Lunar Crack with the Big Mak!

[Nightspore]

Frankenprism:

 

 

Assembled from borked originals. Main body is GSO, nosepiece from borked Long Perng and the helical eyepiece holder is from a borked WO Amici.

 

[+Streetbob]

Which amici diagonal would you recommend?

[tuckstar]

12 hours ago, Streetbob said:

Which amici diagonal would you recommend?

I went for the baader zeiss amici. Reasuringly expensive! And I wanted it to be atleast as good quality as the rest of the glass in the train. I went with the 1.25", but it doesn't come with a nose piece or eyepiece holder so factor them in as well.

[+Glafnazur]

My copy of 21st Century Atlas of the Moon arrived today, I've not had chance to have a proper look yet just a quick flick through, but it looks just the ticket, thanks for the recommendation 🙂 

 

 

[+Bino-viewer]

@Streetbob  APM make one as well in 2 inch, but fully equipped.

See below. One or two of EMS use them and they are well thought of.

I have the smaller Baader version as well, the cheaper one, but its set up for binoviewing with a quick changer bino coupler.

 

https://www.apm-telescopes.net/en/apm-2-inch-erect-image-prism-with-fast-lock-and-ultra-broadband-coating

 

Reason why they are expensive, is they are difficult to make well, AND be good enough for critical astro observation.

You only need to take a look inside them !

 

It appears Baader now do a version WITH a 2" holder and nosepiece like the APM equivalent.

Item #2956152

 

https://www.baader-planetarium.com/en/accessories/optical-accessories/prism-and-mirror-star-diagonals/baader-2"-amici-erecting-prism-90°-with-2"-holder-and-2"-sleeve.html?___SID=U

 

HTH, Rob.

[Nightspore]

On 24/04/2022 at 12:33, Bino-viewer said:

 

 

It appears Baader now do a version WITH a 2" holder and nosepiece like the APM equivalent.

Item #2956152

 

https://www.baader-planetarium.com/en/accessories/optical-accessories/prism-and-mirror-star-diagonals/baader-2"-amici-erecting-prism-90°-with-2"-holder-and-2"-sleeve.html?___SID=U

 

HTH, Rob.

 

 

Baader don't actually make these. They are Long Perng.

 

 

Also these are sold under a variety of brand names.

[Nightspore]

On 18/04/2022 at 18:51, Streetbob said:

Which amici diagonal would you recommend?

 

This is an interesting question. I've tried a few over the years. I started off with a resin bodied GSO (below) although I bought it as 'TS Optics'. It has no brand name but is recognisably GSO. I mainly used it on a 102mm Mak for lunar viewing. Sometimes with an ST80. The housing has a metal base and the nosepiece and eyepiece holder are aluminium. There is no compression ring. They're fine for the Moon with no hint of the diffraction spike. Rich field is also OK but there can be spiking on bright stars. Planets can suffer from this, depending on conditions. It's not so apparent in daylight (except with Venus and often Jupiter near opposition). Catadioptrics fare better with spiking than refractors however. I don't know why. 

 

 

I've experimented with other makes. I'm pretty convinced the Orion is Synta, as used in RACI finders.

 

 

The Antares (second from top, below) has a brass nosepiece, I don't know who manufactures it. The WO with the helical focuser has an aluminium body and is probably Kunming United Optics. I honestly can't tell any real difference in visual quality between any of these.  

 

 

The 1.25" 'Omegon' (below, top) has an aluminium body and a compression ring. The eyepiece holder is brazed in place but the nosepiece can be threaded out. All of the threads on the non-Baader Amicis are identical. The nosepieces and holders can be interchanged.

 

 

WO recently changed the design of their helical Amici. I can't see any visual differences between them. Although I personally preferred the older type.

 

 

The predominant difference between these and the Baader 'Zeiss' specification 1.25" Amicis is that they all have only about a 22mm wide clear aperture. The 'Omegon' below is Long Perng.

 

 

The Baader 'Zeis spec' 1.25" are actually BBHS coated and are easily the best of the 1.25" Amicis. 

 

 

There are two 2" Baader Amici versions. The cheaper one is Long Perng.

 

 

The APM Amici is optically a step up from the Long Perng Baader. It features a click lock without a compression ring. 

 

 

The ultimate 2" Amici is almost certainly the Baader BBHS. It isn't cheap though. 

 

 

At the end of the day, the Baader BBHS and APM prisms are made to better tolerances and have bigger clear apertures than the others. The less expensive 1.25" Amicis are more or less all the same. Apart from differences in housings. A simple resin bodied Amici would suffice for much lunar viewing. They're lightweight and relatively inexpensive. The WO's have a helical, which is useful on catadioptrics. The Omegon/Long Perng and WO would probably hold heavier eyepieces more safely as they are all metal.

Edited April 25, 2022 by Nightspore

[+Bino-viewer]

Thanks for the detailed summery.

Theres plenty to choose from there !

[Nightspore]

1 hour ago, Bino-viewer said:

Thanks for the detailed summery.

Theres plenty to choose from there !

 

You're welcome. That's only half of them lol!

[+Streetbob]

Brilliant a full review of products.  Thanks 

[+Streetbob]

6 hours ago, Bino-viewer said:

Thanks for the detailed summery.

Theres plenty to choose from there !

That will be the problem, making a choice. 

[Nightspore]

10 hours ago, Streetbob said:

Brilliant a full review of products.  Thanks 

 

You're welcome. FLO are selling the Long Perng Amici for a reasonable 69 quid. They also sell the WO.