- Dielectric coatings; super flat mirror with dielectric coatings to reduce reflected light loss; provide an over 99% reflective surface; good for astronomical viewing;
- The 1.25-inch nosepiece fits 1.25-inch telescopes and accepts standard 1.25-inch filters, eyepieces, Barlow lenses, and similar accessories; The 2-inch nosepiece is compatible with 2-inch telescopes and accommodates standard 2-inch filters and accessories. You can choose either 1.25inch or 2inch diagonal based on your requirements;
- 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.
Top Christmas Gift Ideas: Perfect Presents for Everyone!
Pre-sale on May 06,2025
Special offers and product promotions
SV188P 1.25inch 90 Degree Dielectric Diagonal for Refractor Telescope
Elevate your stargazing experience with the SV188P diagonal featuring dielectric coatings that provides over 99% reflectivity, significantly reducing light loss for brighter images.
1.25inch Diagonal
1.25in nosepiece fits telescopes with 1.25in focusers. Accepts standard 1.25” eyepieces, filters, Barlow lenses and other accessories with a 1.25in insert barrel.
90° Viewing Angle
For more comfortable overhead viewing through refractor and Cassegrain type telescopes.
Upright Image
Correct upside down and left right reversed image. It will look like trying to read a sign in a mirror. Suitable for space viewing, for there is NO upside down or right side up in space.
Brass Compression Ring
Brass lock Screw for eyepiece or adapter and brass Compression rings features more precision and prevent barrels or the surface of eyepieces from marring and scratching.
SV188P installed on the telescope
Great Upgrade
Arrived in excellent conditions!, i have a refractor telescope, and it is a great upgrade for my equipment!!
Best upgrade
If you have the basic diagonal that came with your telescope then get this one. Very bright image compared to the stock one. I love the over size knob on the eyepiece lock. Worked great with gloves on in winter. The compression ring was awesome as well. With those two features it makes this a great value and a good addition to your scope
Great Diagonal
Arrived well packaged. Well built diagonal, indispensable combined with my SV503 102ED
Little and perfect
EN: It's very light but still has substance. Excellent workmanship. It is decorative and fully fulfills its function. The mirror image is flawless.
I wouldn't believe it if it was even better. I recommend to everyone.
HUN: Nagyon könnyű de mégis van benne anyag. Kiváló kivitelezés. Dekorativ és funcióját maradéktalanul betölti. A tükör képe hibátlan.
Ha ennél is jobb volna nem hinném el. Mindenkinek ajánlom.
Great piece!
Perfect product with excellent features. And sustainable package, without needless papers and prospects and plastic. But please tell your customers, which adapter is needed for Cassegrain - and give the link to the product in your shop!
Bright and contrasty
I bought the 1.25 "mirror to be able to look into the zenith on my previous telescope. In contrast to a simple zenith mirror, the Svbony SV188P Dielectric Diagonal is a real win. The image is visibly brighter and the image quality at high magnification has also improved. Thanks to the ring clamp, the eyepieces remain free from scratches. Overall a very good mirror!
Diagonal dieléctrica
Buenas me gustaría saber cuál es el adaptador especial para la.diagonal dieléctrica sv188 P .
Gracias.
| Brand | SVBONY | |
| Model Number | SV188P | |
| SKU | F9171B | F9171D |
| Size | 1.25inch | 2inch |
| Optical Design | Mirror Diagonal | Mirror Diagonal |
| Coatings | Dielectric | |
| Reflectivity | dielectric 99% coating for bright images | |
| Material | Aluminum Alloy | |
| Filter Threads | M28.5*0.6 | M48x0.75 |
| M4 Set Screws | Yes | |
| Outer Connection(Lens Sided) | Barrel 1.25inch | Barrel 2inch |
| Inner Connection(Lens Sided) | Thread M28.5x0.6 | Thread M48x0.75 |
| Inner Connection(Eyepiece Sided) | Clamp 1.25inch | Clamp 2inch |
| Reflection Surface | Dielectrically Coated | |
| Image Orientation | Erect Image, Mirror Inverted | |
| Thickness of Mirror | 11mm | |
| Net Weight | 125g / 4.41oz | 463g |
- There are many 1.25" star diagonals on the market. Many of them have a mediocre mirror quality with 90% reflectivity (10% loss) and a plastic body. The 1.25" diagonal by SVBONY stands for a high-quality alternative to those cheap parts. It offers excellent image and mechanical quality. There's no vignetting over the full 1.25" field. SV188P features sophisticated, Multi-layered dielectric coatings that provide an outstanding 99% reflectivity for maximum view brightness and sharpness;
- SV188P Diagonals provides a comfortable 90-degree viewing orientation when observing the night sky through a refractor. When use the SV188P with Maksutov-Cassegrain (Mak-Cass) or Schmidt-Cassegrain telescope, you need a special adapter;
- Another advantage is the 1.25" nosepiece barrel is threaded to accept 1.25-Inch filters. Brass lock Screw and Brass Compression Rings feature more precision and prevent barrels or the surface of eyepieces from marring and scratching.
Applicable Accessories
US$ 11.99 ~ US$ 15.99
_md.jpg "SV133 Filters Wheel 1.25inch Multiple 5-Position")
We found other products you might like!
_md.jpg "SV135 Zoom Eyepiece 1.25inch 7mm to 21mm 57°-40° Field of View for Astronomical Observation")
