John

Similar result here tonight with the ED120 at 225x. Callisto just does not look as close to Ganymede's apparent diameter as it's listed figure suggest that it should No chance to compare the 100mm / 120mm views tonight - too much cloud about !

It's cleared a bit here and the Jovian and Saturnian detail is showing really well with my non-exotic ED120 tonight I'm seeing 7 belts, the two polar zones, GRS in the SEB hollow, suggestions of white patches / ovals in the southern hemisphere of the planet. Brown's, tans, creams and salmon pink. Nice stuff !

Hide the new eyepiece and stick an old one in the focuser - the skies might clear then Dave It's a similar story here if it's any consolation. I still have a scope out there but the chances of seeing anything through it look very slim indeed

We did it as a day trip once - from Looe ! The crossing can be quite "choppy" as I recall

When I've done this before I've got better results - a couple of times 4/4. I was a little disappointed with 2/4 if I'm honest Edit: Of course 3/4 correct is actually 4/4 of course ! (Doh !!! )

Scope size / weight / mobility. If it wasn't an Orion Optics (quite light) I'd have to settle at 10 inches.

We have an 18 inch newtonian at the Bristol AS observatory that is gradually being put back into service. I expect public viewing sessions will re-start again at some point so others will be able to share the views 😀 12 inches is the practical limit for me at home, where I do 99% of my observing.

That was the (slight) drawback where I was in Dartmoor last week. Very dark skies but no mobile signal without climbing a nearby hill (at least there was a pub at the top !) and no WiFi. Somehow we managed though

Ain't that the truth I could probably afford a Lotus Esprit or similar exotic car now but I doubt that I could get in and out of the thing !

Hope you are having some excellent sessions Craig I had similar conditions on a few nights recently on Dartmoor when I had 11x70 binoculars. Truly memorable !!!

I used to have some nice Vixen mounts

I've used the Baader zoom down to F/5.3 and it seemed quite well corrected across it's field of view. Not perfect but given it's versatility, quite usable. You will want a fixed focal length eyepiece for lower power observing though - the field of view of the zoom at 24mm is rather constricted.

Plossls have eye relief that is around 2/3rds of their focal length of the eyepiece.

The Hyperion zoom is a different optical design to the fixed focal length Hyperions. To me, the ones I've had seemed better corrected in the outer part of the field of view than the fixed focal length Hyperions but that might be because the zoom has a narrower field of view than the fixed eyepieces - it varies from 44 degrees at the 24mm focal length to 68 degrees at 8mm. These figures are slightly different from the official specs for the zoom but are the result of independant measurements by owners.

Well said @Stu The scope that has given, and continues to give, me the most from the hobby is my least expensive and probably the most compromised as well !

Could a 130 doublet be colour free at F/8 even if Fluorite is used ?. I'm not sure it could. If some colour is going to be present, is that a risk for Takahashi's reputation ? I recall William Optics getting quite a bit of flack for the 110mm Megrez F/5.9 doublet because it (inevitably for an FPL-51 doublet) showed a bit more CA than people expected.

It might be more accurately placed than the original one was !

Tak have made quite nice newts

The LZOS optical tests are to satisfy APM that the objectives have matched the required spec. Not aimed at the scope buyers particularly as far as I'm aware. How do we know what Tak are planning for the future ?. The FC100-DL came as a surprise to most I seem to recall.

I think you are looking for the next mount that Rowan Astronomy will produce. It's being thought about at Rowan I understand but I suspect we will have quite a wait until it actually appears.

I've owned a couple of those TAL mounts. They are rugged and won't actually break with a 10kg scope on them but observing will not be much fun with a typical 200mm F/6 dob optical tube on it. The TAL-2 mount is a lot more stable for heavier optical tubes - which is why TAL used it with their 6 inch F/8 newtonian.

At F/5 the outer field of view will show a little more distortion. I found the 8mm BST quite acceptable in my F/5.3 12 inch dob for it's price. I don't recommend Hyperions in scopes faster than F/8 - they are nicely made eyepieces and great in slower scopes but don't seem well corrected for the faster focal ratios. The zoom seems better but it's not a wide field eyepiece at the longer focal lengths. Unfortunately the old adage "Sharp across the field in fast scopes : Wide angle of view : Low cost = pick any two" still holds The ES 68's and TV Plossls do pretty well.

A few years ago I had some time at the eyepiece of a 20 inch dob under a reasonably dark sky and the view of the Messier 13 globular cluster and the Messier 51 galaxy (my choices) were jaw dropping At home (where I mostly observe) the practical maximum aperture I've found is 12 inches but that is with an Orion Optics based dob which weighs about the same as the Skywatcher / Meade / GSO 10 inch dobs. I found 10 inches of aperture was where the brighter globular clusters really "came alive" for me Having the scope well collimated and cooled is important as well to ensure that you get the best resolution of stars both at the periphery of the cluster and deep into it's core. A nice observational target when viewing Messier 13 with a decent aperture is to pick up the nearby small galaxy NGC 6207 about 1 degree to the NE of the cluster. Lovely sight in one of those new fangled ~20mm / 100 degree eyepiece thingies

The middle range BST Starguiders (18mm - 8mm) do quite well in faster scopes like your F/5 12 inch dob. The 25mm in that range is not so good. For low power I found the 30mm Vixen NPL did a good job for it's price. F/5 is quite challenging focal ratio for wide field eyepieces so, on a budget, the choice is limited.

The 25mm BST Starguider is not the best of that eyepiece line, especially in faster scopes. It does pretty well at F/8 and slower though. The 18mm, 12mm and 8mm are somewhat better corrected in faster scopes.