PeterW

You need to get her a pair of bins, so you don’t have to share, you can also use them to go finding things in the daytime. maybe she could do GCSE Astronomy “a bit early”?! Great read peter

Being able to definitely have a few transparent nights of mag 21.5+ would be good. Starparties add a social element for when the clouds don’t part. It seems a number of areas are working up Dark Sky Status bids, where the area’s lighting has to be full cutoff and sensibly powered, which can only be a good thing, bring the darker skies closer and help to reduce degradation of the skies we have. I’m not going to have mag21 in my back garden, but having better closer would be welcome. peter

I coated glass will reflect according to fresnels law, the incidence angle is likely 45degrees though the back of the wedge will be different so it’s reflection is dumped and doesn’t make the eyepiece. https://en.m.wikipedia.org/wiki/Fresnel_equations you can look up a typical glass refractive index curve (https://en.m.wikipedia.org/wiki/Dispersion_(optics) and plug the numbers in. I’d expect reflection across a very wide band, so it you’re worried about the longer IR being an issue then I’d specifically filter for them. Not many glasses trasmitmtoknfar into the harmful UV, but many will transmit UV-A, so some form of filter to trim this off might keep the cataracts at bay a little longer (assuming you always wear sunglasses). Your eye lens will block beyond 1400nm (or so), so beyond that you don’t need to worry about retina damage (your cornea will be smoking long before then!), https://lasersafety.com/resources/laser-safety-guide/ peter

Get yer self some 8x40, 10x50 bins and a star guide or two and get out there and work out where things are, how to find stuff etc. useful in the daytime too for looking at birds, planes etc etc get along to a club (hopefully soon, though the evenings won’t make observing so easy till late summer) and look thorough different kit and see what things look like through them. Also what types of object you prefer and how easy things are to setup/use etc. You’ll always need some spare £ for filters, extra eyepieces and other bits and bobs you never realised existed. I’d only recommend an eq mount if you wanted to image in which case you’d need a good one. Goto is nice unless it decides not-to-goto in which case it’ll drive you nuts. Also quite often you’ll find all sorts of interesting stuff when you’re hunting for something else.. goto only takes you to what you wanted to look at. Bit like walking across London vs taking the underground. I’d avoid too small an aperture as it will limit what you can see. The old “rule”’of minimum 4”refractor or 6” reflector. I’ve got plenty off the secondhand fine and sold plenty too. good luck Peter

Silicon camera with long pass can work, are liked by solar and planetary images for giving crisper images and less instability, though you take a hit on the resolution. There are some long pass filters for planetary and methane imaging applications out there. Very interesting to see the QHY camera. If you can afford one then you could pay one of the numerous custom filter makers to knock up some narrowband filters for those “new” wavelengths. Glass refractive indices tend to be quite flat beyond the red, but reflective optics would probably be preferred… as long as not dielectric coated (you’d need to watch out for IR blocks and check the performance of any “AR” coatings as they’d likely not be away from the visible. For proper IR (think 10micron thermal) you can see the moon OK, but the lack of sensor resolution, atmospheric moisture and cost of optics makes it less interesting. Peter

I hope the milky way is about, the moon most certainly is not and that you have transparent skies. First enjoy the view and try to work out what you’re looking at (too many stars!) Then maybe take some binoculars and have a look around places that you know…… collect as many memories as you can. Peter

….. only a tiny bit into the infrared….. you can see the moon in thermal infrared but not a lot more…. Crap resolution cameras/lenses. As long as people understand the location, equipment, light pollution etc of an observation then they can make of it what they want/need to. Hearing how things appear in different situations is great. NV is little different from using a huge dobsonian in being “different from what the average amateur” has. I like posts from people “doing things differently”, it’s how we find out new things. Peter

I could say both… I’ve got a thermal scope, so I could see you coming if you wanted to enforce your rules! 😉 Peter

If I ever got to skies like that it’d be a firm 1, with a decent pair of bins for wide angle views. Of course if the milky way was not about then I’d try 2 as those sort of skies are best for the Milky Way. Peter

Good luck, I had friends visit and get a week under Saharan dust and almost no stars. If they turn the lights off every night that’s very good to know. peter

Use 1.25” ones and some foam rings so they fit the binocular eyepieces… I do this with nebula filters just fine. Peter

Huh… why? I’ve never felt the need for one even when using a 16” with a low power view. Bright views give the best contrast. You could easily buy some cheap 1.25” filters and fit them to the eyepieces (use a foam ring to snug them in). peter

In response to Zeiss anti fog use on Baader filters, Baader provided the following… ”No problem. But if it comes to cleaning - less is more. If you scrubb off each dust-grain seperately no coating will withstand in the long run. so it is much preferable to cleane once a year and not to spare on the cleaning fluid then.” Peter

As they result in you needing to wipe your optics more than normal there will be additional risk of scratches, so care is needed. Only needed in those chilly and damp nights. I’ve asked Baader for a comment. peter

Any specific brands or chemicals? peter

I wouldn’t use anything on a first surface coated mirror, but use on a hard multi coated filters I’ve no concerns. Just keep obvious dirt blown off and use lint free tissues to minimise and risk of scratches and you should be fine. peter

Getting to 6-7mm exit pupil needs a reasonably short focal ratio or the eyepiece focal lengths get hard to find. I have made some small foam disks that can hold 1.25” filters into the binocular rubber eyecups with friction, no threads needed. Using anti-fog spray helps avoid frustration on dewy evenings. Peter

You can use filters with binoculars… on the eyepiece end, you do need a widget to hold them on and you do get issues with bandshift as you go out from the centre of the field. You could also consider larger large exit pupil binoculars of fast Newtonian too. Peter

… never mind the rabid wild Haggis….! Peter

Sounds great, but worried about what beasties might eat you if you fell off that little ladder in the dark… your “Michelin man” suit would probably save you! Peter

Don’t envy Magnus too much, he’s usually cocooned under cloud… note the shock of having more than one clear night in a row 😉 ! Peter

Great talk from Owen as always. Peter

Great to hear, I first saw the HH at a starparty with nearly as dark skies in a 20” and it was a faint broad gap in an equally faint broad band of nebulosity. Peter

I guess the only thing to worry about up the hill are yetis?! Maybe I need to find a mask that deals with the frosty breath issue. My bino face shield did quite well earlier in the year. Our luck, we get solid cloud and @Captain Scarlet gets clear skies! Peter

You’d need specialist kit with those narrow bandwidths and very deep blocking values. Top companies provide the spectral data for download in both %transmission and Optical Density units. Chroma do, you could ask the others if they have the data to share. If they stand by their kit then they should be happy to, otherwise we will do comparison and determine the models that heat suit our application. Peter