at it for a while to activate the cones in your fovea and to constrict your iris before looking at Jupiter.  It might help decrease the image blow-out you're seeing.

[Zermelo]

I have this scope too.

1) This has been debated previously on this site, with contrary opinions, but I think the conclusion was that North/level alignment is needed only if you plan to use the Synscan "point and track" facility (which makes sense, because you're not relying on the scope to find the object, but it needs to know how it's oriented so it can follow the sky correctly). But if you do a 2 or 3-star alignment correctly, then the mount can in principle build a complete sky map anyway, even if it wasn't originally level/North aligned. Personally, I always level it anyway and point it in the direction I know is Northish at my regular site. I've also found that, even after doing a 2-star alignment, it improves the goto accuracy if I centre/confirm the location of at least one subsequent target (making sure to nudge up and right at least once, or else the app won't let you do so - and no, it doesn't tell you that). I usually drive the scope from SkySafari during sessions, but will switch back to Synscan to select and confirm an object if the guidance seems to be off - it's normally fine, but it can happen if a tripod leg gets kicked, or if the wifi signal drops.

2) Yes, the focuser is a weak point. It's a budget scope, still great value overall IMHO, but that's one of the places they made a saving. I found the mechanism as delivered was very tight, and I agree that - especially with shorter focal length EPs - the in-focus travel can be very short indeed. The link you have above to Astrobaby's tune-up is the definitive one, it confirms that the two screws underneath can be used to adjust the tightness on the rack. I will shortly be following the whole stripping down routine to see how much difference that makes. Others on this forum have replaced the focuser on the cheaper Skywatchers with better alternatives (e.g. a Crayford for around £90). You might decide that's a bit contrary to the original choice of a budget scope.

The "wobble" is a bit more preplexing though. I've found the 150i to settle quite well after disturbance, and I don't bother with anti-vibration pads, hanging weights from the tripod, etc. The tube is short, and as supplied it is comfortably within the weight capacity of the mount. Forgive the obvious question, but are you sure everything is tightened up fully, e.g. the bracing plate is securely up against the inside of the legs?

3) and 4) nothing to add to the previous comments

[ScouseSpaceCadet]

On 22/09/2020 at 08:21, Geoff Barnes said:

I'm not familiar with that focuser but I would say just slacken the two screws equally very slightly, probably no more than a quarter of a turn and see how much that improves the tension, it's a case of trial and error really.

The focuser is plastic rubbish but it does the job while keeping weight down and makes balancing easier. Following the Astro Baby instructions regarding lubrication, tightening the two screws shown, then with an eyepiece inserted, incrementally slackening a little until you find the sweet spot for you, will improve focusing and reduce image shift.

Swapping eyepieces from lower power to high may require the telescope to be manually adjusted slightly via the app/handset to recentre the object if for instance jumping from 25mm to 10mm. If the increment is smaller, say 6mm to a 5mm eyepiece, then probably not.

There are upgraded focusers available, but they're relatively expensive and require the user to carry out some drilling and cutting of metal.

I've a nice TS-Optics Crayford style 1.25" focuser on my 150i but the telescope tube was bought at a knock down price, as a cheap light weight solution for teaming with different mounts. The extra weight of a focuser upgrade upsets balancing using the side mounted small dovetail bar, so besides the cost, not recommended unless you're willing to also fit tube rings...

My 150i while observing Mars (and Uranus & Neptune)

Jupiter shouldn't be washed out so much, depending on seeing conditions, there should be at least a couple of cloud bands to see.

Check your secondary mirror collimation. It's really easy using a cheap cheshire collimating eyepiece. They're about £10 on Ebay.  Basically insert into the focuser, look through it and make sure the cross hair centre is within the circle at the centre of the primary mirror. If not, adjust the three secondary mirror grub screws slightly until it is. Job done. There's plenty of advice available if you get stuck.

The 150i is a decent telescope, you should be able to enjoy a plethora of objects, especially if you're able to view from rural areas. Perservere and enjoy what the universe has to offer.

 

Edited September 24, 2020 by ScouseSpaceCadet

[Zermelo]

I've just seen this Synscan App User's Manual: https://inter-static.skywatcher.com/downloads/synscan_app_manual_20200825.pdf which I don't remember seeing before (and it's dated August 25th). My own 150i was delivered (less than ideally) with a manual for the bespoke handset and a little slip that said, basically, "you don't have one, so you need to download the app instead".

The app's built-in help has some information, but this pdf has more, including on alignment. Be aware that there are two versions of the app; you can use the "pro" version (which has a few extras) with an alt-az mount, but some of the options specific to EQ mounts won't be relevant.