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Choosing The Proper Binotron 27 Super System

Whether you own one or more telescopes, The proper Binotron -27 Super System will guarantee that they all reach focus and provide 3 magnification factors with one pair of eyepieces. There are slight differences in the versions below. Why? Ex: You may have a refractor, but do not intend to ever own or use a Newtonian. Perhaps you only have an SCT. Then, many observers have a refractor, SCT and Newtonian. It should be noted that most systems overlap and work with other telescopes and it can be a bit confusing for those who are not very familiar with how the Binotron Super Systems function when it comes to picking the ideal system for their stable of telescopes. So, in this section, we will try to provide some guidelines that make your choice clear and easy. Below is a list of telescope types and the ideal Binotron 27 Super System for those instruments. Please feel free to call us if you still have questions because we can help you make the very best possible choice! Just call us 10AM-5PM EST on our Cell: 410-251-4052.

Whatsapp contact is the same number: 410-251-4052  Email Us Directly : or

A Word About Microscope Heads and Prisms

Microscope prisms are typically made with Non-Polarizing beam splitter walls. The coatings on the beam splitter wall reflects and

also transmits the light that enters the binoviewer. In the best outcome, 50% of the light would be reflected to the right side, and

50% of the light would be transmitted upward and then moved to the left side of the binoviewer. With a microscope head that has

been converted for astronomy use, there will be a 10% loss of light at the beam splitter wall. This is because the beam splitter

wall coating is a hybrid Metal/Dielectric coating. This is used because light loss is not crucial in microscopy. An artificial

illumination source is used to light up the subject being viewed. So, control of polarization is preferred and the use of this hybrid

metallic coating on the beam splitter wall is employed. However, in astronomy where precious light is scarce and the source of 

this light is produced by the subject itself, a 100% dielectric coating is a must if virtually all of the incoming light is to be

preserved! Our Binotron 27 Beam Splitter is and always has had a 100% Dielectric Coating. We build this binoviewer from 

scratch including the body, all machined parts and the prisms. If the Binotron 27 is kept level and not tilted, polarization is 

successfully controlled. Now you know the real story! See this link for more on the subject:

The bottom diagram shows transmission and reflection of a hybrid beam splitter coating 

You WILL lose 10% or more of incoming light on such a coating!

Telescope Types and the Best Binotron-27 Super System for Them

Newtonians and Other Scope Types  

The Binotron-27 Super System (1099.00) with Upgraded OCS A45 (149.00) is the ideal choice for all Newtonians.  

This system is really the only choice if you intend to use a Newtonian. This system also works on Refractors and SCTs

and many other related telescope designs. The OCS (Optical Corrector System) leads the way into your focuser and

intercepts the converging light cone of the telescope first. This light cone is the widest at that point of interception as it

travels to, and through the binoviewer to the eyepieces. The OCS is necessary in order to produce focus. One may

get away with not upgrading the OCS A37 to the A45 if the Newtonian is slower than F/5.  What is the difference between

the A37 and A45? The OCS A37 has a 37mm clear aperture. The OCS A45 has a 45mm clear aperture and is the

largest optic we could fit within a two inch holding cell. The Binotron-27 Super System allows a single pair of eyepieces

to experience a 1.3X/2.3X/3X magnification factor whether one used the A37 or the A45. The A45 will bring in peripheral

rays that would otherwise be lost with the A37. Options include The Filter Switch (249.00), The Collitron Reticle (139.00),

our highly acclaimed D21 and D14 Conventional Eyepieces, and the new L-O-A 21 3D Eyepieces available through Buy any Binotron -27 Super System and get a 150.00 discount on the 3D Eyepieces!

Refractors Only

The Binotron 27 Super System (1099.00) will operate with your own 2" Star Diagonal and allow your refractor to focus

at three magnification factors. The included OCS A37 is fine for using with most refractors because the converging rays

are not so steep since focal ratios are typically slower than F5. Refractor telescopes in general MUST have the OCS

threaded to the telescope-side of the star diagonal in order to allow the Binotron to reach focus. There are some

advantages to using our own Denkmeier 2" Quartz Mirror IVB Star Diagonal (we provide more details under that

product description). However, any 2" Star Diagonal threaded for 48mm filters on the telescope side (virtually all modern 2" Diagonals are threaded) will allow the Binotron to function at three magnification factors with no problems reaching focus. If you also plan on using this system with a Newtonian, we recommend upgrading the OCS A37 to the OCS A45 (149.00 for the upgrade at time of purchase). And yes, this system works with SCTs as well. 


1.The Binotron 27 SCT Super System (1399.00) includes everything that the Binotron 27 Super System does but in

addition, the IVB 2" Star Diagonal is also included. The dovetail system is included also. This allows the Binotron to

be "docked" to the diagonal body after the 2" Star diagonal eyepiece holder is removed. This configuration can come

in handy if your SCT has less back focus ability. Dovetailing lessens focus demand when in reduction .66x mode. For

most SCTs, this system allows ..66x/1.15x/2x  magnification factors. This system also includes everything needed

for refractor use including the 2" Star Diagonal. Yes, this system also works with Newtonians though adding the option

for the upgraded OCS A45 is highly recommended.

2. The S2 Power Switch Star Diagonal and The Binotron 27 Ala Carte  is also a very good option for SCT users.

The positive side of this is that since the large 37mm clear aperture lenses of the S2 Power Switch are in fact ON

the S2 Diagonal and not the  Binotron, even 2" Single Eyepieces can be used in S2 for Reduction/Normal/Barlow

magnification changes. A limitation is that a Newtonian Telescope cannot reach focus without a Power Switch

and OCS being on the Binotron 27. The Binotron Ala Carte connects to the S2 Power Switch Diagonal and will

not focus in a Newtonian.The S2/Binotron Ala Carte is strictly for SCT users. Note that the S2 and Binotron 27

Ala Carte can be used with a refractor if the OCS A45 Option is added to the S2. Many SCT users choose the  S2

and The Binotron 27 ALa Carte because the S2 can also be used to allow Power Switching for single eyepieces,

especially 2" widefield eyepieces. The magnification factors are basically .66x/1x/2x. These are approximate values.


Solar Scopes

Lunt Solar Scopes: All of the above except for the Binotron Ala Carte and S2 will work for the Lunt 60mm and above

Hydrogen Alpha Scopes. However, you must add our Denkmeier Optical Adapter for Lunt Scopes (249.00 option). See this product under Shop for more specific details.


Binotron 27 for The Quark from Daystar: We like the Binotron 27/Quark combination so much that we and Daystar are working together on a bundle package! See the Bundle Package under Shop for more details. The Binotron 27 used with The Quark has a dual arm power switch just like it does for the Super System. This allows three magnfication factors when used with The Quark. There is no OCS Cell included with this version since it is not used with The Quark. The Quark has an internal 4x transfer lens but The Binotron 27 Power Switch low power lens allows full disc views with our Denkmeier 32mm Plossls.  Included in the Binotron 27 for The Quark  is The Binotron 27 and a pair of our new Denkmeier 32mm plossls. The Quark Solar Filter from DayStar is additional. 

This Section Contains "No-Frills" Videos That Provide Information About Our Products

                                                  If you are viewing with a cell phone, the videos are found after FAQs


















L-O-A 21 3D Eyepiece Description                                      Binotron 27 Power Switch                                                                       Denkmeier Optical IVB Star Diagonal
















The Dovetail Connector                      Focusing A Binotron 27 in a Newtonian                                  About The Binotron 27 Eyepiece Holders













 The Dovetail Connector: Set vs Thumb Screws              Collimating The Binotron 27 With Collitron Reticle                       Removing The Filter Switch
















               Using The Collitron Reticle                                          Using The Dovetail Connector                                            The Filter Switch














        Adjusting Interpupillary Tension                           Special Star Diagonal for Takahashi Old FSQ                 Part SR For TV EB and AP MB Diagonals 













       Focusing Your Newtonian w/Binotron 27










Binotron 27  FAQs

Thank You for visiting this section. We will be adding information as time goes on.

Q:Why Buy A Binotron 27? IT's MORE Expensive!

A: There are many objective reasons to choose a Binotron 27. Our Beam Splitter has a pure 100% Dielectric Coating. This means there is virtually NO light absorption at that all important wall! Microscope heads and other less expensive binoviewers that are converted for astronomy use have HYBRID METALLIC COATINGS on the beam splitter wall to prevent Polarization. Microscopy provides it's own light source that illuminates the subject and does not need to be concerned with a 10% absorption rate of the light. They can simply INCRESE the brightness of the light source. However, for the mostly feebly illuminated astro objects that we view, a 10% light loss is HUGE! Polarization is not a problem if the binoviewer is kept parallel and not rotated. One should not rotate the binoviewer anyway when viewing! Also, aside from the 1/12 wave flat prism quality and the 26mm CLEAR APERTURE PRISMS (all that is required for astronomy and making larger prisms increases the light path needlessly), our patented Power Switch and OCS (Optical Corrector System) assures focus in ANY telescope and  at three instant magnifications with ONE PAIR OF EYEPIECES! The real question is Why Would Anyone Choose a Different Binoviewer for their amazing telescope? I have put 17 years of full time work and knowledge into the design of our Binoviewers, Correctors and eyepieces. Be assured that the finest points have been integrated to produce the highest quality Binoviewer System in existence.

Q: What is the Minimum and Maximum Interpupillary Fold Width of The Binotron-27?
A: 52mm is the minimum, 80mm is maximum.

Q: Is the Binotron-27 Body a converted microscope head?
A: No. The Binotron-27 has been designed from start to finish by Denkmeier Optical. We own the mold, made the mold, and utilized 15 years of experience to design a binoviewer specific to astronomy with the most innovative features anywhere.

Q: What is the warranty and is it transferable?
A: Our warranty is good for one full year from date of delivery. The warranty is not transferable. We urge you to buy new, not used. We cannot do tech support on used products. 

Q: My Interpupillary tension is loose enough so that it folds downward with eyepieces installed. Is this normal?
A: This tension is easily adjustable. Please see the instructions below:                              

Q: What are the weights of the various parts?
A: This photo below provides weights in both grams and ounces. For The BINOTRON-27 Super System, one would add the weight of the BINOTRON-27 Body, The Bino Power Switch, The 2" Nose (not pictured: 50gm/1.7 oz), The Middle Newtonian Spacer (if using a Newtonian), and the OCS A-37 or OCS A45 if being used. Note that the OCS A45 actually weighs a bit less due to the thinner walls of the Aluminum Cell. So as an example, The complete BINOTRON-27 Super System ready to be used in a Dob with the Power Switch for Binos, 2" nose, Middle Newt Spacer, and optional OCS A-45 weighs in at 32.4 oz. Add a pair of D21s for an additional 15.4 oz. Add The Filter Switch for an additional 8.7 oz.

Binotron 27 Super           System

Binotron 27 Super             System


Binotron 27 SCT Super                  System

S2 Power Switch Star           Diagonal

  Binotron 27 Ala Carte

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