Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Regal 65ED M2: My review

  • Please log in to reply
7 replies to this topic

#1 Riccardo_italy

Riccardo_italy

    Viking 1

  • -----
  • topic starter
  • Posts: 674
  • Joined: 29 Sep 2014
  • Loc: Italy

Posted 17 August 2019 - 04:02 PM

It's about two months that I'm playing with a Regal 65ED M2. Yes, it's a spotting scope, a well made one, not too expensive and compatible with standard 1.25" eyepieces. Here my impressions. English is not my native language, so forgive any mistake.


Intended use

A spotting scope is a refractor plus a 45° erecting prism in a rugged and lightweight package: nothing prevent to point it at the sky. However, the 45° prism is not as comfortable as a 90° star diagonal to observe (but it is much better than a straight through binocular), there is no (easy) system to add a finder or a red-dot and you are limited to 1.25" eyepieces. I think a spotting scope excels if you need a travel, sturdy, grab&go refractor to be used for both nature & sky observations (even if the sky part will get most of the use).


reg2.jpg
How small all the package (tripod + scope) is. The ES 5.5mm 62° is for comparison.


Specs

A 65mm ED spotting scope, with internal focusing and a magnesium housing. Sort of mid-quality zoom: 40°- 62° but with a large eye-lens and a much better eye-relief (20mm spec, can be used with my not-too-thick glasses) than the cheap models. Need refocusing when changing magnification. Weight is incorrectly specified: a bit more than 1600gr, and not the stated 1327gr. 


Mechanics

The scope has a major mechanical problem: it is back-heavy and it cannot be balanced with a short dovetail. The unbalance is severe, and it makes challenging using the scope on whatever mount, unless with a payload (and weight) that largely exceeds the scope's one. However, the problem can be solved. You need at least a 15cm long dovetail (I use an Arca Swiss one). Luckly, the dovetail can be fixed to the scope using two thumbscrews, so it stays firm once fixed.

reg3.jpg
The scope with the long dovetail bar


reg4.jpg
Note (i) the two thumb-screws to connect the scope to the dovetail and (ii) how far back the clamp locks the dovetail


Changing eyepiece is not as easy as in a traditional diagonal. There is a self-centering ring and, once you have turned it, some force should be used to pull-out the eyepiece. I think that's normal, as in that way all the system remains waterproof (there is at least one O-ring where the eyepiece is inserted).


Very nice the metal made "case" for the eyepiece, which screws directly on the scope and fully cover the zoom eyepiece (and whatever smaller eyepiece you put there).


The back part (diagonal + eyepiece) can be rotated. Hence, it is possible to mount the scope on a ball-head (see below).


CONTINUE



Edited by Riccardo_italy, 17 August 2019 - 04:04 PM.

  • Mark9473 and Castor like this

#2 Riccardo_italy

Riccardo_italy

    Viking 1

  • -----
  • topic starter
  • Posts: 674
  • Joined: 29 Sep 2014
  • Loc: Italy

Posted 17 August 2019 - 04:15 PM

Eyepieces compatibility

 

I have tested:

 

1) The zoom eyepiece (it is obviously compatible). Works best up to 30x (more or less), then the image gets softer.

 

2) Wide field. A 16mm 68°, for (almost) 24x and 2.85° FOV. It focuses at infinity. This FOV is greater than the maximum FOV provided by the zoom eyepiece (2.5° @16x). All the field is illuminated (I have tested it using two stars with a separation slightly greater than 2.8°). However there is some vignetting: the edges are not as bright as the center. As I can detect it visually, the vignetting should be equal or greater than 20-30%. If someone has the same scope and it can test a 20mm 68° or something similar, I would love to see the results. I guess the scope can arrive up to 3°, more or less

 

3) Max magnification. I have tested a 5.5mm 62° for (almost) 70x. It works: it focuses at infinity and the image is usable. Not so good on low contast targets like Jupiter (but Jupiter always wants low mags w.r.t. the scope diameter), very good on the moon (the entire moon is entirely framed, barely) and on bright stars.

 

CONTINUE


Edited by Riccardo_italy, 17 August 2019 - 04:15 PM.

  • Castor likes this

#3 Castor

Castor

    Apollo

  • *****
  • Posts: 1350
  • Joined: 26 Mar 2008

Posted 18 August 2019 - 02:08 AM

Hi Riccardo,

 

Excellent, very thorough and well-structured, nicely illustrated report on the Celestron Regal M2 65ED Spotting Scope! waytogo.gif

 

I’m sure it will be very helpful for people considering this scope as a dual purpose for astro/terrestrial use.  I own its larger brother (100ED) and concur with your observations, even to the issue of having to apply some force to insert or remove an eyepiece and the odd distribution of weight at the point of attachment for a tripod (the foot), mine is front heavy.

 

I use the Regal M2 100ED as a stationary spotting scope at home and since my limited area of observation lies at a similar average distance (about 1 km or 0.6 miles away) I use a Pentax 8.5 mm XF eyepiece (64X) because of its good eye relief (18 mm), nice apparent FOV (60°), decent quality (main issue is some field curvature) and modest price in the U.S. (USD $129.00).

 

Clear skies and keep up the good work! wink.gif 



#4 Riccardo_italy

Riccardo_italy

    Viking 1

  • -----
  • topic starter
  • Posts: 674
  • Joined: 29 Sep 2014
  • Loc: Italy

Posted 18 August 2019 - 02:46 AM

Mounting

 

In another discussion, someone suggested that "If your spotting scope has a collar ring that can be rotated by 90 degrees then a 36-44mm Arca-Swiss ballhead used in alt-az config (rotated into the notch) is solid and cheap."

 

I agree. I bought a relatively unknown chineese tripod on Amazon (https://www.amazon.i...e/dp/B01H0BKXKS), and it works perfectly up to 70x magnification. With the long arca swiss plate I have, I can perfectly balance the scope. Movements are fluid and I do not have to lock the ball to fix the scope in a given position. The ball head (a clone of the Benro B1) has the main lock and a friction adjustment, plus the pan lock.

The friction adjustment (which is gradual and works as you can expect) is useful. You do not need that when the tripod is perfectly levelled on a flat surface but, as my garden is not flat, when the tripod is not levelled it's useful to have a small amount of friction. I do not have that on the pan movement and, as a result, sometime there is a little slip (The pan-lock is a sort of on-off).

 

Optical quality

 

Very good. Yesterday night I wanted to took a picture of a bright star as seen through the eyepiece. Of course it was cloudy! I will try to do that and post here the result.

Star test is surprisingly good (at least at the the low magnifications used). Intra and extra focal images are similar, the diffraction rings can always be seen.

 

The scope is collimated (checked with a chesire).

 

Flashlight test: the scope works at full aperture (65mm). NB: the 65mm is an f5.9. The 100mm has a more obtuse light cone at f5.4, not sure if that might stop down a little bit the aperture of its bigger cousin.

 

The scope (and/or the zoom eyepiece) is very sensitive on your eye's position: if it is not perfectly perpendicular, it introduces some CA. If the head is perpendicular, CA is low (at relatively high magnifications) to almost non-existent (at low magnifications). This effect can clearly be seen on Jupiter for example: if the head is not perpendicular and at 48x with the zoom eyepiece, there is a light violet halo on one side of the planet which disappears when you put the head in the proper position: I have never seen such thing before. PS: on Jupiter you can see NEB and SEB plus the 4 satellites, and the zoom at 30-35x is better than the ES5.5mm at 70x (this evening I will test with a 10mm plossl at 38x).

 

CONTINUE


Edited by Riccardo_italy, 18 August 2019 - 02:52 AM.

  • paulsky and Castor like this

#5 Riccardo_italy

Riccardo_italy

    Viking 1

  • -----
  • topic starter
  • Posts: 674
  • Joined: 29 Sep 2014
  • Loc: Italy

Posted 20 August 2019 - 01:19 AM

Star test #2

 

I checked again the star test, using the ES 5.5mm 62°. I confirm the scope is collimated. No color in focus using a bright star. Both inside and outside focus, the concentric rings can be seen, even close to the optimal focus position. Here the external concentric disk is thicker. There is a very slight green color inside focus. Overall, IMHO the star test is good, expecially for a spotting scope.

 

Daytime use

 

reg-d.jpg

 

Very good. No CA (at least for normal targets, I have not tried to look at antenna or similar things, more at birds, trees and landscape).

Very comfortable to move around on the tripod. For daytime, I only use the zoom, it is not convenient to change the eyepiece every time. I still have to do some serious birdwatching with it.

 

Conclusions

 

There is at the moment an heated discussion on Cloudynights about spotting scopes. I can only confirm my initial impressions: for a dual day&night scope, a good quality spotting scope is, IMHO, a very good choice. The scope performs nicely also for astronomy, and not only for daytime use. I do not agree with people that says a spotting scope cannot be used for astronomy.

It is true, a 60-72 ED doublet with a 45° erecting prism and a zoom eyepiece can also be used for daytime observations, and of course with a 90° star diagonal it is more comfortable during the night. But:

1.  I know they exists some very expensive astro-quality 90° erecting prism, but I do not know of very good quality 45° erecting prisms which can be used with a telescope. The risk of loosing optical quality in daytime is there.

2. A telescope is less robust, heavier and not waterproof. For daytime use those are important weakness.


Edited by Riccardo_italy, 20 August 2019 - 01:20 AM.

  • paulsky, zjc26138 and Tyson M like this

#6 paulsky

paulsky

    Apollo

  • -----
  • Posts: 1249
  • Joined: 17 Feb 2004

Posted 21 August 2019 - 11:03 AM

Riccardo,

 

What is the maximum magnification that provides quality, contrast and sharpness in daytime use?

 

….And during the astronomical observations with the eyepiece zoom as standard, with those 16X-45X how are the celestial fields (at 16X)?

 

Thank you,

Paul


Edited by paulsky, 21 August 2019 - 11:04 AM.


#7 Riccardo_italy

Riccardo_italy

    Viking 1

  • -----
  • topic starter
  • Posts: 674
  • Joined: 29 Sep 2014
  • Loc: Italy

Posted 21 August 2019 - 04:49 PM

Hi Paul. At 16x the field is sharp, but the AFOV is narrow. The long eye-relief makes it feeling somewhat less narrow than an ortho (specs say the field should be the same). In any case, for rich field I suggest a fixed eyepiece. For example, with a Morpheus 12.5mm you get the same field as at 16x with the zoom, but at 30x and with a 76° AFOV.

 

During daytime, there is the big problem of air turbolence. In summer time, with hot temperatures, seldomly you get a very transparent atmosphere, and as a result sharpness depends a lot on the distance of your target (the closer the target, the sharper the image). I would say that up to 30x the image is resonably sharp, given the limitations above. However, I will try it again an report here. There is no (or very very low) CA for daytime and on standard targets, it's really very well corrected for that.

 

PS: I try to be as objective as possible, but I'm really very satisfied of the scope.


Edited by Riccardo_italy, 21 August 2019 - 04:52 PM.

  • paulsky likes this

#8 paulsky

paulsky

    Apollo

  • -----
  • Posts: 1249
  • Joined: 17 Feb 2004

Posted 22 August 2019 - 10:00 AM

Thank you Riccardo for your kind reply.

Best,

Paul




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics