wulfrun

Minor (constructive) criticism: left-panning your voice sounds odd in headphones. Enjoyed it otherwise:-)

Nothing expensive but postie brought me a 32mm plossl for low-power views in my 150PL. Might be speaking too soon but the skies here are clear, has to be a first if it stays that way...and I may also have jinxed it now!

Not a job for the faint-hearted to DIY it and you need the proper tools and experience. A professional repair may or may not be justifiable and may or may not be possible, depends what it's worth to you too. Decisions, decisions! To be fair, it's not really the fault of the coatings, it's the environmental factors and (lack of?) sealing.

Just bad luck then. Damp at some point then kept in the dark (caps on will do) perhaps. I've cleaned fungus off camera lens elements where it's etched the coatings, so it needs attention pronto if it's not too late already. The lenses I found etched did still perform well though (after cleaning), just to throw you some comfort.

The bottom one is almost certainly fungus and the spots might be spores but hard to be sure. Needs a professional clean ASAP before any (more) damage gets done. Assuming you aren't able/willing to tackle it yourself. Probably not what you want to hear, sorry. I've seen it in camera lenses so I'm reasonably sure. Where has the scope been kept?

Thanks to all. I've pressed the button and a 32mm plossl should be appearing at my doorstep before too long...

Switch-mode supplies contain 2 capacitors, one from one mains terminal to output (positive) and likewise from the other mains terminal to output (negative). The idea is they feed interference away into the mains supply, reducing RF noise. The capacitors are low value, meaning there is no electrocution risk (see below though). There are three consequences, one being that the output "floats" at half mains voltage. Another is that a capacitor failure can place mains voltage on the output - which is why a "fail open-circuit" class of capacitor is supposed to be used. These cost more, so you may find unsafe substitutes in dubious-source gear. The third consequence is in connecting other gear, with an earth and sensitive inputs, to the powered-up gear. It can and does destroy sensitive electronic input circuits as the capacitors discharge the "floating" voltage. Connect all gear first then apply mains, to avoid that risk. Usually not mentioned in the manual!

Thanks for the input, I just wanted to know if a long FL plossl was a poor idea, to be avoided. I'm aware that low magnifications are limited by the 1.25" focuser, in terms of TFOV. I'm more interested in what the gain in exit pupil might bring. @jonathan thanks, yes I know I can "try" it in Stellarium but it doesn't provide a realistic view, just shows me FOV and what is, potentially, in it.

I have a Skywatcher 150PL (1200mm focal length and f/8) for which I have a selection of EPs but I think I'm maybe lacking a low-power one. The longest I have (not counting a zoom) is an ES20mm/68-degree, which gives x60 and a TFOV of 1.13 degrees. If I bought (say) a 32mm plossl, I'd gain a bigger exit-pupil, slightly more TFOV (1.21 degrees) and a lower magnification of x38. Ultimately, I believe the greatest TFOV is limited by having a long F/L and a 1.25" focuser, which I do not plan to fiddle with. Is this a sensible and desirable purchase? Considering a 32mm plossl isn't big money (£25-30)...or are there better ideas from the knowledgeable? I do have another scope if I need wide FOV but I tend not to have two scopes out at the same time, for various reasons.

I had the 150PL out last night, it was a little hazy but I bumped the scope a few weeks ago and I had to re-collimate it (my first attempt), so I was itching to see if it was job well done. Started off on the moon with a 20mm, 16mm, Hyperflex zoom and 2x focal-extender to hand. Apart from the interruption of passing dense cloud, it looked really clear, even at 150x (16mm+FE). I aimed at polaris for a star-test (looking good), I moved on to M42 for a bit and then had a wander around the Plaiedes with the 20mm in. Then I decided to go back to the moon, since the whole sky was looking likely to cloud over completely. I put one half of a polariser on the FE and the other half on the 16mm (well, so I thought). Popped the EP in and turned to adjust the brightness...ahh, why is my view zooming? I'd inadvertently put the Hyperflex zoom in, it's about the same shape as my UWA 16mm! Oh well, it's in there so let's just see. Got all the way down to 7.2mm and the view stayed crisp! I was quite shocked, just a little "heat-haze" effect but still. Works out at x333. I'm too inexperienced to know if that's exceptional or not but I was blown away, watching the moon slide by between nudges. Unfortunately, it wasn't long before the cloud rolled in and I packed up. Just in time, since there was a short shower just afterwards. Bonus for the night: star-test on polaris looked spot-on.

By all accounts it's one to last you a lifetime, unless you fall out with the whole zoom idea.

No-one's mentioned a zoom yet. The Hyperflex zoom would go nicely with that scope, with x35-x104 magnification. OP should be made aware that zooms have a narrower FOV at the longer end though, which is a compromise typical of most/all zooms. I have the similar 150PL (1200mm F/L) and find one useful. Saying that, last time out I only used a 20mm, 16mm and x2 focal extender and was very happy with their performance. Fixed BSTs or a zoom, either route would be an improvement.

You may have mis-read the OP, I think it's typed as 750mm f/l (F/L) = focal length. Not f/1.0.

The part marked "B" in Pixies' post above might be due to an incorrectly positioned secondary, worth a check. My 150PL recently suffered a bump (carelessness on my part) and I noticed a similar thing on a star-test, not quite as obvious as the OP though. On investigating, I found the secondary had been bumped loose and it had "flopped" so as not to show the whole primary from a collimation cap. Easily solved, although re-aligning the secondary wasn't my idea of fun.

If a moon's orbit is not in the plane of the planet's ecliptic AND there's just the right orbital resonance, it's possible for the moon's shadow always to pass above or below the planet. Likewise, if a moon orbits far enough out, its shadow falls short so there's an annular eclipse. Our own moon is not in resonance but it's far enough from the ecliptic for solar eclipses to be (relatively) rare. Simplify your thinking, pretend all orbits are circular and imagine a moon whizzing around so it blurs and looks like a hula-hoop. Now try and find a place to fit the hula-hoop so it never casts a shadow from the sun as the planet moves through an entire orbit. Don't forget the hula-hoop's Centre MUST be located at the planet's centre. Can't be done unless the moon always passes from above to below the ecliptic and vice versa when it's in the planet's shadow, which means the right resonance between the orbits. Note that I've only thought the above through, logically I hope, in my head...so I may have made errors!

Not on a reflector with no diagonal. If I'm using a Barlow I could put half on that and the other half on the eyepiece for a handy adjustment. Can't be avoided with just an EP though.

If the moon orbits quickly compared to the planet's orbit around the sun, all orbits integrate to a spheroid over time so a shadow can't be avoided. I think to make it possible would require a polar moon orbit and resonance to make the moon pass over a pole when the orbit is side-on to the sun's. Not impossible but improbable. I think...but I could be wrong!

As per above, they seem hard to avoid. I've seen them more times than not and also had them streak across the eyepiece view. Somewhat distracting for visual but a pain in the metaphorical neck for imagers I'd guess.

No point in saying that SVbony is equal to premium brands but if you're on a budget they'll do you fine. I have a 7-21 zoom and a UHC filter and they do the job well enough. I don't have anything premium to compare but I have a Hyperflex zoom that costs nearly double the SVbony and you'd have to look hard to tell much difference. Hope that helps. Rather than a ND filter, I'd suggest a variable-polariser is more useful for very little difference in cost. It's better with a zoom because as you zoom, the brightness will change. Yes you do have to re-adjust by taking the EP out though. I haven't felt the need for coloured filters...yet.

Great experience for you, I bet we've all done it. I certainly have! Go out with the intention of finding something specific, get sidetracked and end up mesmerised by the distraction that you didn't plan on. It'll all still be there next time though. I'm also quite new so most things are still "firsts for me.

The thing to remember with a zoom is that their FOV gets smaller as you zoom out (longer FL). Given that a 3x Barlow takes you into the realms of unusable magnification (maybe with rare exceptional nights), you'd get a slight advantage in FOV by using a 2x and just accepting the "wasted" overlap range. The other thing with a zoom is that you'll probably want to supplement it with a fixed low-power eyepiece for better FOV at that end. Just food for thought...

I've just received a s/h UWA 16mm/82-degree EP, courtesy of Commanderfish/classifieds on here. That's my clear skies done for, no doubt...

I've only been observing (more than just casually, anyway) for a few months so I don't have a reference point. However, it seems that I have seen at least one satellite every time. More often several and not infrequently whizzing across the eyepiece view, regardless of where I'm looking. It's not spoiling my interest (yet) as an observer-only person but it does make me wonder. It feels sad that we aren't content with polluting the ground and oceans. If we aren't careful, we'll also have cut off the possibility of future exploration shots too. I wouldn't want the job of planning a route through!

Back in the news, fragments have been found: https://www.bbc.co.uk/news/science-environment-56326246

I've just replaced my tablet for a newer version since it was on 4.2.2 and could not be updated. I don't use it for astro stuff but there's quite a few apps that won't run the current version on the old one. As said, Android 4 is about 7 years old. Might be worth seeing if yours can be updated but don't hold your breath. It's probably not going to cope, hardware-wise anyway.