Diagonal Decisions

[Patbloke]

I have never been 'totally stuck' on making an astronomy equipment purchase before! I will admit to procrastinating and sometimes taking an age to get there, but get there in the end I do!

I once owned a lovely used Revelation 2" dielectric coated diagonal which I now regret selling when I sold my Helios150... So I'm back in the market for a 2"!

I've put both the 2" Altair Astro lightwave premium £99 (Red) and the Williams Optics Dura bright £135 in the shopping basket on several occasions but I really cannot decide which to buy... Luckily cost is not an issue as I've recently acquired funds from some Astro sales so the decision is to be made purely on standard and performance.

There are quite a few posts on here about the subject... But it's really driving my bonkers! I reckon the Altair will be a great diagonal but the WO is more expensive and has good write ups.... Heeeeeeeeelp!

Plus it's cloudy out there and I've just finished my Balti for 1 and need an Astro chat fix.... So how about a Poll?

[John]

I doubt is there is much, or anything to choose between them. They might even be made by the same manufacturer. I've owned a couple of William Optics 2" diagonals plus others by GSO/Revelation and could not see any difference in the performance to be honest. The Altair and the WO are both in the same "mid-price" niche I think.

Not enough "data points" for me to complete your poll I'm afraid !

 

[johninderby]

My heart says go for the WO but my head says it doesn’t matter which one. ?

Of course there is still the Revelation Quartz. ?

https://www.harrisontelescopes.co.uk/acatalog/revelation-quartz-dielectric-diagonal-2.html

[Paul67]

I just bought a Altair 2" dielectric  from Knighty2112 (thanks Gus!). This thing is a beast and extremely well made, very pleased. The locking mechanism for the eyepiece is very nice too, much better than single straight through screws.

[johninderby]

Then there is the Opticstar version. Looks a bit similar to certain others.  ?

http://www.opticstar.com/Run/Astronomy/Astro-Accessories-Telescopes-Opticstar.asp?p=0_10_5_1_8_211

 

 

[Highburymark]

On 03/10/2018 at 21:27, John said:

I doubt is there is much, or anything to choose between them. They might even be made by the same manufacturer. 

 

This matches my experience too. When I first upgraded from a Celestron stock diagonal to a WO dielectric, the difference was really clear. Then when I acquired a Skywatcher dielectric later - which was much cheaper than the WO, I could see no difference between it and the WO. Go for the cheaper Altair - a great way to upgrade your kit

[johninderby]

The Opticstar is cheaper than the Altair. 

[Panda Alvin]

I own an WO dielectric, and have also seen an Altair Lightweight up close.

Even from a detailed glance, both look very very similar, I won't be suprised if the base frame or components comes from the same factory, and apply the finish to the clients specifications.

In terms of performance, I haven't visually compared it to give you a definitive answer, but I think they are on similar level.

Also as a heads up,  the new WO dielectric model may (or maynot) come with a thermometer on one of the carbon fiber plates, even if it is not advertised. So you could add that to your deciding factors you are into that gimmick, but ask the supplier first to be sure though before if you end up do buying the WO one. 

[Moonshane]

I am not keen on the bevelled nose on these or similar eyepieces. I prefer a straight nose really. Thankfully my choice, the Baader prisms, are modular and allow choice in this respect. That said, they do vignette wider field stops a little.

[Patbloke]

Superb responses thank you... I forgot to select 'notify' for replies so I've just have the pleasure of reading these in one go! ?

Quartz JohninDerby??? Noooooo Are quartz any better what does that mean?

It's great to see it's not just me with the old diagonal dilema... I still haven't decided but I like the Altair... looks solid and says it's the old 99% reflectivity. 

I'm going to have to look at these quartz fellas now!!!

[Patbloke]

Actually the Optic star looks the same apart from colour and printing! Cheaper as well... and Black to match the scope ?

[johninderby]

I have one of the Quartz and a WO and had an Opticstar and couldn’t really see any difference.between them. Quartz is more stable under temperature changes so theoretically has an advantage but in the real world with the small mirror used in a diagonal  not going  to make much difference.

 

[Mr Spock]

I use the Revelation Quartz. I don't think anything is better, regardless of price.

[RiponJas]

I have the Altair diagonal and think it is a solid quality item. Haven't tried the other but it certainly upgraded my viewing pleasure from the stock item that came with my scope. ? 

[cotterless45]

C'mon mate , you've only given us half the story. You need the very best to go on here ! Then you can come around mine for another awesome testing session ! I'd go WO , which we tried out last session.

old Nick.

[johninderby]

Astrophysics. With a one piece machined body and no separate barrel to come loose. Slight problem though. £££££££££££. Although as close to perfection as you can get would the difference be noticeable in real world use?

[John]

11 hours ago, johninderby said:

Astrophysics. With a one piece machined body and no separate barrel to come loose. Slight problem though. £££££££££££. Although as close to perfection as you can get would the difference be noticeable in real world use?

I have one of those - very, very nice piece of kit

It's dedicated to my TMB/LZOS 130mm F/9.2 triplet. I thought that scope deserved something special !

The Tele Vue Everbrights are also one piece units, but also rather expensive compared to many discussed here.

 

[JTEC]

I’ve used the WO and the Astro-physics Dielectric with my TEC140 and other scopes. The AP was very solidly built and robust but optically had no advantage over the WO. And I am a very fussy observer!  Both were comfortably outperformed by the Baader Zeiss spec prisms, which I now use. (See Bill Paolini’s review). Trouble is they are expensive, but unsurpassed imv. 

[John]

1 hour ago, JTEC said:

I’ve used the WO and the Astro-physics Dielectric with my TEC140 and other scopes. The AP was very solidly built and robust but optically had no advantage over the WO. And I am a very fussy observer!  Both were comfortably outperformed by the Baader Zeiss spec prisms, which I now use. (See Bill Paolini’s review). Trouble is they are expensive, but unsurpassed imv. 

I have a Baader Zeiss on my Tak FC-100DL. I have compared it to my AP Maxbright of a few occasions and can't see any difference in performance at all, let alone a comfortable difference. I'm obviously not as fussy an observer as Bill or yourself !

 

 

[JTEC]

Well, John,  maybe saying ‘comfortably’ was a bit of an overstatement ... sorry!  I do see a difference though - better contrast, less scatter.  I bought the AP when I bought my TEC believing it to be the best around and a good match for that scope. It remains, to my eye, the best mirror diagonal I’ve used; the WO though less ‘built like a tank’ wasn’t at all bad optically. Improbable as it may sound, I began to suspect that the much-vaunted protective layers to which the AP owes its durability were making a contribution of their own to the image. Tiny though the depth is in everyday terms it is perhaps not negligible in relation to the behaviour of light entering the coatings and return-exiting them. A professional optical worker friend whom I consulted felt this was at least possible. I don’t know whether the idea holds water, but I clearly prefer the performance of the Baader Zeiss prisms in 1.25 and 2” in the TEC and C11, mono and with the binoviewer. That said, Bill P, in his review, speaks very highly of the silvered Baader mirror! I’d love to try one, but there comes a point when the spending has to stop! ?

John E

 

[John]

2 hours ago, JTEC said:

.... but there comes a point when the spending has to stop! ?

 

 

Yes indeed !

I have tried to get the best quality stuff that I can but I've always consoled myself by thinking that, if push comes to shove and I have to sell the premium stuff, the quality of the lower cost alternatives has reached the point where you can still get a lot of enjoyment from the hobby with a lower investment in it.

 

[Patbloke]

Fellow SGL contributors... I have BREAKING NEWS!!!!

I have finally broken my 'Diagonal Dilema' and made a purchase!!

After all the advice and agonising over the Williams Optics and the Altair Astro.... I've found myself a pre used Baader 2" Maxbright Ceramic mirror diagonal... At just less than a third of the advertised online price, and after seeing several photos showing at least the outside condition...  I've taken the plunge! I don't know whether it'll be that good and what's the worst that can happen? I've been assured by it's former owner it's great quality...

So there you go, not sure if anyone mentioned ceramic mirrors? I also had the option of a Baader prism diagonal but it would have worked out much more in price adding a nose piece and adapter...

I'll report back after I've used it and who knows might even be able to do a direct comparison with the Williams Durabright next time out with Nick?

But for now just feel my relief.... NOW what's next on the shopping list? ?

 

[John]

That looks to be a lovely diagonal

Sitall is a crystalline glass-ceramic I understand. Supposed to be very good material for mirrors.  

[JTEC]

Looks good!

And I have a suggestion for your shopping list ... if that isn’t a Baader Clicklock eyepiece holder shown in the pic, I’d respectfully suggest that one of those could come next ?. One click to lock, one click to release, even, secure, no screws etc, just excellent and not too pricey. You’ll never look back.

John E