John

Very interesting report on the ED150 Mark I reckon it's got more to give under the right conditions.

Got the little blighter ! First time I've managed it with the ED120. Quite hard and I repeated the observation about 10 times with 2 different eyepieces to make sure. The "Pup" star was not consistently visible but was positively there during periods of the steadiest seeing. I was motivated to sketch the view with the 3.5mm Pentax XW eyepiece at 257x (refractor plus mirror diagonal view):

I've just been having a quick amble around the double stars in Orion now that my ED120 refractor has cooled down. The seeing seems to be absolutely top notch here currently Text book high power star images. A real pleasure to observe Rigel, Alnitak, E & F Trapezium, etc, etc. Really clean split of 52 Orionis at 360x !!!! - 2.5mm setting with the 2mm-4mm Nagler zoom. Steady as well - wafer thin dark thread between the airy disks. Dawes limit for the scope is .97 arc second and I believe 52 Orionis is around 1 arc second in separation so no complaints at all here

A 4 inch refractor of this quality for under £500 is an outstanding buy IMHO. And thanks to your review, we know that it is a good one too It does beg the question of what we actually get when we pay 4x-5x more for a similar spec scope from a premium brand with a different type of glass in it I suspect "not a lot" is the answer for many ! Thanks for compiling and posting your thoughts on this scope. Having done similar stuff in the past, mostly on eyepieces, I fully appreciate that it takes time and thought to do this and it can also be quite a nerve racking process "sticking your head above the parapet", so to speak

Great stuff Paul - very useful info and images as well I'll be out again later, with the ED120 this time.

Lovely Stu ! "OK-4 fest" does not sound as enticing as a "Fluorite Fest"

Hi, Good stuff so far ! How much have you used the scope and mount so far ? A few sessions with it will start to inform your choices as to what might benefit your visual observing. How much astro budget do you have left for further purchases ?

Amazing setup Simon

Excellent - I have one of those and that performed very well on the Moon last night

Excellent stuff ! I agree with Jeremy, you will get good value from shorter focal length eyepieces. I find a 2mm-4mm zoom often in use with my FC100-DL. 300x was wonderful last night on Iota Leonis

So far this year I've not seen it with my Tak 100mm or ED120mm. I've needed my 130mm refractor or 12 inch dob to do the job. I'm sure the smaller apertures can do it but the challenge is just made that much more difficult because the airy disk and surrounding glare from Sirius A is a little larger and the glimmer from Sirus B a little fainter. I'll try the ED120 tonight I think - working my way down the apertures !

At the current time, the Pup star follows behind Sirius A as it drifts across an undriven field of view. It does appear as a faint glimmering point of light which comes and goes with as the seeing varies. The seeing and reducing light scatter around Sirius A are very important to spotting the Pup star.

Do you mean the Stellarvue Optimus 100 ? https://www.stellarvue.com/100-110-degree-optimus-eyepieces/ If so, they are the same basically as the APM XWA's I believe.

I can vividly recall the Viking missions, reading the reports and being amazed at the images as they were published in the papers. I was 16 years old so it was an influential time for me. A couple of years ago I had a chance to acquire the original painting below by David C Early F.R.A.S. It was painted in 1977 and is based on the Viking 1 and 2 images. It is quite a large work (100cm x 75cm) and occupies a wall in the "astronomy end" of our dining room 😀

Actually I've been tempted out with the Tak 100 by a dodgy man from Oakworth

Thanks for the "heads up" (again !) on the Mare Orientale Paul 😀 I was not going to observe tonight but your post prompted me to get the Tak 100 out and onto the moon. I'm not sure if I have observed the Mare Orientale before but I have now ! The scale of the thing is quite apparent from the concentric mountain ranges Cordillera and Outer and Inner Rooks. Lacus Autumni is showing nicely and other darker patches - part of the Lacus Veris perhaps ? I've found this guide on the CN forum useful: https://www.cloudynights.com/topic/674322-mare-orientale-a-glimpse-of-the-far-western-limb-of-the-moon/ Also the SW Limb charts L5 and L6 in the "21st Century Atlas of the Moon". Thanks again Paul !

Yours looks lovely as well Dave 😀 I did check out E & F Trap and Alnitak last night and quite a few others too plus some lovely lunar views. The seeing was pretty good. Having a night in tonight. More clear skies forecast over the next few days though.

There have been quite a few over the past few years that have been visible in amateur scopes. I've observed about 10 I think. Here is the current list of the brightest: http://www.rochesterastronomy.org/snimages/ Nothing above magnitude 14 just now. I think the one in M82 in early 2014 was the brightest that I've seen - magnitude 10.5 at it's peak. The last one in our galaxy was over 400 years ago. Perhaps we are due another ?

I don't filter or stop the scope down to observe the moon, even with my 12 inch dobsonian. I do tend to use high magnifications though. I carry a moon filter with me for outreach sessions though, in case anyone feels uncomfortable observing the moon without one.

If you reduce the aperture of the scope by using the small opening in the end cap, your "new" aperture is that of the hole so around 52mm if I recall correctly. So then you will have the resolution and light grasp of a 52mm scope, ie: significantly less than that of a 200mm scope.

I think the mounting holes are in different places Baz (that one is for Skywatcher type finder bases) so you need something like this: https://www.firstlightoptics.com/finders/baader-universal-quick-release-finder-shoe-base.html The elongated mounting slots give you the flexibility to match the mounting holes in the scope tube. There are less expensive ones around than the Baader if you search around.

Any of them could get the Pup but I would think that the 150PL, in good collimation, might be the best bet. My 130mm refractor showed it quite well tonight at 200x and above.

I had a look at 4 Vesta tonight with my 130mm refractor. At magnitude 5.9 it is easily visible in my 9x50 finder and currently forms a convenient pattern with stars between Chertan and Denobola in Leo: It showed as a pale golden spot of light in the scope eyepiece. It's apparent diameter is around half an arc second so no point in trying to see it's disk !. After observing 4 Vesta, while warming up inside, I was prompted to have a look at 3 small specimens from my meteorite collection. These are samples of meteorites from the H.E.D. group, Howardite-Eucrite-Diogenite, achondrite meteorites formed by igneous processes on a differentiated parent world. Current research points to a strong possibility that the asteroid 4 Vesta was the parent world for these space rocks which eventually fell to Earth after millions of years in space. Here are my little pieces of this interesting material:

Some wonderful lunar views tonight with my 130mm refractor Rich detail of the terrain visible along the terminator of the 97.7% illuminated disk. The Rimae Sirsalis was easy to pick out running for over 400km across and between craters, mountains and plains. A little more challenging was the Rimae Darwin which bisects the crater of that name near the prominent, smooth floored Crüger and eventually appears to join with the Rimae Sirsalis, at right angles to it. The floor and walls of Darwin Crater might be best described as chaotic with a wide mixture of terrain visible besides the Rimae. Crüger on the other hand has a really rather smooth and noticeably darker floor and well preserved ramparts. I can't recall observing this particular crater and rille before. The conditions allowed 300x - 400x to be used rather effectively. Apparently the Rimae Sirsalis is not only the longest rille on the Moon but also the site of the strongest magnetic anomaly. Here is a link to a very nice photo of this area by Brian Donovan: http://www.donovanimages.co.nz/media/astrophotography/lunar-craters/Darwin-Cruger-de_Vico.html And a link to a nice piece on the "Cloudynights" forum by Tom Glenn on observing this part of the Moon: https://www.cloudynights.com/topic/640281-observing-guide-to-rimae-sirsalis-the-longest-rille-on-the-moon/

A little milky here but otherwise quite good. Steady for doubles. Sirius B fairly easy to see at 200x +