John

I have a couple of 4 inch, a 4.7 inch and a 5.1 inch refractors. All pretty good performers. The 4's and the 4.7 get used a lot and ride on the same class mount. The 5.1 inch needs a stronger mount and does not get as much use. There are noticeable differences in the performance levels of each aperture although they are not striking I would say. I probably only "need" one of the above but, hey, it's fun to own telescopes - I'm an amateur astronomer 😁 The 125mm ED doublets do seem to offer a lot of refractor aperture for their weight and cost 👍

I have the 3.5, 5 and 7 XW's. Can't fault them. Ethos performance, more eye relief, less AFoV. Much less £'s. That's my summary 🙂

So, as someone who does not wear glasses when observing, I can experience some 85 degree Pentax goodness if and when I feel the urge 😁 Many thanks for the feedback and your thoughts folks 👍 Next decision is whether these will run alongside my Ethos 21mm and 13mm or replace them 🤔 The prospect of an all Pentax line-up is quite tempting: 3.5mm - 5mm - 7mm- 10mm - 16.5mm - 23mm - 40mm

Wow !! those 105mm triplets are heavy aren't they ? My TMB/LZOS 130mm F/9.2 triplet weighs just 1.5kg more. My 130 looks like an inflated and extended version of the 105 in @Captain Scarlet's photo above.

FPL-53 is a low dispersion glass. Fluorite is practically a no dispersion glass. That's why the fluorite element does not show when a laser is shone through it 🙂

It could even be the same scope as a number of 125mm F/7.8 doublets around. WO sometimes plays around with the stated spec a tiny bit to seemingly have something unique. Their XWA "101" degree eyepiece was an example - exactly the same eyepiece as the Myriad 100 degree. Given this choice I'd go for the pedigree of the FS128 every time.

Thanks Stu. I have seen those. I probably started one of them. I was looking for an SGL-slant on these eyepieces with this thread 🙂

I had completely forgotten that I started that thread back in March 🙄 I don't wear glasses when observing and find 10mm and upwards of eye relief fine.

I have owned and used the ES 92's so I know what those are like. It is the Pentax XW 16.5mm and 23mm that I am enquiring about.

Very much so. Thanks Gary 🙂

There are lots of other DIY dobsonian telescope plans on the web. Some are so simple even I could make them ! 🙄 My only tip would be to use plywood rather than MDF if possible. Plywood is strong but lighter than MDF.

Now that these ultra-wide Pentax XW models have been around for a while I wonder if anybody has them and if so how they are finding them ? I've managed to find very little feedback on these relatively new Pentax eyepieces. They seemed quite exciting when they were launched.

OO use smaller diameter tubes than Skywatcher and GSO. My OO 12 inch F/5.3 had a secondary of 63mm diameter so 21% of the primary diameter. Quite modest.

I think the minimum that would do the job would be an HEQ5: Sky-Watcher HEQ5 PRO Go-To Astronomy Mount | First Light Optics Alternatively, for visual use only, you could consider building a dobsonian mount for the scope as detailed here: How to build a Dobsonian mount - BBC Sky at Night Magazine

Interesting to hear about that issue and the solution. My TMB/LZOS 130 F/9.2 uses a very similar approach. If the dew shield motion becomes sticky I will now know what to do 🙂

I think @F15Rules / Dave said that he was happy with his current eyepieces. Why try and persuade him otherwise ? Anyway, this thread is about a report on an eyepiece at the other end of the scale - the Svbony 3-8 zoom 🙂

One of the characteristics of the OO newtonians that I've owned (3 of them) is that the focal point was well outside the telescope tube. A basic 50mm extension tube is usually supplied with the scope to enable most eyepieces to reach focus.

Could you tell us a bit about the scope you were using and the eyepiece / magnification you were using ? Some info about your observing location, local time, observing conditions, what you did actually see etc, etc would help as well. There are lots of reasons why you might have been getting sub-par views but more information will help tie down what could be specifically causing your issues.

I do not think there is a definitive way to identify a meteorite at home. It can be no more than "suspected" or "possible" unless and until it is analysed by a laboratory.

I have been remembering to give the eyepiece clamp a little extra tension. I use one of these Baader 1.25 inch - T2 click locks on my Tak 100 which seem to handle any sort of undercut because the grip strips are longitudinal gripping down the length of the eyepiece barrel.

I've just seen this post on CN from someone who has owned the Svbony 3-8 zoom for 6 months. Maybe he has got used to the zoom action or maybe it has eased a little from use ?: https://www.cloudynights.com/topic/864943-svbony-sv215-3-8-zoom-experience-and-thoughts/?p=13100701

Something that owners work out. My experience is that flaws (minor or more significant) in equipment rarely get addressed by manufacturers. Look at the weak primary springs still fitted to GSO made newtonians, for example, which have been known about for over a decade.

1st thing I did with my newly acquired 200P dob was to put a 9x50 RACI finder on it 🙂

I wonder how long it will take for someone to find a mod that will ease the zooming action of the Svbony 3-8mm ? Rather like happened with Tele Vue's "Instajust" system on the Radians and T4 Naglers.

I agree. Without getting it tested in an accredited laboratory you will never truly know if the origins are meteoric. The UK Natural History Museum is a great authority but there are others around the world as well.