John

If you are not keen on a 50 degree AFoV the 4mm TOE will not help much at 52 degrees. I owned one for a while and found it very good but not exceptional. Others will differ from my findings though - that's the way of things 🙂

We all do this stuff from time to time ! A couple of nights back I had the Tak 100 setup and after a gap in the session I popped back out again to have a look at M42. I could not get anything in focus which confounded me because I'd been having lovely views of Jupiter an hour before. What I forgot was that I bought the eyepiece in when I came in for a break and forgot to take it back out again. So I was staring into an empty diagonal barrel in the dark wondering why I could only see vague lights where before had been sharp and sparkling stars - dohhhh !!!! 🙄 When I had the Meade Lightbridge 12 inch truss I'm sure I recall leaving the mirror cover in place more than once !

It will earn it's keep I'm sure. I found it excellent when I tried one and compared it with the Baader Genuine Ortho 6mm.

I have the Nagler 31 and the Ethos 21 and they are both heavy beasts. As well as the weight, I'm motivated by curiosity - I've read a lot about the 30mm UFF variants over the past couple of years.

I find my 2-4mm nagler zoom works fine for me with my un-driven alt-azimuth mounts but it's not an approach that everybody would enjoy, I appreciate. On the eyepiece choice, I'd go for a 4mm as well. I find 225x and more very often in use with my refractors. I tend to prefer 1mm or less increments in the short focal lengths to increase the choices at high powers.

That is interesting to hear Steve. I've been considering those two recently. I'm swayed towards the 30mm UFF now despite my admiration for the build and optical quality of Pentax XW's generally. Hmmm ....... 🤔

This is more limited that I think you are looking for but I compared the Vixen NPL 30mm with the Baader Classic 32mm plossl a while back: Baader Classic 32mm Plossl meets Vixen 30mm NPL Plossl - Member Equipment Reviews - Stargazers Lounge On a side note, I can hardly believe that nearly 11 years have elapsed since I did that comparison 😬

Not mine of course but currently for sale in Germany and a snip at 295,000 Euros - a 14 inch / 365mm F/12 Lzos triplet. Interesting that the objective bears Thomas M Back's initials and seems to date from 2002 according to the test report.

When I want to use a 2 inch diagonal in my Tak FC100-DL I use an Astro Physics Maxbright, which is really a superb item 🙂 Most of the time I use a Baader T2 Zeiss prism though and stick to 1.25 inch format eyepieces.

With smaller to medium apertures I reckon the challenge will be to see some signs of a deformity to the primary star airy disk at approximately the correct position angle. Rather like I managed to get with Dubhe a couple of years back. No split, just vague indications of a "bump" at one point in the primary star airy disk.

I wonder if this 3-8mm zoom will come out under other brandings ? The UFF eyepieces seem to be available under a plethora of brands now and at a range of prices too.

This well known and detailed comparison of diagonals places the Takahashi 2 inch mirror more or less on par with the 1.25 inch Tele Vue Everbright so probably little or nothing to gain except for the facility to accept 2 inch eyepieces should to wish to do so at some point: Mirror vs. Dielectric vs. Prism Diagonal Comparison - Articles - Articles - Articles - Cloudy Nights

Sadly very true IMHO and not just in astronomy 😔

With a limit of £150 the Svbony 3-8 zoom is all I can currently offer up for this thread I'm afraid 🙄 If I was allowed used prices (all of my eyepieces but 2 were purchased used) then a couple more might just squeeze in. I recently parted with a set of 4 Astro Hutech HD orthos (4mm, 5mm, 6mm and 7mm) which I think retail at around £89 apiece, considerably less 2nd hand though. They were excellent performers within the usual abbe ortho constraints of a 40 degree AFoV, small eye lenses and eye relief around 80% of the focal length. The Svbony zoom seemed to match their performance though while offering more comfort. There are plenty of very good sub-£150 eyepieces about these days though so the thread should have no trouble generating a good list of candidates 🙂 The Baader Classic Ortho 18mm and 10mm are pretty darn good for their cost that's for sure. I don't currently have those though.

Here is a relatively recent thread from the CN forum regarding Newton Rings visible in a Tak FC76DS objective. They look almost identical to yours: Takahashi FC76DS Newton rings - Refractors - Cloudy Nights The 4th post in the thread mentions a discussion on this topic with an optical technician at Takahashi Europe who provided reassurance that they are not in any way untoward.

One of the least effective UHC filters that I tried was the Explore Scientific. I don't know what it's band pass looks like but the Astronomik UHC and even my elderly Meade 4000 Narrowband made a much more obvious difference to the contrast and extent of the nebulae I tried them on. I was slightly surprised by this. Most of the other Explore Scientific stuff that I've used has been pretty decent. And they do supply the filter in a very impressive and somewhat over-large decorated and foam filled box as well as the nice little plastic case. Perhaps they should have spent some of their packaging budget on a more effective filter ?

Sorry to hear that but I've had something similar. In my case I lost my voice for 3 days and I'm still speaking in a whispering croak 🙄 Nice to see some starlight this evening though. Made me feel a bit more human again !

Before the forecast cloud cover obliterates things I had a look at Eta Geminorum (Propus) inspired by @Nik271's report here: https://stargazerslounge.com/topic/418615-eta-geminorum-a-gem-in-gemini/ I was pleased to see the fainter secondary star on the outer edge of the faint diffraction ring around the primary star and the colours matched Nik's description. I found 225x and upwards was required to clearly make out the secondary star to the W of the primary. I'm not sure that I've split this one before - it's probably a new one for me, which is very nice 🙂

I've seen them with some Vixen doublets and a TAL doublet that I had but not in Tak FC100 doublets. I put that down to the air space being a touch wider in the FC100 objective design. I agree that they are not a negative thing to see but just wonder why they are present in just one example of that particular scope 🤔

First stargazing / space tourism for ages here for various reasons. Jupiter looks lovely despite the red spot hiding around it's other side. The 4 Galilean moons are strung out nicely to the west of the planet. Ganymede stands out as the largest of the four at 180x magnification. Rigel split neatly and cleanly. I don't think the clearish skies are going to last though but something is better than nothing 🙂

I think the niggling question is why they are showing. I've never seen newtons rings showing on the objective of a TAK FC100 before, and lets face it, there have been enough pictures of them on the forum over the past 5-6 years or so !

Nice report @Stu 🙂 E & F Trapezium were pretty straightforward with my 12 inch dob under any sort of decent seeing. The Ethos 8mm (198x) seemed to be a "goldilocks" eyepiece for that task with that scope. These two fainter members of the Theta 1 Orionis group present a number of visual challenges I think, not least because they are set against a nebulous background. F of course has the added difficulty caused by the proximity of the brightest star of the "big four" in the group, C. Onwards to G & H now then ? 😁

Many years ago I had a Vixen SP102M (under Bresser branding as it happens) which had the Skysensor 2 GOTO system, AKA, the "pale green brick". I think I only ever tried to use it once as a GOTO system but found it very awkward to set up so ended up using it as an over-sized controller for the motor drives. Hopefully the later versions of the Skysensor were more user-friendly !

They are a compromise but can be picked up for around £50 used here including the tripod, sometimes less. With a bit of modding they can do a decent job with a small, short scope. Not everyone wants to spend £hundreds on a grab and go mount so at least they have an option 🙂

Looks good to me as well. I'll bet that the star test is good as well. I don't see collimation as the possible cause of any CA having seen that. Maybe go back to your theory that the diagonal is the cause ?