Celestron Regal M2100mm scope (1 Viewer)

A question. Does anyone know if this scope would take a Barlow Hyperion zoom eyepiece? Thanks in advance.

Sancho, do you mean "Baader" Hyperion? If so I believe the answer is yes.

I use a 17mm Baader Hyperion on my Regal 80 and the results are truly nice!

Mark

Kammerdiner said:

Sancho, do you mean "Baader" Hyperion? If so I believe the answer is yes.

I use a 17mm Baader Hyperion on my Regal 80 and the results are truly nice!

Mark

Click to expand...

Thanks Mark! Baader is exactly what I meant, sorry.

The Hyperion zoom still might not work. It needs more infocus than the fixed Hyperions to reach infinity focus. Someone will just have to try it to know for sure.

henry link said:

The Hyperion zoom still might not work. It needs more infocus than the fixed Hyperions to reach infinity focus. Someone will just have to try it to know for sure.

Click to expand...

Yes indeed, Henry. I wrote that I "believe" it would work but perhaps I should have been more circumspect. Up for a try, Sancho??

The supplied Celestron zoom is really good I think. I wonder how much improvement the Baader would be?

Mark

Kammerdiner said:

Yes indeed, Henry. I wrote that I "believe" it would work but perhaps I should have been more circumspect. Up for a try, Sancho??

The supplied Celestron zoom is really good I think. I wonder how much improvement the Baader would be?

Mark

Click to expand...

Thanks chaps. How is the FOV on the supplied zoom, Mark?

Im almost sure the baader works on the previous 100 regal. I think there is no mechanichal and desing changes in this m2.

My zoom works very well up to the 67x, generous eye relief all the way ... aside more fov honestly i belive there is not a huge iimprove on the pure visual perfomance. One thing that is good, the celestron zoom gets the 60 afov very soon when you zoom it.I got 1.9 to 1 fov (or afov dont remember), like i said, in the new regal is the same

Sancho said:

Thanks chaps. How is the FOV on the supplied zoom, Mark?

Click to expand...

The supplied 20-60x zoom strikes me as having a fairly typical FOV, maybe a bit better than zooms common some years ago. It's not a WA in any case, but I got along just fine. Excellent eye relief throughout, though not quite like the newest WA zooms. I really liked the 27x WA view provided by the Baader. REALLY nice! With the zoom adjusted for ~27x I noticed no difference in sharpness between them, not much difference at all except the FOV. The supplied zoom really is a good one.

If I slipped into the past tense there it's because I'm using the Meopta S2 these days. I have the first generation Regal 80mm made of aluminum and it is BIG and HEAVY. As good as the Celestron is, I just didn't like carrying it. The M2 is lighter, but I don't know how much lighter.

I've been meaning to post up the Celestron in the classifieds and pass it along to a deserving soul, but I tend to be lazy about such things.

Hope this helps,
Mark

Thanks for the info folks. I´ve been eyeing up the Regal M2 100 ED online. A retailer here in Dublin can get it for me for 1000 euro. I don´t really know why I want it. My current set-up is the (old) Victory Diascope 85mm with a Baader-Hyperion zoom. I really like it, for reasons I can´t explain fully. (I had a Swaro ATS80HD 25-50x, but always regretted losing the little extra push beyond 50x, when I sold my previous Zeiss/Baader).
My rationale is as follows: While seawatching happily recently with my Zeiss/Baader, I looked through an old Optolyth 100mm (TBS, I think), that a fellow-birder had. I liked it. I figured that 100mm objective was doing things for my eyeball that even the 85mm of the Zeiss couldn´t. So I consulted Doctor Google, and found the Celestron. There aren´t many cold, clinical reviews of this scope out there, and no-one seems to have stuck a Baader-Hyperion on it. I e-mailed the guys at Celestron and they kindly and quickly responded, saying any 1.25" astro eyepiece will fit (whether it reaches infinity focus is another matter, but there are "fixes" demonstrated in earlier BF threads for this).
I imagine the Baader-Hyperion will give a wider FOV on the Celestron 100mm than does the supplied zoom ep, and I also imagine a fixed-mag Baader of about 30x would be excellent. It´s a thousand-euro gamble, and I´m rummaging through my optics closet daily to see what I can cash in! (I realise the premium option would be a Swaro ATX 95mm, but even if I had the cash, I hardly do enough seawatching to merit the spend.)

The first thing I would want to know about this scope is what the clear aperture really is. I notice the same eyepiece and prism housing is used in the whole series. That raises a suspicion that the model with the lowest focal ratio (the 100mm) may be mismatched with an undersized prism. The focusing system used here also tends to restrict clear aperture at close distances as a prism is moved out of its optimum position, It's possible that the clear aperture at infinity is no more than about 90mm and then shrinks to 80mm or less at close focus.

Can somebody who owns this scope measure the clear aperture at infinity and close focus? There are several methods I can pass along if you are unsure how to do it.

Thanks for the caveat, Henry. Food for thought.

henry link said:

The first thing I would want to know about this scope is what the clear aperture really is. I notice the same eyepiece and prism housing is used in the whole series. That raises a suspicion that the model with the lowest focal ratio (the 100mm) may be mismatched with an undersized prism. The focusing system used here also tends to restrict clear aperture at close distances as a prism is moved out of its optimum position, It's possible that the clear aperture at infinity is no more than about 90mm and then shrinks to 80mm or less at close focus.

Can somebody who owns this scope measure the clear aperture at infinity and close focus? There are several methods I can pass along if you are unsure how to do it.

Click to expand...

Not to get this off track but I was looking at either the 65mm or 80mm version of this scope. If they all have the same prism housing and eyepiece would this suggest the 65mm version would be the way to go? Or would the scope likely be optimized for the middle (80mm) version?

Calhoun,

When you look at the increase in magnification with the zoom in the three models you see that it matches the increase in aperture for the 65mm and 80mm models, but is about 10% lower for the 100mm model. From that alone you can deduce that vignetting by the prisms will be identical as a percentage of aperture for the 65mm and 80mm, but about 10% worse for the 100mm.

Henry

Sancho,
What did you prefer on the Optolyth, the extra light (if with the zoom 20-60 or 30-60x) or the extra power (zoom 30-90x)?
Why don't you go for the Optolyth 100? Eventually you can swap with someone that has one and want a Zeiss...
You can use also the Baader zoom on it - see http://www.pt-ducks.com/cr-telescopes.htm#Test of 100mm telescopes - getting higher magnification than with the Celestron 100.
On both solutions, you might consider to look at a 1.6x barlow cell http://www.pt-ducks.com/cr-telescopes.htm#Test_of_a_1.6x_magnifier - it's inexpensive and should be useful for seawatching.
You can also use this barlow with your present Zeiss combo but you need the baader 1.25 adaptor to the Zeiss. With this adaptor you can use also fixed Hyperion eye-pieces, at least the low power ones.

Sincerest thanks, David, great suggestion! That should keep me obsessing for another few weeks!

BTW, the 100mm Optolyth TBG I saw had, I think, a 27x fixed ep. so it was wide and bright. (Mind you, on the same day I found a Fea's with the Baader Hyperion on my old Diascope, so maybe I should leave well enough alone.)