After removing the mirror, take a sheet of notebook paper, lay on the mirror and trace around the outer perimeter. The following is a 4.5-inch mirror which I center-marked earlier this year.

Fold the circle template in half, then quarter and then make a tiny hole in the center with any small sharp object. Now take a black Sharpie and “lightly dot” the center of the mirror, via the tiny hole. Now you are ready to replace the mirror and begin collimation. I’m not going to discuss collimation in this post, but have provided the following link from “High Point Scientific”…which is excellent.

A collimation tool will be needed: I use a homemade machined collimating tool (see below) which works great. However, consider a Cheshire collimating eyepiece which is not very expensive at all. I have a Cheshire eyepiece, but most often find myself using only my homemade tool. A laser collimator is not necessary.

https://www.highpointscientific.com/astronomy-hub/post/equipment-reviews/cheshire-collimating-eyepiece-guide

A couple photos of my Cheshire eyepiece as following which I also use on occasion:

While the mirror is out, it’s the perfect time to check if cleaning is needed.

The following procedure has allowed me to clean telescope mirrors with excellent results.  It should, however, be noted that your results may vary.  And mirrors coatings are very delicate, so be careful and use good common sense and care.  

https://rogerivester.com/category/how-to-clean-a-telescope-mirror

It has become almost impossible for me to now use a standard straight-through finder scope, due to the pain in my neck. Getting under a standard finder and in all types of contorted positions is just too uncomfortable. So, a 90º RACI (right angle correct image) finder is now essential.

I have one 90º Antares 7.5 x 50 correct image finder (as pictured below) used with my 10-inch Newtonian, but on other telescopes I still use a standard finder.

The Antares finders have a removable eyepiece. I often replace the standard finder eyepiece with a vintage 20mm University Optics Erfle for use as a 50mm wide-field telescope.

I use a “Rigel QuikFinder” in conjunction with my magnified finders:

The Rigel makes for an excellent pointer for the telescope, as it’s much better and easier than attempting to sight along the optical tube. I have two Quikfinders and a standard base on my all my telescopes.

The Rigel finders are fairly small and lightweight…better suited for smaller telescopes than the much larger and heavier Telrad. I also like the “higher profile” of the Rigel for greater ease to sight.

Rigel QuikFinder from Agena Astro as following:

A new GSO (8 x 50 RACI finder) arrives on December 9th 2025:

I purchased and received a 90º right angle correct image finder to replace an 8 x 50 straight-through finder.

I would have purchased another Antares finder with a removable eyepiece, but unfortunately several astronomy vendors were out of stock. And this is the time and season to observe with cold, clear and transparent nights…so no time to waste!

The quality of the Antares is superior to the GSO, but this finder is fine and will also work with my 102mm refractor or my 4.5-inch reflector. The focus must to be adjusted via the objective lens. The Antares is also adjusted with the objective lens, but the eyepiece can also be used to focus by pulling up or down for greater precision.

So, if you can wait…get the Antares finder, but a dovetail holder or (Schmidt-Cassegrain holder) must be purchased separately. (December 16, 2025)

For extremely faint deep-sky objects, of whichever telescope I’m using; a magnified finder is essential.

I first draw a circle on my atlas before going out with the same degree field as my finder. I then attempt to point the magnified finder to match that of my star atlas, with the deep-sky object in the center of the circle.

If the desired object is a very faint low-surface-brightness, such as galaxy NGC 6118…it can be very difficult using a star atlas and comfort is important.

Consider the following atlas page and circle, despite being so close to bright stars: Yed Prior and Yed Posterior the galaxy was invisible. I used the faint single star just to the north of the galaxy and it could not be seen. I spent hours on this galaxy over many observing sessions and seasons, attempting to see the galaxy. However, during moments of perfect seeing “I saw the galaxy” with averted vision, but not constant and only intermittently.

NGC 6118 is considered by most all amateur astronomers to be the most difficult object in the Herschel-400 list.

My suburban backyard is now averaging a naked-eye limiting magnitude of ~4.8 on my best nights, which is pretty bright; making very faint deep-sky objects difficult to find.

Patience and comfort is important when star-hoping to those very faint deep-sky objects…and as for me, a 90º RACI finder is now essential.

December 14, 2025

I’ve always liked or preferred a Newtonian for their simplicity and without the “mirror image” eyepiece view, as compared to a Schmidt-Cassegrain or Maksutov. I’m a visual observer and pencil sketcher, so I want my notes and sketches to present deep-sky objects with the ‘”cardinal points being scientifically correct” as they truly appear in the sky.

However, I use an amici diagonal (for a correct view) with my 102mm refractor and can use it with a Schmidt-Cassegrain also.

A 130mm (5.1-inch) Celestron Newtonian telescope with a computerized mount is capable of showing many deep-sky objects the first night out. No experience required…only reading the instruction manual and entering some basic information into the hand controller.

This telescope can be purchased from a variety of vendors for about $600, and is also sold under different names.

Newsflash! After careful review of other telescopes, I’ve picked a better value telescope for only $269 more than the 130mm 5.1-inch.

A much more professional quality telescope, mount and computer. This is a “lifetime” worthy telescope! So read on…

For those wanting a more precision mount with a higher quality telescope: The (NexStar 5SE) is a good deal; or a better deal. Yes, this is a lifetime “keeper” telescope for only $269 more than the 130mm Newtonian.

This telescope (Celestron NexStar) has a heavier and better quality mount and computer drive, which is the same as used on their 8-inch SC scope. After careful consideration, I now believe that the NexStar 5SE is a much better buy than the 130mm Newtonian.

Many say a 6 or 8-inch Dobsonian would be a better buy, but they require knowledge of the night sky. A telescope with a computerized mount allows the new amateur to see many deep-sky objects the very first night.

There is always time to purchase that 20-inch Dobsonian, but make sure you know just how large this telescope is before you make that purchase!

For those of us that have been amateurs for decades, we know that our “first telescope purchase” is just the beginning, with many more telescopes to follow. And if you decide that amateur astronomy is not your thing…there is always a need to have a telescope: This might include checking out a lunar eclipse, the rings of Saturn, Andromeda galaxy, the polar ice cap of Mars or even looking at the moon.

The value of a GoTo mount:

The most difficult part for the beginning amateur astronomer is locating and finding deep-sky objects, and I say this from experience. I remember being 12 years old, using my brothers 60mm refractor and wanting to see some of the beautiful and dazzling deep-sky objects, I’d seen in my 6th grade science book. I would have to settle for the moon, as it was pretty easy to find. 🙂

I didn’t have a star atlas at that time, but wouldn’t have known how to use it. I’m just glad I stuck with it as one day I would learn enough to become a real amateur astronomer. My “mostly astronomy” blog site as following:

https://rogerivester.com

By popular demand…I’ve included a 6-inch Dobsonian for $449.00 and an 8-inch for $629 as excellent first telescopes. The following telescopes are sold by Astronomics, but similar versions can be purchased from most any astronomy vendor.

“On Public Nights at Allegheny Observatory, when the dome of the 13-inch refractor is crowded with visitors, all anxious to look at everything in the sky, a handy finding list of impressive objects is invaluable.”

” These words prefaced our short list of celestial showpieces published in the December, 1962, issue of “Sky and Telescope.” We now present an expanded version….” James Mullaney and Wallace McCall

I’ve been wanting to compile an observing list of “only double and red stars” using a 4-inch or smaller telescope. I wanted a fairly short list that would allow for a more casual approach and to bring back memories from my earlier days as an amateur. I’m also anxious to begin observing double and red stars again, which are perfect targets for suburban observers, as light pollution and a bright moon has little effect on these objects.

From February 2009 until June 2024, the Observer’s Challenge report consumed most of my time as related to observing. The report began in Las Vegas with Fred Rayworth, but the last five years were with Sue French.

The original objective was to promote visual observing, notes and pencil sketching, but with so few visual observers it became more imaging. It’s my opinion, based on my experiences, and with many astronomy clubs over the past 30 years, pencil sketching is “pretty much” nil or naught in amateur astronomy these days or currently.

The “Finest Deep-Sky Objects” was one of my very first deep-sky reference books, which makes this effort special. The FDSO’s contains 57 double and multiple stars, 4 red stars, 10 open and 11 globular clusters, 12 planetary nebulae, 3 diffuse nebulae, and 8 galaxies.

For this project, I will use only the 57 double/multiples and the 4 red stars listed in the book. The most difficult of the double stars is Sirius, but now (2026) with the wide separation is a great time to attempt this one really challenging double. I’ve seen Sirius B with a 102mm f/9.8 Vixen refractor, 102mm f/8 FS Takahashi, and a 10-inch f/4.5 Newtonian with a 5.25-inch effective aperture.

So, I am wanting to go back and “maybe feel” some of the excitement I had while using my first telescope: A 4.25-inch Edmund EQ reflector…when all deep-sky objects were new to me.

My 4.25-inch Edmund reflector is pictured below which I purchased in March 1977. I have so many fond memories using this telescope.

Since I no longer have the Edmund reflector, I’m planning to use a 4.5-inch f/8 reflector, which was given to me by a friend, earlier this year (2025). I thought oh no…I don’t need another telescope, but took it anyhow. I’m glad I did, and after center-marking the primary mirror and collimating, I was surprised how good it performed. And it’s also in pristine condition, with a really nice black/charcoal metallic paint job, with a clear coat! So, little did I know that six-months later I would attempt the “61 Finest Double and Red Stars” with this telescope.

I’m thinking that this telescope will or should perform similar to the Edmund reflector. Excellent collimation is essential for double stars. I’m anxious to get started and will begin the next clear night, but I’ll not be in any hurry, as the “fun is the journey, and not the destination.”

Note: There are a few of the double stars that have a separation too close to split with the 4.5-inch and will require that I use my 6-inch f/6 Newtonian or 102mm f/9.8 Vixen refractor. I will definitely leave out Sirius for obvious reasons.

The equatorial mount that came with this telescope was too lightweight and flimsy for serious deep-sky work. Fortunately I had a quality Vixen GP mount that works perfectly with this telescope. A simple sight-tube would have worked better than the original finder scope. Fortunately, I had an extra 8 x 50 quality finder. The quality of the optical tube assembly is actually pretty good, and I look forward to using this telescope.

I plan to use “only my vintage” University Optics Konig’s (pictured below) for my double star project. Since I’m trying to mimic my observations from more than 40 years ago, using a 4.25-inch Edmund reflector, these “less modern” but excellent quality eyepieces would seem more appropriate.

Beginning in August 1995, I began a comprehensive review of all 105 objects in the FDSO’s, but adding the Crab Nebula. Jim always said that M1 should have been included. So, I added and named my publication “The 105 (+1) Finest Deep-Sky Objects (Revisited)” and spent over 250 hours at the eyepiece. I finished or concluded my quest in May 1996, but then spending at least 50 or more hours to compile my notes for the self-published book. My goal was to complete the list within one year…which I achieved. I really underestimated just much time and effort this project would require.

My astronomy friend Tom English helped me compile and print the book. At one time, for about eight years we enjoyed many nights of observing together from my backyard. Tom, at that time was an astronomy professor at a local university and also enjoyed observing both double and red stars.

All of the 3 x 5 note cards, more than 400 of them contain notes and pencil sketches with all work being performed at the telescope eyepiece.

The FDSO’s list of double and red stars are as following:

1. Eta Cas
2. Gamma Ari
3. Alpha Psc
4. Gamma And
5. Iota Cas
6. Gamma Cet
7. Theta Eri
8. 32 Eri
9. Beta Ori
10. Eta Ori
11. Lambda Ori
12. Theta Ori
13. Iota Ori
14. Sigma Ori
15. Zeta Ori
16. Theta Aur
17. Beta Mon
18. UU Aur (Red Star)
19. 12 Lyn
20. Alpha CMa
21. Deta Gem
22. Alpha Gem
23. Kappa Pup
24. Zeta Cnc
25. Iota Cnc
26. Gamma Leo
27. Xi UMa
28. Delta Crv
29. 24 Com
30. Gamma Vir
31. Y CVn (Red Star)
32. Alpha CVn
33. Zeta UMa
34. Epsilon Boo
35. Xi Boo
36. Mu Boo
37. Delta Ser
38. Zeta Crv
39. Xi Sco
40. Beta Sco
41. Nu Sco
42. Alpha Sco
43. 16-17 Dra
44. Alpha Her
45. Delta Her
46. Rho Her
47. Nu Dra
48. 95 Her
49. 70 Oph
50. Alpha Lyr
51. Epsilon Lyr
52. Theta Ser
53. Beta Cyg
54. Delta Cyg
55. Gamma Del
56. 61 Cyg
57. Beta Cep
58. Mu Cep (Red Star)
59. Zeta Aqr
60. Delta Cep
61. 19 (TX) Psc (Red Star)

Latitude: +35º 15′ Time: 9:00 PM

Time: 9:12 PM

Time: 9:13 PM

Time: 9:14 PM

I was surprised to get a phone call at about at 9:45 last night (November 13th) from a long-time friend and amateur, Don Books. He told me that he was seeing some color from his home in South Carolina. I jumped out of bed, got dressed and ran outside, but visually couldn’t see anything from my suburban backyard. However, with a 3-second exposure, again from my iPhone 14, and some color began to appear. It was nothing like the previous but an aurora display none the less. I’m glad Don called, and I share three of those photos as following:

Time 9:56 PM:

Time: 9:57 PM

Time: 10:00 PM and the aurora was already beginning to fade:

A really good article in the January 2026 S&T Magazine P-12 (planetary nebula NGC 7662) by Stephen O’Meara.

I especially like this article due to Stephen using and referencing visual observations of this object by many of the great observers of the past.  This would include John Herschel, William Huggins, E.E Barnard, and then S&T columnist Leland S. Copeland. He then shares the observation by contemporary French amateur and “visual observer” Bertrand Laville using a 25-inch telescope.

I was introduced to this planetary through my first deep-sky reference book: “The Finest Deep-Sky Objects” by James Mullaney and Wallace McCall in the late 70’s.  However, my serious observations of this planetary did not occur until November 1992 using my “then new” 10-inch f/4.5 Newtonian.  I have made many observations of the planetary from that time. A 4-inch telescope will pretty much present the same view as a much larger amateur telescope…appearing only a small bluish disk.

#104. NGC 7662 is a small blue dot in a 6-inch, a bright blue perforated disk with the 13-inch at 290x, and a fine object in both 30-inch telescopes.  It has a 12th-magnitude central star whose seemingly variability has been explained as a seeing effect.  We have sometimes recognized the star in the 13-inch.  Mullaney and McCall 

It was Sue French invited and brought Bertrand to the Observer’s Challenge as well as many other international visual observers.  This report (November 2021) was one of the best and finest of the 185 monthly challenge reports, as following:

https://rogerivester.com/wp-content/uploads/2021/11/november-2021-observers-challenge-_ngc-7662-b.pdf

Who is Al Nagler?

What does “artificial intelligence” have to say about Al Nagler?

Albert “Al” Nagler was a highly influential optical engineer, entrepreneur, and amateur astronomer who founded Tele Vue Optics. The company, which he started in 1977, became a globally recognized producer of high-quality eyepieces and telescopes. Nagler passed away on October 27, 2025, at the age of 90. 

Key details about Al Nagler and his career:

• Nagler designed the wide-field “Nagler eyepiece” in the early 1980s. These eyepieces provided a larger, more immersive, and sharper field of view. His work is considered to have elevated the entire eyepiece industry.
• Nagler designed optical systems for astronaut visual simulators for the Gemini and Apollo Lunar Module programs.
• Nagler was an active member of the amateur astronomy community. An asteroid was named 10715 Nagler in his honor in 1999.
• Tele Vue Optics was co-founded with his wife, Judi, and later became a family-run business involving their son, David.
• Nagler held patents for several inventions, including optical products and safety brakes for electric motors.
• Nagler received a Lifetime Achievement Award from the Astronomical League in July 2025. 

I had the honor to meet both Al Nagler and his wife at the 2017 Southern Star Astronomy conference in April of 2017:

Al Nagler: 2017 Southern Star Astronomy Convention: Little Switzerland, North Carolina

I was so sorry to hear about Al Nagler’s passing:

It was the April 2017 Southern Star Astronomy Convention sponsored by the Charlotte Amateur Astronomers Club, when a scheduled speaker for the convention cancelled at the last minute.

I’m not a member of the Charlotte Club, but had helped them over a few years to fill speaker positions at Southern Star.

A new speaker was needed…and really quick!

The Charlotte club officer in charge of Southern Star contacted me about finding a new speaker and asked if I could help in finding “the perfect” person to fill this now vacant position.

A solution, as I already had someone in mind:

I knew that Sue and Alan French were attending NEAF at that time. So, I called Sue via cell phone, and asked if she would talk to Al Nagler and see if he was interested in being a speaker at Southern Star.

Al was indeed interested and both he and his wife, accepted the invitation. 

Al gave a fabulous presentation concerning “everything anyone would want to know” about eyepieces. I don’t think anyone would know more about the science of eyepieces than Al Nagler. The presentation, to say the least was excellent…so much so, I even took notes.

Al Nagler and his wife Judi…two great people!

I was able to talk with Al and his wife for extended periods during the event, and also enjoyed having lunch with them in the Wild Acres cafeteria.

Photo as following: Al signing my “1000+ The Amateur Astronomer’s Field Guide to Deep Sky Observing” by Tom Lorenzin at the April 2017 Southern Star Astronomy Convention in Little Switzerland, North Carolina.

My signed 1000+ by Al Nagler and the late Tom Lorenzin pictured below:

(310120) Mullaney = 2011 DR25 Discovery: 2005-12-01 / L. H. Wasserman, R. L. Millis / Kitt Peak / 695 James Mullaney (b. 1940) is an American astronomy popularizer who has written about observing the night sky with naked eye, binoculars, and telescope. A former Curator of the Buhl Planetarium, staff astronomer at Allegheny Observatory, and an editor for Sky & Telescope and Astronomy, he contributed to Carl Sagan’s Cosmos TV series.

Visual observing and locating deep-sky objects manually, making notes and drawing what I see via the eyepiece is fun. I don’t embellish my drawings, but only what I see and with no computer enhancements.

To locate my selected deep-sky objects, for the evening, I just match up my finder view with the atlas and attempt to point the scope at the exact spot.

I use different sizes of brass and steel rings to match my finder(s) field of view. My choice for the last 15 years plus have been the S&T Pocket Sky Atlas’ which are compact and easy to use in the field. The black stars are so much easier to use as compared to atlas’ with white stars on black backgrounds. Plus, I like the larger format pages of the Pocket Sky Atlas’.

If you will notice, I draw circles (on the atlas pages) are for my “selected” objects. I don’t mind all of the drawn circles, soaked pages from dew, which shows the atlas’ have been well used.

A few examples of my humble pencil sketches. I have more than 200 sketches using this format (5 x 8) and about 1,500 using much smaller 3 x 5 cards.