2" Star Diagonal Recommendations

[Hans Tucker]

Looking at getting a 2" diagonal having lost my Takahashi one. Tried viewing without one...how do the Japanese do it.

Looking at either the Astro-Physics MAXBRIGHT 2" Mirror Diagonal or the Vernonscope 2" (1/20th wave) Quartz Star Diagonal. Anyone had experience with one or both these brands and can provide feedback?

[Kunama]

Haven't used the Vernonscope, I have tried the AP which certainly is very nice. Personally I like the Baader Dielectric 2" ClickLock Hans. It is optically as good as any I have ever used and has the best mechanism for eyepiece clamping of any diagonal.
(Apparently tested to a minimum 1/10th wave accuracy after the coating is applied, other brands apparently test their mirror and then apply the coatings, although much of this is academic as our eyes can't differentiate at these levels of accuracy on a diagonal)

I also use a Zeiss Prism diagonal which is very nice but my reason for buying it was to shorten the light path.

There is a new Carl Zeiss 2" Prism with the ClickLock feature inbuilt but it is big $$$. Telescope Express have it on their site.

[SkyWatch]

You could also try the Televue Everbrite; I suspect it is the same as the AP anyway (AP stock and recommend a lot of Televue stuff), and it would probably be cheaper to get it from Bintel than getting an AP from the US.
I use the GSO quartz diagonal: I haven't noticed any image degradation compared with looking straight through on my TSA102... Good price at Andrews.
Mind you, that Baader/Zeiss set-up looks really nice, but for 4-5x the price...

All the best,

Dean

[PlanetMan]

I can't comment on the AP diagonal but I have had at three different occasions three different 2' Televue Everbrites diagonals. At the same time I have also had a common or garden 2' GSO quartz diagonal. Despite costing more than three times as much as the GSO diagonal I couldn't discern any differences (ie image superiority) from the Televue Everbrites over the humble GSO.

Ironically, if anything images generally seemed slightly brighter with the quartz GSO;) So, for pure optical performance the GSO quartz is the best buy under the sun (imho). The only real benefit that I can discern from the Televue Everbrite is the one piece design which provides you complete peace of mind that the barrel won't roll and unscrew if you are using any big heavy eyepieces.

[astroboof]

Good post, the one above. Have had numerous diags, WO quartz dielectric, a gso quartz dielectric, a gso dielectric, and a prostar dialectric, and regular. meade, and a couple of others. Mostly in 2" but a few in 1.25"

Never could really tell the differences between the lot of them, apart from when pollution appeared for cleaning. Beyond that, It's a bit of a wank imho.

All the above have been serviceable and tunable, the meade was the least impressive.

Also had a SW 2" (alleged dielectric) supplied with my SW ED100, it's a touch on the lemon side, just my humble opinion. ramble ramble.. save your hard earned..

[LewisM]

Agree on the SW 2" - absolute carp. The nosepiece would wobble all the time with mine.

TV... don't thrill me either. W.O Durabrite didn't rock my world (despite not locking properly in Tak clamps).

I do like my prism diagonals, and the humble Takahashi 1.25" prism diagonal is more than enough for me. It is all I have now, and I have no reason to change that. If I DO, it'd be another Tak or a Zeiss.

I did like the Lumicon made for Takahashi FSQ106 diagonal (screw on, short path) - going to try to find another.

[LewisM]

Hans: http://www.astromart.com/classifieds/details.asp?classified_id=890136