John

Yep. I think it's 10mm for the EQ3-2, EQ5, Skytee II and HEQ5 and steps up to 12mm for the EQ6. Edit: actually it is the lower thread that the OP is interested in (that holds the eyepiece tray) and I think that might be 12mm 🤔

We saw something similar from here in the west country on Saturday evening at about that time. I was at an outreach event with Bristol AS. A chain of lights appeared to rise up from the western horizon in a straight line and then winked out one by one as they went into the earths shadow.

This test report on the Baader Continuum filter is interesting. It finds that the filter is much more effective when used with achromats than it is with apochromats: Test Report: Baader Solar Continuum Filter revisited – now with 7,5nm FWHM / Baader Planetarium Blog Posts (baader-planetarium.com)

I think our eyes are most sensitive to green light (wavelength 530-550nm). Optical guru's say that optics for visual use should be tested in that wavelength. I believe the continuum filter transmits 540nm which makes sense. Probably a good filter to use for star testing as well.

Eyepiece preferences seem to be a very personal thing - what one person likes may well not suit another person at all.

Next time you have a look at Messier 33 on a dark night, have a look for a fuzzy spot near a star just outside the visible galactic "halo" of the galaxy. This is NGC 604 an immense star forming region within M33 and, IMHO, the easiest DSO to see that is actually located in another galaxy. I've seen it with 100mm aperture scopes although it's easier with a little more.

At the shorter FL end I've ended up with a progression of 8mm, 7mm, 6mm, 5mm, 4.7mm, 3.5mm in fixed focal lengths plus 4mm-2mm with .5mm stops in the Nagler zoom plus 7mm, 6mm, 5mm and 4mm HD orthos for when I'm in the ortho mood. You are not alone in having a crowded short end in the eyepiece case ! I've very often noticed with Jupiter that a lower magnification teases out the subtle planetary detail better than pressing on more power. Last night with my ED120 (and similarly with my Tak 100) 8mm / 7mm (113x / 129x) did a little better than 150x on the planet despite the image scale being smaller. With Saturn 180x - 225x was very good. On Neptune it was "all hands to the pump" and 257x-300x to show a well defined but tiny pale blue "marble" and even at times glimpses of Triton around 10 arc seconds from the planetary disk. Its so nice to have some good nights to be able to experiment "for real" and see what works best 🙂

What a great report - thanks for sharing your experiences 👍

Nice and clear here and another outreach session at the Bristol AS observatory. 25 visitors were treated to some fine views with scopes from 4 to 12 inches in aperture. My ED120 was doing very nicely on Saturn, Jupiter and Neptune. I think I glimpsed Triton but with folks waiting to have a look, it was not the time for prolonged study. I also showed people epsilon lyrae and the coathanger cluster. I had not observed the latter for sometime and had forgotten that it's quite a large target. I invited observers to view it with the optical finder first so they could see the form of the asterism against the background stars. The magnified view with the scope at 30x came as a bit of a surprise to some I think. Next door to me was a nice Celestron C11 on a Losmandy G11 mount. Very impressive setup and it was interesting to compare the views of the planets and deep sky objects with those of my ED120 😁 One of the views that seemed to impress the visitors a lot was that of the double cluster in Perseus with my ED120 and the 31mm Nagler. Lots of ooohs and aaahs were forthcoming from the observers. Very enjoyable session 👍

If I remember, spikes on grass, hard plastic tips on concrete though I'm not strict about this. I have used vibration suppression pads (Meade ones I think) and they did make a bit of different to vibration dampening times. I have better tripods these days though which seem more impervious to vibrations.

We had a "scope surgery" night at Bristol AS last night. The aim is to help folks thinking of getting a scope to decide what might suit them and also to assist folks who have recently bought scopes to get them set up right and to give some advice on getting the best from them. The skies had cleared by 8:00 pm so we got some scopes out into the car park to look at Jupiter and Saturn. First time observing these for some there, which was exciting 🙂 Our meeting place is in central Bristol and surrounded by bright lights so it was nice to actually be able to see something from that heavily light polluted location. I'm helping at an outreach session at the observatory tonight and the forecast is not bad for that so more to come hopefully 🙂

Nasa probe launches to metal asteroid Psyche - BBC News I'll be interested in the results from this mission. I have a small slice of the Vaca Muerta meteorite in my collection and 16 Psyche is currently thought to be the most likely parent body for of this meteorite type - mesosiderite.

Thanks for the responses folks 🙂 I'm happy with the focuser tilt on my scope so I won't be adjusting it. I find that the stock single speed crayford seems to do it's job quite well, even with monster eyepieces.

Yes, the end of the diagonal barrel is a good place to put the filter. You just need to remember it is there so you take it off when you move to a target that the filter does not help with. I've done that quite a few times 🙄

Yes, that is what I'm thinking. I wish they incorporated it in their refractors.

I notice that the stock simple single speed crayford type focuser on my Skywatcher 200P dobsonian has a push-pull collimation bolt system fitted which allows the tilt of the focuser to be adjusted. Has anyone ever used this facility to adjust the tilt of the focuser ? Personally, I have not found a reason to adjust focuser tilt with this scope. It would be a very useful facility on some of the Skywatcher refractors that I have owned but, sadly, the focusers on those scopes did not have the feature 😒 It seems quite an advanced feature to have on what is otherwise a rather simple and sometimes rather criticised focuser.

I used an AVX to carry a 130mm F/9.2 triplet refractor which weighs 9.4kg in total and it did quite well. A C8 weighs 5.9kg I think and is a lot shorter than my refractor (tube length impacts mount stability quite a lot) so I think an AVX would carry it well for visual observing. I can't comment on imaging because I'm not an imager. The quoted weight capacity limit of a mount is usually excluding counterweights but can also be a little optimistic.

You called it as you saw it with the eyepiece you had. You can't do any more than that 👍

That is good news Michael 👍

NASA unveiled some initial findings about some of the material recovered from Bennu this afternoon: Osiris-Rex: Nasa reveals first look at 'beautiful' asteroid sample - BBC News It's early days but some of their findings on composition seem similar to that of Carbonaceous Chondrite meteorites, notably the recent Winscombe Meteorite. Much more to learn from this material I'm sure 🙂

When observing really faint stuff under dark skies I've found that ANY light source, no matter how faint or what colour it is, impacts how deep I can see. Even an illuminated watch face quite a few metres distant stood out like a sore thumb a few years back during one really dark night at the SGL star party.

I think the main challenge is that the exit pupil (which is what we are trying to image) is often very small (eg: 1-3mm) so the optics of the mobile phone camera have to be positioned and maintained extremely precisely in terms of both centering and distance from the focal plane to get a decent image. And then there is exposure etc, etc to get right. I have managed a few decent images of the Sun, moon and Venus with a mobile at the eyepiece sometimes using a low cost mounting adapter and sometimes not. Lots that did not work out very well though 🙄

I had one of the older "flat top" style Nirvana 4mm's a few years back and it seemed a pretty good high power eyepiece I thought. The current body style is probably better than the flat top one though. Maybe there is some optical quality variation unit to unit with this one ? Way back I had the 16mm UWAN (same as the Nirvana's) and decided to change to a 16mm T5 Nagler (at some cost) but could not really see much performance difference in the F/5.9 and F/6.5 scopes that I had back then. I recall thinking that the additional £'s might have been better spent back then. I was loaned a 28mm Nirvana (again flat top type) by FLO to compare with the Pentax XW 30mm and Nagler 31mm many years back. I think that was the first eyepiece comparison that I ever did for SGL, 14 years ago 😲: That's all the Nirvana / UWAN experiences that I have to offer.

For me it would be the 80ED because it is more versatile. The 90mm mak is very compact though so if space is at a premium that will be a benefit.

I think one of the challenges with lower power 2 inch eyepieces in a fast newtonian is maintaining the exit pupil at an effective size while maximising the true field width. Sticking with ~70 degree AFoV's adds a constraint but I can understand why some folks prefer that as well as wanting to keep the eyepieces size and weight (and cost) manageable as well. It's a matter of deciding what trade off's you want to make 🙂