Skywatcher 130P - Misted Mirror - Normal?

[Hangar34]

Hi stargazers,

I'm *very* new to astronomy and therefore am probably asking a rather foolish question, but I'd like some advice if possible...

I set up and successfully used my father's new Skywatcher 130P telescope this evening (newtonian open ended type, with parabolic mirror). After bringing the scope inside and allowing it to warm up after having it out in the cold air, I've noticed that the mirror hasn't dried back to it's fully reflective state. It seems that where the moisture of the cold night air has dried on it there seems to be what I can only describe as a pattern like a wet plastic carrier bag has dried on it...

Is this normal? Will it eventually clear or will the mirror require cleaning/polishing again? It would seem a huge downside to owning this scope if a single use has rendered the mirror unreflective.

Could someone offer some advice please?

Many thanks,

Steve

[John]

Don't worry Steve - that's just condensation from bringing the cold scope back into a warm room. Don't touch it at all - it will clear in an hours or so and the mirror will look just like it used to.

The mirror coatings should last for years of this sort of thing.

Welcome to SGL by the way

No foolish questions here - all good ones !

John

[barkis]

Dewing up of the mirror is quite normal when it comes indoors after being out in the cold night air. Just stand the scope on it's end somewhere safe where it can't be knocked over.

The drying process can take a while, but it will happen. Don't put any cover over the mouth of the tube until the mirror has fully recovered. Also, don't be tempted to dry it with tissues or a cloth or such. Left alone it will be fine.

Ron.

[Ghost66]

my 130pm has misted badly but left to dry is fine

[BrownClaw]

Yep, all perfectly normal. I was out last night too and about 10:30 everything started to go a bit dewy when the moisture in the air started to rise...decided to call it a night and after about 90 mins in the lounge everything was back to normal.

Went out for a while this evening and made the mistake of tracking Capella whilst going into the house for a few minutes, only to have the rain start when I wasn't looking. The scope was pretty much pointing straight up overhead and the primary mirror got raindrops on it but once again, after 90 mins indoors the coating won out and it's good as new The 130P is a tough beast in the wet

[Hangar34]

Phew! - Thanks everyone for your replies and reassurance

True as you say, after around an hour or so the mirror was almost back to normal and the condensation was a nicely contracting patch. I think I was overly worried as it was my father's new scope and I thought I'd damaged it in some way.

I'm very impressed with the scope for the money it cost and have been inspired into looking at purchasing my own. I haven't yet seen any planets, nebulas or even the moon through the scope so I have no idea how they will appear. I think everyone woud like to see 'text-book' quality images that are jaw-dropping, but I think I would have to keep my expectations reasonable.

Would you recommend I also purchase a Sky-Watcher 130P, or should I be looking at something else around the same cost bracket?

Thanks again for the advice - it lowered my blood pressure!

Steve

[Astro_Baby]

Bang for th buck you probably cant get better than the Sky-Watcher 130. Its good scope and for the money probably pretty much unrivalled.

If you had a little more to spend theres the 150PL which is also very good. Most Sky-Watcher stuff is sound and will give decent views.

Lots depends on how much you want to spend and whether you need it to be portable or merely luggable.

[BrownClaw]

Well I don't have any other reference points apart from the Sky-Watcher, as it's my first scope (not counting a small Tascom I had as a kid).

The GOTO mount is a breeze to use, provided you either know the names of a few stars or have access to charts/laptop. One of the problems I have is that depending on the time I'm aligning it, the bright stars in the handset's database are vanishing behind nearby houses, so it's forced me to learn a lot more star names!

As you've already used the scope I won't go into the details of what it comprises, or the 8 batteries you need to power it (recharger is a must!), but regarding 'what you can see', I have the following eyepieces - 25mm Wide Angle, 15mm Plossl, and 10mm. I also have a 2x Barlow.

Using the 25mm on its own, spotting the Andromeda Galaxy is a cinch on a decent night. Using averted gaze, you can see the disc shape. Orion Nebula is also very easy to spot also. I've not looked too much into other DSO's yet, apart from the Dumbell Neb, so I can't really comment - Don't expect to see all the DSO's in the handset data-base, as the handset is shipped with more powerful scopes, and so they're just in there for the big boys

Planet wise, as I've only had the scope for 10 days or so, the only ones I've managed to see are Mars and Jupiter. Jupiter is stunning, even so low down and through so much soup, you will see banding with a 10mm and x2B, and the moons stand out very well.

Mars is still a small, low target when I've been observing, so other than a pinkish disc with a hint of polar cap, I've not had much luck yet.

Plaiedes is an absolute joy to see through the 25mm; icy blue stars against a velvet night, eerie and beautiful.

I'm still experimenting, and I'm sure once I've got another eyepiece or so under my belt, I'll be seeing more and more things, plus of course when the weather clears up

Hope this helps

Jason

[SlipperySquid]

Lovely descriptions there mate

[Hangar34]

Jason & Astro_Baby,

Thanks for the additional advice. I've done some reading today and I can confirm that I think my father made a very wise purchase as the 130P does seem like value for money. I'm tempted by the 150PL, but at nearly twice the price it's probably too far a leap for me at the moment.

As you say Jason, I've used the scope and had some experience of what can be seen already. But your additional comments about the nebulas and planets provides some helpful insight (and persuasion!). My father is telling me I can save my money and borrow his scope anytime, but I know that I'll be itching to run out into the garden with my own before the year is out. you know what it's like, you want your own kit to configure your own way.

Thanks again for the pointers,

Steve

[Astro_Baby]

Well the 130 comes in a great many guises - as an Alt/Az with tracking, Alt/Az with GoTo or just on a simple EQ2 mount - all of the 130s are the same tube and mirror so you cant really go wrong.

I started again with the now discontinued 130PM and its was a fabulous little scope. Still regret selling it one but I had a lack of space to store it.

[BrownClaw]

Forgive my ignorance Astro_Baby, but you mention Alt AZ's with tracking and Alt AZ's with GOTO as separate mounts...but my GOTO does auto tracking...have I misunderstood?

[Ghost66]

the 130pm i have has a motor that tracks the object being looked at so keeps it in view

[Hangar34]

My father was under the impression that the Alt/AZ GOTO mount on the 130P was auto-tracking when he bought it, yet despite poring over the documentation for ages, neither of us could see the specific term 'auto-tracking' anywhere. I burst his bubble by claiming that I didn't think it was and that was only a feature on the more expensive mounts...

...however, I was proved entirely wrong when using the GOTO to point to Aldebaran and then after disappearing inside for several minutes to make a brew finding that the scope was still pointing at said star when I returned

So I think Astro_baby has just made a typo when trying to explain that the 130P comes in a range of options that might be more comfortable for my budget is all.

Steve

[vlebo]

I think this is what AB means

Reflectors - Skywatcher Explorer 130

Reflectors - Skywatcher Explorer 130P SynScan AZ GOTO

http://www.firstlightoptics.com/proddetail.php?prod=SW130PSupaTrakAUTO

[brantuk]

When drying out a newtonian, point the tube downwards so excess moisture can drip off to accellerate the drying process. Light moisture whilst viewing can be cleared with a hair dryer on gentle heat, but don't point dryer directly at a cold mirror or temperature change may crack it. Rather circulate warm air in the tube. Dew heaters can help a lot to extend the viewing session - particularly when doing photography. Once dry the mirror will be fine.

[Hangar34]

Vlebo, I think you are correct, those are the options I assumed Astro_Baby meant too. And thanks BrantUK for the extra advice about drying out the mirror - all useful stuff!

Steve