John

Thanks for that link. Baader do have a wide variety of products, don't they ! I currently use the Baader T2 Zeiss Prism which has a clear aperture of 35mm. One of these: https://www.harrisontelescopes.co.uk/acatalog/baader-t-2-zeiss-prism.html?gclid=EAIaIQobChMIy9HV_5qx7AIVxbHtCh20bwE0EAQYAiABEgKr9fD_BwE I currently have the Baader 1.25" click stop on the eyepiece side and the Baader 1.25" push fit adapter on the scope side. I could put a 2" eyepiece side adapter on the eyepiece side and a 2" push fit barrel on the scope side and it would be OK for 2 inch eyepieces with field stops up to 35mm in diameter. I have been wondering if moving to the "full" 2 inch Zeiss prism diagonal would result in any performance loss and the feedback seems to be that is not likely to be the case. I also tend to think that a 2 inch diagonal would provide a firmer foundation for heavier eyepieces rather than the smaller diagonal plus adapters approach. Thanks for the feedback so far - it's been very useful

Interesting thread I often do just look up and wonder at it all. That's very much part of the enjoyment for me. I also wonder what would have been the impact on scientific thinking if, for example, one of today's amateur scopes, eg: a Skywatcher ED100, was somehow sent back through time so that it was available to Galileo ? How would that have changed thinking at that time and subsequent thinking and the pace of understanding ? I really don't know the answer but it's fun to speculate sometimes

I've never managed to see M33 without an optical aid of some sort. Even at the SGL star parties under darker skies than I have here, I've not managed a naked eye glimpse, as yet. Skies are clouding over now here so I've missed my chance. But there will be others and I do love seeing NGC 604. I think it's the only deep sky object in another galaxy that I've been able to see so far

I'm feeling rather awkward now that a review that I posted because I thought it might help a prospective purchaser has resulted in a rather technical discussion in this thread that FLO started announcing these new scopes. Perhaps a mod might snip out some of this and stick it into the scopes discussion section which might be a more apt place for it ? Apologies to FLO.

I'm very tempted because I'd like to standardise all my scopes to having 2 inch eyepiece capability. Currently the Takahashi FC100-DL is the only one with a 1.25" diagonal (Baader T2 Zeiss Prism) but I don't want to compromise the optical quality in this move. Sounds like I won't have to though

Interesting that the vendor took it up with the manufacturer who produced an explanation. If Larry's assertion was incorrect surely the vendor and the manufacturer would have quickly pointed that out ? Setting that to one side, the review was very positive I thought. Here is another positive one: https://astronomytechnologytoday.com/2020/01/03/gso-eight-cassegrain/ Also these reviews are the GSO branded units. It's quite possible that the specs of the Stellalyra units are a little different.

They have shallow undercuts: https://www.televue.com/engine/TV3b_page.asp?id=62

The scope was in the UK in 2015: The seller does not mention the Quark solar eyepiece which is worth £700 or so on it's own. I think the whole thing is very suspect.

Actually, from that angle, they do look similar

I have one just like that. The 3 grub screws inset into the body press against the laser unit and those are how you collimate the unit. To replace the batteries, you unscrew the silver cap on the end of the laser unit using a thin hex key or similar in the hole drilled through it to give you leverage. Hope that helps.

It's a 14mm Delos with the eye guard section in the upper most position. As a non-glasses wearer, that suits me the best. Huge eye lens with the Delos.

I have seen M33 with a 7x35 binoculars on a really good night here. It does help, as usual, to know where it is and roughly what to look for. That is a challenge for first time searchers of these more subtle deep sky objects - not quite knowing what to expect or look out for. Certainly not what the images look like generally ! I've not yet managed to see M1 with binoculars although I know others have. Quite often through scopes though. M1 (the Crab Nebula) is a lot smaller than M33. Considering it's fame, it's not a striking object in small and medium sized apertures, not even larger ones if the transparency of the sky is mediocre.

Just to be clear, are you looking at eyepieces for your current 5 inch / 127mm mak-cassegrain scope or those for a future 10 inch scope, or eyepieces suitable for both ? What eyepieces do you currently have as a starting point ?

M33 is a low surface brightness galaxy. It is a lot fainter and harder to see than M31. Your scope will be able to see it with a very low power eyepiece if the skies are dark and transparent. M101 is in a similar category to M33 - harder to actually see than you might at first think from the published magnitude figures. It is worth persevering with M33 on a dark night - there is a star forming nebula within the galaxy known as NGC 604 which can also be glimpsed with moderate aperture scopes. To start with you will only see M33 as a vague patch of light between 4 stars - almost a subtle lightening of the background sky. https://skyandtelescope.org/astronomy-blogs/paradoxical-messier-33/

The AP was the joint best performing mirror diagonal in BilP's mega test of diagonals. Why not have lovely build quality and that great name as well ?

I have had a WO and the Revelation / GSO and they were about the same in peformance terms as each other. The Revelation / GSO is lighter as @johninderby says.

I have a couple of the Tele Vue Everbrights which are superbly made things (machined out of a single block of alloy) and even the heavy eyepieces such as the Nagler 31 and Ethos 21 are held very securely in them. My Astro Physics Maxbright is none to shabby either. These gems are rather expensive though and the lower cost diagonals do perform pretty well too

I currently use a Baader T2 Zeiss prism diagonal in 1.25 inch mode with my Takahashi FC100-DL. I'm thinking of moving to one of the Baader 2 inch Zeiss prism diagonals with this scope so that I can use my 2 inch eyepieces such as the Ethos with the Takahashi. Is there any discernible difference in the optical performance of these two prism diagonals ? BillP had the T2 Prism fractionally ahead of the 2 inch in this report: https://www.cloudynights.com/articles/cat/articles/mirror-vs-dielectric-vs-prism-diagonal-comparison-r2877 But I'm interested to see if that is the experience of other observers ? I realise that I could use a 2 inch adapter and 2 inch barrel with the T2 Prism but the aperture is restricted to 34-35mm and I would like to use eyepieces with larger field stops than that if possible. Thanks

I find 6mm an extremely useful focal length but it's probably not as useful in a 127mm mak with a focal length of 1500mm. Mine is a 6mm Ethos.

No problem. The view is the newtonian one so S at the top and W to the left. The Pup star trails Sirius as it drifts across an undriven field of view.

Me too !

I'd be careful about rubbing eyepieces or mirrors with a cloth if they are dewy. Better let them dry naturally or use a hair dryer on them. I found that a light shroud produced a number of benefits: - kept stray light off the secondary and primary mirrors which gave me much better contrast on deep sky object. I have a fair amount of stray light my back garden ! - kept my body heat out of the light path of the scope - kept dust / debris off the primary mirror of the scope It made a lot of difference in the performance of the scope in my circumstances.

You might find that adding a decent 2 inch 30-32mm eyepiece and, say, a 6mm, to the zoom would give you a 3 piece set that would cover most observing situations quite well.

Is this seeing related rather than aperture related ? I'm not a frequent solar observer so I'm interested in the answer to this as well.

This is a sketch I made of Sirius and the Pup star showing how it appeared though the eyepiece. As I said, it's not quite like resolving other double stars: