- 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.
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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
Best upgrade
Great Diagonal
Little and perfect
Great piece!
Bright and contrasty
Diagonal dieléctrica
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.