Those finders sound heavy. I usually just use a reflex, or sometimes a straight-through on my 127mm Mak and 150mm Newtonian. The zenith, or near it, can be a bit of a challenge though. Two inch widefield low power eyepieces can be a solution, or possibly a zoom.



This is the ST102 with both finders and the Baader Hyperion zoom. The AZ5 seems to handle it all and I'm getting some dexterity back into my right arm and hand, so when the sky soup finally clears I may get to use it on the zenith.



I may have to wait about a fortnight, but the BBC Weather app said it's definitely going to get better. I don't believe them ...

Happy Beltane!

 

HALF A KILO?

 

Jeez Louise, these are 955 grammes. 169 quid sounds reasonable though compared to most Orion RACI's lol.



https://www.altairastro.com/altair-...mage-prism-variable-illuminator-eyepiece.html

 

I ordered both rings (ED72 & ED80) from FLO on 1st of April but the ED80 ring hasn't arrived yet. FLO reckon I should be getting it soon though. Apparently they're more or less made to order in the UK.

 

The Synta ED80, f7.5 is an achromat (doublet), but it has ED glass. I nearly bought an ES 102mm triplet but the OTA with tube rings weighed over 5 kg. And that's without diagonal, EP and finder. So I went with the Altair ED doublet which was a kilo lighter.

For visual an ED doublet is probably as good as a triplet, I think it's only with AP that any real differences show. I use an SXG tripod with my Porta II. It will hold 5 kg pretty easily.

https://www.firstlightoptics.com/vixen-mounts/vixen-sxg-hal-130-tripod-sx-gp.html

 

I can believe the ED80 can reach 200x. I could often get that on my old ST80, although conditions will dictate magnification usually. I've been looking at my notes for this time last year. I was using the ST80 often for Venus and Jupiter but the humidity was hindering any magnifications above about 100 - 130x on Jupiter.

We had a very cold prolonged winter last year which was often referred to as The Beast from the East as it was mainly blown from the Ural mountains. It's not uncommon where I live to get cold winter blasts from the Russian Steppes as I'm at a very high altitude above mean sea level. I live in the country but there is a town about a kilometre to the north east of me which can produce some LP especially when the transparency is poor due to heavy humidity.



I got turned on to the Synta ED doublets after buying the ED72. Synta are a bit coy about what the doublet actually consists of. The crown is Schott but no one really knows what the flint (Abbe number of 50 to 55 or less) consists of. On the ED80 it is Schott/FPL53 Ohara which also seems to be what is utilised on most of the other Synta-made scopes (Sky-Watcher, Orion et al). My guess is that the flint is some indigenous high refractive index glass, probably manufactured in Taiwan or China. Like I said earlier, FPL53 Ohara has more or less become a marketing term now, and is synonymous with high quality. Either way, the ED72 is every bit as good as the ED80 optically.



The 72ED is a nice scope for rich field but with a focal length of only 420mm is a bit short for any lunar/planetary observing. I can't really point the ED80 at the zenith without adding the pillar to the AZ5. It's not a difficult job to set it up but it does complicate things for me. It is a good all rounder though.



I just wish the bloody carrying case was a bit lighter lol.


https://www.oharacorp.com/index.html

 

Yeah, the case is Jason Statham hard but I'm physically disabled and it can get heavy. I like a challenge though lol.



So far, this year, these two scopes (ED72 and ST102) have been the most used. Basically as they are the easiest to take out and set up. The ST102 is difficult to beat for rich field although it's not ED.



In a couple of weeks I'll set the EQ5 up and cover it with a tarpaulin as usual. Once the EQ5 is set-up it's easy enough to take the 150mm OTA out to it. I've only had the ED80 out once this year. I'm still waiting for the visual back compression ring.

 

The ED80 compression ring was finally delivered!


It has a slightly lower profile so may give slightly more in-focus.



Seems to work well.



It certainly makes it easier to rotate the diagonal.

 

And fits in the case better with the Baader adapter!

 

Yes, it's just a compression ring, I have to slacken the screws slightly to rotate. I'm partially paralysed in my right arm and hand so I have limited dexterity. Most of my diagonals have slight nose tapers and won't just pull out when the compression ring is slackened slightly. It does enable me to rotate the diagonal enough for a comfortable viewing position. The ring makes it smoother when it is being rotated and holds it more securely.

 

I have a Baader T-thread helical focuser I usually use on my 150mm Newtonian as it has a single speed Crayford.



Although it does alter the focal plane slightly. Talking of Crayfords, as far as I know John Wall never patented the design.

https://en.wikipedia.org/wiki/John_Wall_(inventor)

Both of my Evostars (ED72 & ED80) have stock two speed Crayford focusers. They're pretty good which is why I'm reluctant to replace them with rotating focusers like my other refractors.



I have some diagonals with helical focusers.