Which 2" diagonal

[MartinB]

I'm looking for a high quality 2" push fit diagonal. I would like to buy a "no compromise" piece of kit whilst at the same time not wanting to pay through the nose for a name. Seems like dielectric is a must and quartz seems to be something that bumps up the price although I don't know what the significance is.

So - do I go for a TMB Everbrite, Astro Physics Maxbrite, WO quartz dielectric (the most expensive of the bunch!) or a budget quartz dielectric with no brand name from FLO.

At the moment I'm thinking AP. With the current exchange rate it should work out cheaper than the TMB and WO.

Any advice?

[James]

I thought long and hard about getting a really good 2" diagonal for my refractor and considered the 'big names'. Steve @ FLO let me have a Quartz 2" Dielectric diagonal http://www.firstlightoptics.com/proddetail.php?prod=QD2incdiagonal on approval to see if I noticed the difference between the stock model on my scope and the new one. The first time I took it out the difference was pretty clear, not huge but noticeable. As I haven't tried an AP or Televue diagonal I can't confirm whether the difference between them and the one I have is of the same order of magnitude (no pun intended) but I can't imagine it is. I'll be sticking with the one Steve supplied...

James

[FLO]

The 2" Dielectric Diagonal at FLO is from the GSO stable and is the same spec' as at least one other expensive/prestigious brand...

[MartinB]

The 2" Dielectric Diagonal at FLO is from the GSO stable and is the same spec' as at least one other expensive/prestigious brand...

Now that's worth knowing! Does it open at the side for cleaning Steve?

[FLO]

No... Which one does that?

[MartinB]

I read that the WO diagonals open from the side which greatly reduces the risk of them going out of alignment after cleaning.

[FLO]

Clever 8)

[John]

I use a Revelation branded 2 inch dielectric diagonal which are very similar, if not identical, to the William Optics model. I've tried this back to back (so to speak) with a WO 1.25 inch dielectric and I can't detect any difference in performance in visual use. I used to own a Tele Vue Everbright and I can't remember that being any better than the Revelation. The Revelation has single piece removable sides / back plate for cleaning the mirror and are available for £69 from Astronomica.

John

[russ]

Well I've had the WO, Stellarvue and Revelation Dieletrics....all 99% reflectivity. Also had the Antares el cheapo £18 92% reflectivity diagonal. And have to say of all the telescope upgrades there are, diagonals are single most disappointing of the lot. Neither myself or Rob could see any marked improvement between the dielectrics and that cheapy Antares.

The Revelation that John linked too is terrific value for a 2" Dielectric. It's the most i would personally spend.

Just my opinion off course

[Brass n glass]

The only one I've ever used is a Televue Everbrite - superb construction and performance and now on sale at Ace in Bristol for £139, which I think is a lot less than the usual, er, astronomical price - Hugh

[MartinB]

Thanks guys, really useful advice. So nice to have impartial opinions from people who've used the kit.

[Father Ted]

Hi,

I use a TeleVue 'Everbrite' 2inch on my old Celestron 6inch Refractor. The difference this good quality diagonal made was very noticeable, but then the stock 1.25 diagonal that came with the scope was not exactly a shining example of cutting edge quality. The rack & pinion focuser was also junk, so that was replaced with an Antares Crayford focuser. These mods, plus some TeleVue Radians & Plossls, and an EQ6, have turned a fuzzy imaged wobbling jelly into a pretty decent scope.

Personally, I think that the TeleVue 2inch is superb. But then as I was daft enough to shell out a small fortune on it, I would say that !!

These days I would be much more inclined to have a good look at what FLO has under the counter :shock:

Greyfriar