John

Roger Vine posted some similar tests a while back on his "Scopeviews" website: http://www.scopeviews.co.uk/CARank.htm

I guess the risk is that you might not like the 100 degree eyepiece experience ? Personally I enjoy them a lot but I know they are not everyone's "cup of tea". The Baader Morpheus seems to be popular with everybody who uses them. In terms of overall performance the two will be pretty much the same I reckon. The 13mm XWA will be a big chunk to have hanging out of a barlow or focal extender of course although the Morpheus is also quite sizeable.

We spent a few (rainy) days staying with my brother and his family over Christmas and he introduced me to the joys of 3D printing. We managed to produce this 150mm long replica of the asteroid 433 Eros. We used public domain images to produce the necessary file for the 3D printer. Quite pleased with the result although it took 8 hours to print ! Just got to decide on a few other suitable subjects now (suggestions welcome ! ). 433 Eros was the object that the NEAR Shoemaker probe made the (very) close approach to back in 2000. The first image is from that probe. The others are of our replica. The real thing is 34km long by 11km wide.

Personally, if the CA control is what I would expect from the aperture / glass type / focal ratio then it's the star test quality (extra, intra and at focus) that really sells a scope to me and what I think will give a scope the edge in performance, particularly at high magnifications. It says more about the optical quality (ie: figure and polish) of the objective than the colour correction does I feel, although we would like that to be good too of course

Very interesting results Mark I guess with aperture being part of the CA equation, the 60mm F/6 using an FPL-53 element was always going to be in with a good chance. Likewise at 120mm and F/7.5 it takes a triplet, also involving an FPL-53 element to completely control visible CA. I'm sure the views are lovely with all of them ! Do the chinese scopes use Japanese glass or do Ohara produce FPL-53 in China now as well as elsewhere ?

The good thing about the F/8 150P dobsonian is that a mirror of that focal ratio has a proportionately larger collimation "sweet spot". I think the figure is 11mm for an F/8 compared to 2.8mm for an F/5.

I used to have a William Optics vixen-type dovetail bar which I thought, for a vixen-type, was very solid indeed and allowed a 4 bolt fitting to the tube rings. https://www.firstlightoptics.com/dovetails-saddles-clamps/william-optics-vixen-compatible-dovetail-plate.html Mine was the long version of the above.

Nice job Steve

I've followed a similar approach to others above - my 100, 102mm and 120mm refractors use Vixen-type dovetail bars but the 130mm F/9.2 gets a Losmandy bar. I did use the bigger scope on a strong version of a Vixen-type bar for a short while but decided to move to the larger one and it just seems more solid. My refractors are all side-mounted on alt-azimuth mounts. I do use better quality dovetail bars though. Those long stock Skywatcher type bars do seem a more prone to flex and vibration.

I was loaned one of the Explore Scientific 1.25 inch 2.x focal extenders a few years ago to compare with the Tele Vue 2.5x Powermate that I had at the time. The ES focal extender compared very well indeed quite honestly. Personally I like the way that these devices (compared to barlow lenses) have much less, or no, impact on the point where eyepieces reach focus (important if your focuser has limited travel), don't tend to vignette the field edges when used with eyepieces with close to the maximum field stop size, and don't extend eye relief. I don't use barlows or extenders much these days but have kept a Baader 2.25x barlow which are basic but quite good optically, for occasional use.

Hello, Just to complete the picture, can you let us know what eyepieces you currently have to use with this scope ? On the performance increases, having often compared the views using both low-mid price and much more expensive accessories I feel the differences are almost always subtle so much more in the 10%-20% area. That's not to say that such improvements are not worth having but I guess I'm trying to be realistic with the gains that can be made. Nice scope to own by the way

I've used the Baader Fluid and their micro fibre cloth for a few years now. It has proved excellent.

This was posted on the RAS website earlier this year but I've just come across it: https://ras.ac.uk/news-and-press/news/can-you-help-us-find-moon-trees They are eager to trace the whereabouts of trees in the UK that were grown on from seeds that flew around the moon during the Apollo 14 mission in 1971. Apparently there are no records of where these trees might have been planted even in the obvious places such as Kew Gardens. This search was prompted by a question on the "Gardeners Question Time" radio programme. Personally, I've no idea but someone out there might be able to shed some light on this ?

The ES Focal Extender will have less, or no, impact on focal position, field of view vignetting and eye relief, which the barlow will impact to some extent. As @JeremyS says though, 2 inch barlows / extenders are bulky things and can create quite a lot of stress on the focuser as well as scope balance.

I've probably posted this earlier in this thread but I was 9 years old when Neil Armstrong walked on the moon and I strongly suspect that the coverage of the Apollo programme ignited my interest in space and astronomy. Actually I suspect it was the reports of the Apollo 8 mission in 1968 that grabbed my imagination first. My secondary school had an astronomy club which I joined at age 11 or 12 and that built on the interest. I borrowed a small scope from a friend around that time and observed Jupiter over a couple of months with it. The Viking missions to Mars in 1976 also made a big impact on the 16 year old me. 53 years later, I'm heavily committed to astronomy as a hobby. It won't go away I'm sure, even if I didn't own a scope

I feel this is one of the biggest challenges for newcomers to the hobby who do not wish to invest in GOTO mounts. Once the obvious and easy to find targets have been observed and the enthusiasm fired, quite naturally folks want to progress onto slightly more challenging targets but can find this daunting and frustrating. I have wondered if we could start a thread or even a sub-section in the observing part of the forum where more experienced observers can post their favorite "star hops" or similar target finding advice, charts etc which can gradually build into a readily accessible resource for those building their experience and widening there observing "repertoire" I'd certainly be happy to contribute to that (and borrow some as well !)

Yes, it's a dilemma

That advert reminds me of the bad old days of Tasco advertising ! Sky & Telescope produced this fake advert for an article on avoiding these sorts of scopes a couple of years back. Quite funny except when you find a real one that is still trying it on

I hope that short peek though mine a couple of weeks back has not been a bad influence on you

Not for me, I really think they are worthwhile (well, the UHC and O-III anyway) (apologies if I have misunderstood "Meh" !)

I use UHC and O-III filters with my 4 inch refractors and find them effective on a variety of nebulae. For some targets the O-III filter is the only way to get anything much visible in the eyepiece. Using an effective exit pupil is important to the impact that these filters make. I find that 4mm-6mm exit pupils help an O-III filter the most while with a UHC filter I think you can push that to the 2mm - 5mm range. Not hard and fast rules though. I don't use an LP filter myself but many folks find the Baader Neodymium filter good for this role.

Great stuff Paul ! Compared to how quiet the Sun was last year this is really spectacular

I've just thought of another one: - Make more of this forum in terms of continuing to learn and making useful input to help others I think I can do better at this than I have over the past 6 months or so.

My astronomical aims for 2022 are: - To make much more use of the equipment that I now have: it has all got to start "earning it's keep" I feel, or ...... see last aim ! - To use the facilities at my society observatory more often, especially the 18 inch scope there. - To try and get together with others to observe more often as it hopefully becomes more feasible to do so. - To share the observing experience with as many people as possible who have little or no experience of looking through a telescope. - Depending on how the first of these aims goes, to reduce my equipment level to what really gets regularly used.

Nice report Mark - having been in Lincolnshire for the past 4 days I concur with Dave (above) Glad you got a clear spell and saw Atlas