John

Nice movie and I did see the Apollo 11 eyepiece, briefly. I wonder if the young man is connected with the Tele Vue company in any way ? The reactions were great - thats why I love doing outreach Mind you, they react like that when more ordinary eyepieces being used as well !

The Travelscope 70 is an F/5.8 achromat refractor so it's mainly designed for low to medium power observing. Using short focal length eyepieces will give more magnification but the view is unlikely to be crisp and clear over around 60x-70x and the chromatic aberration that the scope produces (in common with other scopes of similar spec) will become more and more apparent.

The finder on those is a 5x24mm I seem to recall. It's not an achromat lens and it may even be stopped down to a smaller aperture by an aperture ring just behined the finder objective lens. That said it should at least come to some sort of focus. I think the eyepiece end can be screwed in and out to reach focus on those finders ?. Rather like the one I've pictured below.

Mine are 1986. I don't think the design changed much in a couple of decades.

I have a pair of those. Made in USSR (so that dates them) by Komz. Very nice quality binoculars and very close performance to my Zeiss Jenoptem 8x30s. I believe the same factory also uses the BPC and "Baigish" brand names for their products.

Some small fragments of the Allende Meteorite which fell in Mexico in February 1969. It's one of the best studied meteorites in history, perhaps at least in part because it fell just a few months before the Apollo 11 mission lifted off, interest in space exploration was high and many instututions in the USA were geared up to study the rock samples from the Moon. The Allende Meteorite fall gave them some early extra-terrestrial rock to examine ! Allende is classified as a carbonaceous chondrite meteorite and contains calcium-aluminium-rich inclusions or CAIs (the irregular white shapes) which are thought to be some of the structures that formed in the earliest stages of the solar system. They have been dated at 4.568 billion years old. An interesting little addition to my meteorite collection

I thought this eyepiece might have been an "April Fool" excercise when it was 1st publicised back in April but I can see that it is a serious comemorative production piece now. I agree that it would have been nice if it's actual availability could have coincided with the dates of the Apollo 11 mission though. Maybe it marks the start of the ultimate replacement of the long-lived Nagler line of eyepieces ?. Tele Vue say nothing to support this though. I'll take a punt at £450 as the UK retail price, when it actually becomes purchasable.

Yes it was Luton Russ. I never actually visited but I pored for ages over their brochures before making a decision. Those brochures also made me aware of the Vixen flourite refractors - and the fact that they were a long way out of my reach at that time financially

I've not managed to see a saturnian moon transit but I did observe the planet when the rings were edge on to us around 2009-10. I can't recall a point when the rings simply were not visible but I do recall their angle being so narrow that they looked rather like a sharp needle of light sticking out of either side of the planet. I found this EAS article dating from 2009 on such transits: http://www.esa.int/Our_Activities/Space_Science/Four_of_Saturn_s_moons_parade_by_their_parent/(print) My understanding is that the "window" of time when these events can be viewed is short - just a few months and during that time there may only be a handfull of transits visible. Add to that Saturns position which might not be favourable during that time plus variable weather and I suspect actual observations by amateurs are rather rare.

Do you think it was the sling itself or the way that it was implemented that was causing the astig issues Piero ? Either way, I'm glad you have got to the bottom of it.

Those were the days - dodgy adverts in the back of the Exchange & Mart. I think the section was called "Scientific Instruments" ? I've still got a few BC&F catalogues - the earliest with the "models" sporting flares, aran sweaters, lab coats and butterfly collar shirts ! Our equivalent of the "Celestron Girls" I suppose ......

A 400mm focal length scope used with a 24mm eyepiece with a 68 degree apparent field of view will show a true field of 4 degrees.

You will need a combination that delivers a true field of view of 3.5 - 4 degrees. For me this is my Vixen ED 102mm F/6.5 refractor combined with a 31mm Nagler or 40mm Aero ED eyepiece. And a decent UHC or O-III filter helps a lot as well. Scopes that have a focal length of 500mm - 700mm combined with a 2 inch format eyepiece of 30mm focal length or longer will deliver that very large true field. And a 2 inch format filter of course to enhance the contrast of the nebulosity. Another combination that would do it would be an ST80 refractor plus a 1.25" 24mm 68 degree eyepiece (eg: the Explore Scientific 24mm 68). Then you can use a 1.25" filter. Yet another option would be one of the 100mm F/4 newtonians such as the Skywatcher Heritage 100. The eyepiece and filter requirement would be the same as the ST80 refractor. You could substitute the 24mm 68 degree eyepiece with a 32mm plossl which might keep the cost a little lower. I'd probably try and stick with the 24mm / 68 degree eyepiece with the 100mm F/4 newtonian though.

Probably cost Jeremy. I was on a very tight budget back then and I think the Astro Systems OTA cost a bit less than a Fullerscopes. The AS had a David Hinds made primary and performed very well I seem to recall. I ordered the OTA first and had it on a self made dobsonian mount while I saved up for the EQ mount. The EQ's sold by AS back then were Vixen SP's which were great but over budget I'm afraid. I had to really watch the pennies back then with a new mortgage !

Thanks - I enjoyed reading though the BC&F history I was a regular visitor to 63 Farringdon Road from the mid 1980's for around a decade. Whenever I had to be in London for business I managed to find my way there, even if the business meeting was on the other side of town ! I bought a Fullerscopes Mk III mount from Dud himself and had some interesting phone calls with him as I gently chased it's production progress Great memories Here is that mount carrying an Astro Systems 6 inch F/6 newtonian - my first "proper" scope and one that I used to observe Halley's Comet in 1986:

Or this price ?: http://www.opticstar.com/Run/Astronomy/Astro-Accessories-Telescopes-Opticstar.asp?p=0_10_5_1_8_330

I've owned Mk2 and a couple of Mk3's. While they were not perfect eyepieces, they fulfilled the Baader Zoom's reputation as excellent zoom eyepieces. Personally I think the 7.2 - 21.5 that I now have is as good though. Not such a wide field across the focal lengths but optically pretty good.

There could be something in that, I agree. The rear of my primary is very open due to the simple cell design so it cools evenly I guess:

This is a bit confusing though: "Primary mirror diam. (mm): 125" (mm presumably) The ETX 125 used an oversized primary as far as I know - 138mm is the figure that I've seen measured. That would tally with a working aperture of 125mm. Probably just a sloppy spec from TH.

Interesting reading this. Your scope seems quite "particular" Piero. But maybe these are just teething issues ?. When I think about how little care I take over collimation (above a quick tweak at the start of the session) and the rather basic primary cell with my 12" F/5.3, it's slightly embrassing I have a fan behind the primary but I never use it. No sling either - just the older OO 3-point cell. When you say that you are seeing astimatism, do you mean an elongated airy disk / diffraction rings on one side or something else ?

That looks neat John. Is the rear cover plastic or metal ?

I have the feeling that the Lunt zoom is the same eyepiece that have been linked to above under different brandings. I have compared mine to a Lunt zoom and, apart from the branding, it looked and performed the same. Lots of choice in this design, Skywatcher do one as well: https://www.rothervalleyoptics.co.uk/ovl-hyperflex-7e1-72mm-215mm-high-performance-zoom-eyepiece-125.html Look at the price on this one with Orion (USA) branding !: https://www.astroshop.eu/eyepieces/orion-7-2mm-21-5mm-1-25-zoom-eyepiece/p,17113

I have one of these which was a very good H-Alpha scope and pretty good at night as well. It certainly looks the same as the TS one: http://www.opticstar.com/Run/Astronomy/Astro-Accessories-Telescopes-Opticstar.asp?p=0_10_5_1_8_330 I think the TS spec for the max field of view is more accurate than the Opticstar one though.

"Astro corner" - I have a couple of those around the house Lovely setup Piero - looks super in that "natural wood" finish

In the words of Hawkwind, "Hurry on sundown, see what tomorrow brings"