PeterW

As noted you can we many stars in a finder scope. If you’ve got a friend, then I’d use binoculars and a laser. A decent pair of binoculars will let you find your object location quite well, unless you’re moving to the most directly light polluted part of London. Then you point the green laser at the object location (being careful as always), your friend then sweeps the scope to align to the beam. Another option would be to find the location with binoculars and then punting the laser down the eyepiece of the normal Finder and put the beam on the memorised object location. Of course I’ve also use Mr Spocks jumping, but sometimes there aren’t enough stars or it’s a long hopping exercise. Which bit of London are you joining? Peter

Another one to keep an eye on and from a company that we know has a track record in astro hardware, cameras and software, unlike some other options. As with the other options, this will succeed or fail on the software and how easy it is to achieve good results. These could be very useful for outreach. Peter

Convergence for closer objects. For really close views you need the “reverse porro” designs like the Pentax papillon so the lenses are closer and thus the fields can continue to overlap for really close objects. Peter

Christopher Hay has done a lot of testing of these types of filters, not always from good locations as you will have read. I caught a glimpse of the California neb from my streetlight infested SQM 19skies. I did have very good stray light blocking around the eyepieces so I could well dark adapt (these filters let little light through, you’ll be looking at a reflection of your eyes if there is any straylight about) and some long dew shields to cut out the local light pollution. Not got them under better skies yet. h-beta are your best bet for galactic nebulae and give them the largest exit pupil (brightest view) you can, two eyes giving a calmer view than one. For reflection nebulae you want a blue CCD filter, ie one that fully transmits upto a given cutoff wavelength, not an older written type that has a Much less distinct transmission spectrum. Peter

Twilight would be mesopic, when you’re observing faint nebulae it’s scotooic and rods only. They will saturate as the light levels increase. I’d use a hydrogen beta filter as most hydrogen nebulae have emission there and the eye is much more sensitive to it. https://www.freunde-der-nacht.net/filterexperimente/h-beta/ (use translation) has a review of different h-beta filters, if you want to go after galactic nebulae. Peter

The Pentax papillon binoculars focus to 50cm and are great for bugs and the like. Hopefully you’ll find a cheaper way to get such close in views. Peter

But I got a few more carefree years for my 12x36II(probably pushing 20yrs old then), then I’ll have to decide if I get a newer model. Interesting to see the 15c and 18x are not going anywhere soon. thanks peter

Had a quick bit of visibility, so I know where to look from a few local areas, will help over the next fortnight. Peter

Anyone got a narrow sodium filter and going to go looking for the sodium tail - 11-16april should be the right part of the orbit for it be visible. Peter

For helping match to what is there at this moment, with correct shadows etc, nasa dial a moon is very helpful. https://svs.gsfc.nasa.gov/5048 Peter

Depends on the glass. Went to Rye Nature Reserve recently, lovely big visitor centre with seats round the edge. Tried using my spotting scope through the window… ugh, not crisp at all, had to go back out into the wind to get the best views. However I’ve enjoyed lunar views with my 12x binoculars whilst lying on the sitting room floor through a window. peter

Ouch, spending too much too quickly. Good to hear that the UK space activity seems to be in much better overall health. Be interesting to see what happens in the coming years Peter

Anyone making large aperture etalons already has the kit and skills for getting the flatness sorted….. Peter

Great to hear you found the jelly, for extra challenge there is more nebulosity “behind it”.. find a deep image, looks like a clawed hand. I’d give Lowers Nebula a look if you’re “in the area”. My toes felt cold just looking at that image… Peter

Happy to ask, not sure what’s currently used, think Dave has retired. They measured some ultra flat ceramic disks I had some years back on a zygo. You can use a liquid surface if it’s big enough. Met a chap from PTB once who had an autocollimator that could measure the earths diameter from the curvature on a cup of water….. Peter

Uses the same LRO data as the 21st century atlas. My only grumble is the contrast/brightness level chosen can make some rima/wrinkle ridges hard to see. Look for rupes/rima Cauchy for example. The hand drawn ones do better here, but fail on the actual, realistic detail. the duplex is a solid, useful atlas to have. Peter

Been active all day, those aurora pulses correspond to the AuroraWatch magnetic spikes. Peter

It’s not bad, my only gripe is the contrast level chosen makes some rimae and wrinkle features very hard to spot. Eg look for rima and rules Cauchy. Whereas the Rukl derived ones are much clearer, but lack detail. Of course changing the contrast scale would make other things less visible. On the whole a very welcome addition! Peter

The 18x50 are a pretty sizeable brick, came across one being used for birding, so don’t know what its night time performance is like. For daytime use I’d prefer a much lighter binocular and a light spotter instead as trying to combine in one ends up with hard to find things and not enough power at the same time. peter

… and trying to find the sun by minimising the shadow area is just frustration! Peter

Or the California that’s nice and high and “quite bright”. Peter

As noted it isn’t a compete loop, the top left bit is missing. There is another big nebulae (angelfish/lambda Orionis) covering most of the lambda Orionis cluster, giving orion “a head”. (M42 is quite titchy). Another one at the edge of the visible realm and demanding great transparency. Peter

Nice one, I made something similar…. In black and it got rather warp and warpy in the sun. Peter

If you want a 10x50 then the APM is a very good option. What you’ll see will depend on skies and the binoculars magnification/aperture. 10x50 is a common size, but others may be better for different things. regardless the more steady you can get the binoculars the better the views. Peter

APM 10x50ED, essentially as good as the mythical Fujinon for a lot less money. Quite weighty, so best used with a monopod to give steady views. Very nice and sharp views across the field. Peter