John

This website covers the CG-5 so might be of some help: http://www.astronomyboy.com/cg5/

Good job Chris - I enjoyed watching that I think you took just the right approach - describe what you see and the experience rather than worrying about detailed specific technical diagnosis

You could use 80mm F/15 refractors as truss poles for something like that !

I've been looking through some snaps we took on our trip to Florida last February, which seems a long time ago now . I came across the one below that I took at the Kennedy Space Centre in front of the Shuttle Atlantis exhibition hall. My other half is stood at the bottom of the right hand SRB. This is a BIG piece of hardware The exhibition of the Atlantis shuttle inside the huge hall is very impressive as well - it's turned on it's side and is literally hanging right in in front of you. Highly recommended visit for all space nuts

I guess that the objective used in the Altair Starwave Ascent 102ED would be suitable: https://www.altairastro.com/starwave-ascent-102ed-f11-refractor-telescope-geared-focuser-467-p.asp I'm not sure that the objectives are available separately though ? Is the current objective in your Lyra 102 F/11 in good shape ?. Apart from a little less false colour, an ED doublet replacement might not deliver much in the way of improvements. The objectives used in the Lyra F/11 achromats were pretty good I seem to recall.

Thanks Jeremy - I will enjoy reading those over my coffee and Jaffa Cake later today

Fascinating stuff from NASA's APOD: https://apod.nasa.gov/apod/ap050401.html

I've been telling myself that for years 🙄 I've not bought one since December last year, so that's something !

If you could do it, masking the Tak FC 100 down to 80mm would give you an F/9.25 scope to compare with the Scopetech 80's

My (limited) understanding is that the brighter diffraction ring means that more energy is going there rather than into the airy disk which can be because of modest amount of spherical aberration There might be other causes as well though.

I don't recall that and, if so, I broke it very early on in the thread !:

I've only purchased a few used items over the past 12 months so it's not me !

What would be interesting would be to compare the performance of a faster ED doublet with one of these long focus achromats. Something like the Skywatcher ED80 at F/7.5 perhaps ? Obviously the faster scope could show a wider field of view but could it compete on planetary, lunar and double star observing where the long, slow refractor optics should provide an advantage ? I'm sure we all have views on what the outcome might be but it would be interesting to do a methodical comparison

Lovely report Neil Looks like a super place to observe from as well

This is the sketch I made using my ED120 refractor a little while back at 257x. The "Pup" star is on the E side of Sirius A so it trails "behind" Sirius as it drifts across an undriven refractor / mak-cass / SCT field of view:

Now there's a line that would create a lively thread in it's own right

I've owned the 30mm and 40mm. The 30mm edge correction is not that great. I believe that the 35mm is better corrected and the 40mm better again proving sharp across the field even in my F/5.3 12 inch dob. The exit pupil diameter is rather over-large using the 40mm though so the 35mm is probably the best compromise in an F/6 scope.

I have the Ercole and the Skytee II. They will hold heavy scopes but to get steadiness to allow the TOA 130 to really show what it can do at high magnifications I think you need something more substantial, with slow motion controls. I ended up with a T-Rex for my 130mm F/9.2 triplet but they are long out of production now. I think the Rowan AZ100 is the best of those listed so far. There is the TTS Panther of course but the price takes a major leap up again there: https://www.peak2valleyinstruments.co.uk/page_3569452.html

Hi, I don't think there is a better option at that price to be honest with you, even though the ED150 has had a substantial price hike recently. The other option is the APM 152 ED F/8 which is nearly £1K more currently. There are a few members of this forum who own the Skywatcher ED150 and they are very pleased with theirs. This owner is UK based: https://www.cloudynights.com/topic/693379-first-light-with-a-skywatcher-ed150/#entry9965092

What a night ! Well done for keeping focused on astronomy despite all those distractions ! I'm lucky that I do all my observing from my back garden so, apart from the odd bat and hedgehog, it's all quiet out there.

Very interesting Stu - I look forward to more on these scopes in due course Petty much a waste of time trying to observe here this evening. Got a few glimpses of stars in small holes in the otherwise rather thick clouds. Glad you had better luck

Great report The Tele Vue DeLite's seem to have gained a really excellent reputation from the feedback I've read on them, including your own I must get around to trying one someday soon !

Iota Cassiopeia ?

Interesting stuff Stu A brighter 1st diffraction ring is the main difference between my Vixen ED102SS F/6.5 and Tak FC100-DL F/9, interestingly. Don't know if you have a view of Auriga but Theta Aurigae is a nice uneven brightness double. Not all that tight though. Zeta Herculis later on ? The closer pair of Tegmine will be beyond 80mm I think but you might see a "notched pair". Edit: Zeta Herc is a bit unfair on 80mm's really I guess

Clouded out more or less 100% tonight, so no "Pup" star