Are you trying to find telescope diagonals among various brands on the market but aren’t sure where to begin? To assist you in finding the right one, we’ve put together a list of the 7 best to help you pick the perfect one!
We investigated and evaluated a number of the top-selling telescope diagonals on the market in order to create our list of the best. Making a decision among the many options available is never simple. There are an infinite number of models available, each with a distinct price. And as you’ll find out, the best options aren’t usually the ones you imagine! This comparison is rich and relevant because of the numerous factors that were employed. You will find products featured in this ranking not only based on their pricing but also on their features and other customers reviews. To write this review, we completed 23 hours of research and did 95 telescope diagonals tests. You won’t need to pick products at random any more. If you’re unsure of what to look for, browse our list and consult the buying guide!
An overview of our top picks
Table of contents
The best telescope diagonals you can buy today
- Dielectric coatings; super flat mirror with dielectric coatings to reduce reflected light loss; provide an over 99% reflective surface; good for astronomical viewing
- 1.25 inches nosepiece fits 1.25 inches telescopes; accepts standard 1.25in filters; eyepieces; Barlow lenses and other accessories with a 1.25in insert barrel
- 90 degree viewing angle; diagonal reflects the telescope’s light path 90 degree to provide a more comfortable viewing angle; best for observing objects overhead
- Correct upside down and left right reversed image; the view image is upright; but left and right reversed if use the 90 degrees to your telescope
- Brass compression ring; Built in brass ring and thumbscrew accessories avoid eyepiece to rotate during adjustments; effortless fixes more firmly and will not scratch your eyepieces barrels
- Standard 1.25'' diameter;fit for 1.25'' focuser and eyepiece;work with refractor and catadioptric telescopes;not recommended for reflector telescope
- Fully coated lens come with dust cover;keep your lens clean for superior image fidelity
- Wide 90 degree angle;you can view correct image from refractor telescope stand and just look down with a comfortable angle
- 1.25" 90 degree diagonal mirror using with refrator telescope and makes the image upright;though left and right reversed;not affect astronomical observation
- Made of aluminum alloy and durable
- The 90% reflectivity flat mirror can reduce light loss and make the field of view clearer and sharper
- Standard 1.25 inches diameter can be used with 1.25 inches telescope accessories such as eyepieces and barlow lens
- 90 degree viewing angle; provide a more comfortable observation angle to observe the stars above the head
- Compatible with refractors and catadioptric telescopes; not suitable for reflector telescopes
- Body material is full metal; With dust cover always keep your lens clear prolong life
- Excellent Quality Dielectric Diagonal; Mirror Star Diagonal - 99% Reflectivity；Provides a Comfortable 90 Degree View from your Refractor; Fits Standard 2" (50.8 mm) Diameter Focus Tubes; Use Both 2" (50.8 mm) and 1.25" (31.75 mm) Eyepieces
- New 2" 90 deg 99% Dielectric Mirror Diagonal for Telescope With 1.25" adapter; full metal;has a 1/10th wave flat optical glass surface;solid aluminum housing;threaded to accept standard 2" filters;The 2" eyepiece holder uses a non-marring brass compression ring to secure your valuable eyepieces. The 1.25" adapter also has a non-marring brass compression ring
- Both sizes of eyepieces may be used and are protected from dings and scratches that would result from a standard set-screw. This 2" diagonal works with any Refractor that accepts a 2" star diagonals. It can also be used with Schmidt-Cassegrain or Maksutov-Cassegrain with an optional 2 inch visual back (See below)
- Dielectric diagonal is especially important;A standard aluminized diagonal has about 92% reflectance;And this decreases with time as the aluminum mirror surface ages
- For the vast majority of the visible spectrum;the reflectance does not vary more than about 0.1% below 100%;And the dielectric surface does not age like aluminum;This combination leads to the equivalent of a little more light grasp compared to standard diagonals
- High quality optical Prism inside rather than a mirror which makes your image clear and sharp.
- More comfortable viewing orientation as you observe from above, filter thread for any 1.25" filter. Accepts standard 1.25" eyepieces.
- Protective coating on the mirror to ensure a long life, metal barrel - for secure seating in the focuser.
- This is a great diagonal for daytime terrestrial use and night time astronomy applications for telescopes or spotting scopes.
- 1.25" 45-degree mirror star diagonal for refractor telescopes with 1.25" connector (not recommended for reflectors).
- 2” SCT mirror diagonal with high performance XLT coatings
- 1/10th wave mirror is tested with an interferometer to ensure quality
- Housing is precision machined to achieve and hold good optical alignment.
- Includes a 2” to 1.25” adapter and aluminum carry case
- Enhanced Aluminum Die; the SV221 diagonal mirror is designed with enhanced aluminum mold; which has higher light transmittance and clearer vision
- 1.25 inches diameter; the SV221 diagonal mirror has a diameter of 1.25 inches; which can be applied to a 1.25 inches telescope and a 1.25 inches eyepiece
- With a brass pressure ring; the SV221 diagonal mirror has a brass pressure ring; which can prevent surface damage and scratch marks when the eyepiece is used with the SV221
- Supports 1.25-inch filters features internal extinction treatment and supports the connection of 1.25-inch filters; Offering versatility for various observations
- With filter thread; the SV221 diagonal mirror has M28.5x0.6mm filter thread; which supports the connection of 1.25 inches filter
- 90 degrees design; the SV221 diagonal mirror 90 degrees deflection angle design; you don't have to bend over when performing visual observation; and the observation experience is more comfortable
- Internal extinction design; the SV221 diagonal mirror has internal extinction treatment; and the acquired image is clearer and brighter
- 【Fit for 1.25" Eyepieces】 Compatible with all 1.25" eyepieces and telescope focusers
- 【Work with Refractor Telescopes】 This diagonal telescope mirror is only suitable for refractor and catadioptric telescopes, not recommended for reflector telescopes
- 【Achieve Optimal Positions】 When the diagonal mirror is installed on the vertical axis, you will see an upright image with a mirroring effect (left to right reversal). When installed on the horizontal axis, the image will appear in an upside down orientation. No matter how you install the diagonal mirror, you will get an optimal position for observing landscapes, wildlife, and astronomy
- 【Secure & Safe Installation】 Directly insert the silver end into a 1.25" telescope and fasten the telescope eyepiece with the screw knob. The copper ring offers great securing strength and keeps the eyepiece in pristine condition free from scratches
- 【Impeccable Image Quality】 The diagonal mirror is made of quality optical glass with coatings for crisp and sharp images as well as high color fidelity. The durable construction is suitable for outdoor use
- 1.25" 90-degree mirror star diagonal for any telescope with 1.25" connector (not suitable for Newtonians).
- More comfortable viewing orientation as you observe from above, filter thread for any 1.25" filter. Accepts standard 1.25" eyepieces.
- Protective coating on the mirror to ensure a long life, metal barrel - for secure seating in the focuser.
- Useful for refractor and Cassegrain telescopes - not recommended for reflectors.
- Wide 90 degree angle: You can view correct image from refractor telescope stand and just look down with a comfortable angle.
- Enjoy better views through your telescope with this premium diagonal featuring diffraction-limited optics and dielectric coatings
- Provides a 90° viewing angle, perfect for more comfortable viewing through refractor and cass grain-type telescopes
- 58 layers of dielectric coatings provide an over 99% reflective surface, ensuring the maximum amount of light collected by the telescope reaches the eyepiece
- Twist-lock keeps the eyepiece centered in the diagonal to provide better optical alignment
- Includes a Stepdown adapter, so the diagonal accepts eyepieces, Barlow lenses, threaded filters, and other accessories in both 2” and 1. 25” sizes
- The precision flat mirror in this 90 degrees diagonal is meticulously polished to yield excellent performance
- Anodized aluminum housings are internally blackened for high contrast views free of glare
- Fits 1.25" telescope focusers, accepts 1.25" eyepieces
- Enhanced Aluminum mirror coatings yield 97% reflectivity for bright clear views
- Includes dustcaps for storage
- Achieve a comfortable viewing angle with the 90-degree diagonal mirror designed for refractor and catadioptric telescopes.
- Get clear and sharp images with fully coated lenses that come with a dust cover to keep them clean.
- Insert and use easily with the 1.25in diameter that fits most telescope focuser and eyepieces.
- Made of durable aluminum alloy, ensuring its longevity and protecting your investment.
- Designed for refractor and catadioptric telescopes to achieve an upright, but reversed left and right image. Not recommended for reflector telescopes.
- High quality optical Prism inside rather than a mirror which makes your image clear and sharp.
- 1.25" 45-degree mirror star diagonal for any telescope with 1.25" connector (not suitable for Newtonians).
- More comfortable viewing orientation as you observe from above, filter thread for any 1.25" filter. Accepts standard 1.25" eyepieces.
- This is a great diagonal for daytime terrestrial use and night time astronomy applications for telescopes or spotting scopes.
- Protective coating on the mirror to ensure a long life, metal barrel - for secure seating in the focuser.
- Image erecting BAK4 prism with anti-reflection coating.
- High accuracy and high light reflection prism.
- Internally matte blackened and threaded for no internal stray light reflection.
- 1.25" adapter with brass compression ring included.
- Entirely aluminum, black anodized, smooth finish. If there is any problem of focusing due to the light path for a few telescopes, please feel free to contact us for help.
- Wide 90 degree angle: You can view correct image from refractor telescope stand and just look down with a comfortable angle.
- Protective coating on the mirror to ensure a long life, metal barrel - for secure seating in the focuser.
- More comfortable viewing orientation as you observe from above, filter thread for any 1.25" filter. Accepts standard 1.25" eyepieces.
- Useful for refractor and Cassegrain telescopes - not recommended for reflectors.
- 1.25" 90-degree mirror star diagonal for any telescope with 1.25" connector (not suitable for Newtonians).
- - [90 Degree Angle] 90 Degree Diagonal Telescope Mirror that you can view correct image from refractor telescope stand and just look down with a comfortable angle.
- - [for 0.965 Inch Zenith Mirror] Standard inch diameter fits 0.965 eyepieces and telescope focusers. Designed for refracting and catadioptric telescopes, not for reflecting telescopes.
- - [Easy to Use] 90 degree diagonal mirror using with refrator telescope and makes the image upright;though left and right reversed;not affect astronomical observation.
- - [Easy to Install] The telescope refractors is easy to install and use. The silver end is inserted into the 0.965 telescope, and the other end is screwed to fix the 0.965 eyepiece.
- - [After-sales] We are committed to bringing customers a good shopping experience. If you have any questions about the Telescope Refractor, you can contact our customer service, and we will do our best to solve the problem for you.
- 2" Diagonal Mirror with 99% reflection, optics are made with Pyrex glass.
- Multi-layered dielectric coatings that produce 99-percent reflectivity for brighter, sharper images.
- Comes with dielectric coatings for the most light transmission possible.
- Suitable for refractors, Schmidt-Cassegrains, ACF, EdgeHD and Maksutov-Cassegrains.
- 2" - 1.25" reducing sleeve with brass compression ring, non-marring compression safety secures the eyepieces.
- We don't know when or if this item will be back in stock.
- It fits all rear cells of Schmidt-Cassegrain telescopes equipped with a big, 2" focuser and can use with refractor telescopes with SCT adapter which you can find in our store(NOT INCLUDE).
- The 2" diagonal features dielectric coatings with 93% reflectivity across the visible spectrum and a 1/10 wave mirror for bright and true images.
- Allows you to take advantage of the wider field of view provided by two inch eyepieces. Dielectric coatings are more durable than regular or enhanced aluminum coatings, so you will enjoy years of excellent performance from this product.
- Associated with 90°mirror diagonals, which let you view objects that are at a 90°angle from the direction the telescope is pointing.
- Improved attachment design features a brass clamping ring which does not mar, and provides a more secure connection.
- All-surface multilayer coated.
- Used for 1.25 inch focus seat and 1.25inch eyepiece.
- Interface with 1.25 inch thread can be connected with 1.25in filter.
- Constructed with aluminum alloy housing and stainless steel cover plate, available for long lifespan.
- Not recommended for use in reflective telescopes.
How to choose a good telescope diagonals
Does the idea of finding a fantastic telescope diagonals make you anxious? When it comes to purchasing this product, specifically when deciding which model to select, has your head been spinning between options? You are not alone if that is the case. We are aware of the pressure involved in the purchasing process!
Your presence here indicates that you are interested in telescope diagonals. Before choosing which product would be the best for your needs after being inundated with information, locate a reliable source with genuine selections. You can get that information from a variety of sources, including buying guides and rating websites, word-of-mouth recommendations from friends and family, online discussion forums where users can share their own experiences, product reviews that can be found all over the internet, and YouTube channels. You can only get the right product through exhaustive analysis. But you realize that’s not always simple. In order to ease your concerns, we have taken the time to develop a list of the top telescope diagonals products available right now. You might be wondering how we came up with the list. How was this buying guide developed?
First, we used our algorithms to gather as much reliable data as we could about these products. To verify all the data gathered, we used both artificial intelligence and a lot of algorithms.
Then, our experts used criteria that are recognized in the business to evaluate them according to their quality to price ratio, allowing us to choose the top telescope diagonals on the market right now!
The selection of the goods is not arbitrary. Before creating a list, we take into account a number of factors. Below are some of the criteria discussed:
Brand Value: What happens if you choose a dubious brand just because it appears to be a good deal? So the likelihood of receiving a product with a short shelf life increases. That is due to the fact that well-known brands have a reputation to uphold, while others do not. Top telescope diagonals brands strive to provide some distinctive traits that set them apart from the competition. So, hopefully one or more of the items on our list will be perfect for you.
Features: Useful features are all you need, not tons of them. We consider the important aspects and select the top telescope diagonals based on those.
Specifications: Numbers always help you measure the quality of a product in a quantitative way. We try to find products with higher specifications, but with the right balance.
Quality: A product’s quality may always be quantified with the aid of numbers. We look for goods with better standards that strike the proper balance. The best quality product that gets highly appreciated and recommended by experienced users.
Customer ratings: Would it be accurate to suggest that the telescope diagonals were used by hundreds of customers before you? Superior ratings indicate that many customers had better service.
Customer Reviews: Like ratings, provide you with accurate and reliable information about the product from genuine customers. Customer ratings are very important to all of us because they contain accurate and reliable information about the customer service we received from several hundred customers.
Seller Rank: This is very intriguing! Not only do you need a good telescope diagonals, you also need a product with rising sales that is trendy. It accomplishes two goals. First, the expanding user base proves the quality of the product. Second, given that number, producers must be able to offer greater quality and after-sales support.
Value: You get what you pay for, they say, so consider the value. Cheap isn’t always good and expensive isn’t always bad. However, that does not imply that spending a lot of money on a product that is flashy but underwhelming is a good idea. Before adding them to the list, we make an effort to evaluate how much value you can get for your money from your telescope diagonals.
Durability: Durability and reliability are closely related concepts. You will benefit from a strong and long-lasting telescope diagonals for months and years to come.
Product availability: Products come and go, and new ones replace the old ones. Most likely, a few new features and required changes were made. What use is it to use a supposedly good product if the maker no longer supports it? We make an effort to highlight products that are current and offered by one or more trustworthy sellers, if not more.
Negative Reviews: Yes, we do take that into account as well! The goods with the majority of bad reviews are filtered out and disregarded when we choose the best-rated one on the market.
These are the standards by which we selected our telescope diagonals. Do we end our process there? Hell no. The most crucial fact about us that you should be aware of is that we regularly update our website with current and pertinent information. We have one more layer of filtration since we place the greatest importance on reader satisfaction. Please let us know if any product included here is incorrect, irrelevant, subpar, or simply out of date. We always value your opinions, and we’ll work hard to make any necessary corrections to our list in response to them.
Why should you believe us?
There are now thousands of possibilities for these products on Amazon, but choosing the best one can be difficult and time-consuming. And what telescope diagonals should you purchase in 2022?
This guide is the result of more than 10 years of experience in researching, testing and writing about many topics. Each member of our team is an authority in their area. We read every article we could find online and every consumer review on every retail website for seven hours. Additionally, we discovered a ton of websites that offered helpful resources, including buying tips and thorough information on telescope diagonals.
