John

My Vixen ED102SS is F/6.5 and gave a 4.1 degree true field at 16.7x with the Aero ED 40mm. The exit pupil is 6.15mm with that combo. Mostly I use the 31mm Nagler though so that reduces the true field to 3.83 degrees at 21.4x but with a 4.77mm exit pupil. An ST120 could produce a 4 degree true field with a 40mm Aero ED but the exit pupil would be 8mm.

Like the old "dap bag" we used to have at school ?

Very nice ! Have you found field curvature an issue with your XW's above 10mm in focal length ? I went for Delos eyepieces at 14mm and 17.3mm rather than XW's because of the reported FC in the longer XW's but maybe it's not such an issue in the real world ?

Yes indeed it is

I think they were sold branded by Meade and Astro-Tech as well a while back. Here is a review of the Astro-Tech version compared with an Orion (Skywatcher) ED120: https://astromart.com/reviews-and-articles/reviews/telescopes/refractors/show/orion-120ed-vs-astro-tech-127edt

So did I. Nice to actually get to see and use one at last ! The JMI 40 inch looks interesting as well

It's on a split ring equatorial. The scope is a JMI NGT 18 dating from the 1990's.

I guess you can fit more Pentax XW's in an eyepiece case if you put them "head to toe". I'm not overly OCD but somehow that doesn't seem right

I'm hoping that being able to use my astro society 18 inch newtonian from time to time will fulfil my aperture ambitions The scope is located just a few miles from where I live so easy to get to. I must say that when I'm using it I realise that my 12 inch really is the maximum that is workable at home ! I must try and find the light shroud for the 18 inch - it's around somewhere I'm told.

Although I do not own a Heritage 130 dobsonian myself, I see regular posts on this forum from folks who I know are very experienced who do use these scopes and think very highly of them. Neil English is the author of several books on astronomy and astronomical instruments and writes reviews for "Astronomy Now" magazine. Here is a link to his experiences with the Heritage 130: https://neilenglish.net/a-newtonian-travel-scope/

Agreed - highly impractical. Imagine where that eyepiece would be observing Jupiter and Saturn from the UK ? - "ladder time" In my case I would also need to explain to my neighbour why half the length my scope was hanging over his garden

Tim Wetherell's masterpiece is one of my all time favourite scopes ! This is even more impractical and unlikely for me but I still admire it - one of John Pon's achromats, this one is a Zeiss 10 inch F/15:

You are really going to need a finder scope (viewfinder I think you call it). Pointing the scope with any accuracy without one is very difficult indeed because the main telescope will show only a tiny patch of sky.

Ah, yes - I've remembered now, you have a Heritage 150 ?

They can be cheaper than light polluted skies as well

You can put filters on the end of diagonal and eyepiece adapter barrels rather than on the end of an eyepiece barrel. If putting one on an eyepiece adapter, check that your eyepiece barrels will not contact the filter before using that approach.

Similar here - bit depressing isn't it ?

I quickly moved to a RACI on my Takahashi as well. The Tak finder was a gem but the lowly Skywatcher RACI is more comfortable to use for me and does the job. All the optical finders on my other scopes are RACI as well so I've got used to that orientation for finding generally. As well as the comfort issue it seemed to make sense to me to have finder consistency across my scopes. Maybe a 3rd party company could come up with a quality RACI conversion for the Tak finders if Tak don't want to go there ?

I think your scope has a focal length of 1000mm so the 6mm will give you a useful 167x magnification. The 2x barlow with the 10mm eyepiece will give you 200x which will probably be the maximum useful most of the time. With the 20mm eyepiece the 3x barlow will give 150x which will be useful as well but it's quite close to the 6mm eyepiece on it's own. Using the 3x barlow with the 10mm or 6mm eyepieces will deliver more magnification than is effective I think. A 32mm eyepiece would be useful to give a lower magnification and show more sky - useful for deep sky object observing. You have a nice neighbour

Clouded out again tonight and it looks to stay that way for the next week as far as I can see. What we call a "lean patch" I guess

It's odd in some ways that I have ended up with Takahashi and LZOS refractors really. The name that I followed with most interest over the years has been Astro Physics. They don't come up for sale often though and to buy a new one seems to involve a waiting list of a number of years. I nearly bought an Astro Physics Star 120ED back in 2013. I made some enquiries elsewhere and the impression that I got (including from people who owned both scopes) was that there was unlikely to be a significant difference between the AP 120ED and the Skywatcher ED120 that I already had. Small differences, yes, but the AP was 3x as much as I had paid for the ED120 so I didn't go for the AP in the end. Maybe a good decision or maybe not When the TMB/LZOS 130 came up for sale I made some more enquiries and the balance of opinion was that the scope would likely be in the same league as an AP 130 or a Takahashi TOA 130 (not identical but comparable) which helped swing the decision for me. I suppose there are a few lucky people around the world who have the opportunity to own and compare a number of the scopes at this level, but not many. Thomas Back's involvement in the design of the objective before his premature death was of interest to me as well. Thomas was clearly heavily influenced by the work of Roland Christian at Astro Physics writing this history of their objectives: http://www.csun.edu/~rprovin/tmb/tmb1.html With the Takahashi FC100-DL, I was looking for a Vixen FL102 as I said earlier but there was quite a lot of excitement around when Takahashi launched a limited run of F/9 100mm fluorite doublet refractors and I did already have a nice little Vixen ED102SS F/6.5. I thought that I had missed the boat with the FC100-DL's but heard that there might be one still available from a reputable vendor (Ian King) so I decided to see if it was still available. It was There have been one or two Astro Physics 130mm refractors on the market since I made my decisions but the asking prices have been more than I paid for both the Takahashi and the TMB/LZOS so I'm reasonably content with my lot now. If I get a chance to use an Astro Physics telescope sometime I'll certainly take it though. The name still has an allure about it Note: I do own one item of Astro Physics equipment - one of their Maxbright 2 inch diagonals which I use with the TMB/LZOS 130 refractor.

Thanks ! Thus far the disk of the planet has seemed fairly uniform in tone. I'll keep looking for tonal variations though

Try to avoid looking through one - the views I had with a 20 inch dob under dark skies at the SGL star party a few years back are still vivid in my mind

Yes, Optical Vision Ltd (OVL): http://www.opticalvision.co.uk/ They do not sell directly to the public though, only through vendor's such as First Light Optics.

It would be really interesting if somebody could do an in depth back to back comparison of one of these newer ED doublets and the Skywatcher Pro equivalent Skywatcher do appear to have rested on their laurels over the past few years. I think the Starfield 102 ED is currently exactly the same price as the Skywatcher Evostar ED100 Pro. The Starfield certainly does look a more attractive package.