SKU: 27103169127

Explore Scientific 99% Reflective 3" Diagonal

Sale price$265.50 Regular price$295.00
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Ships within 48 hours · Estimated delivery Aug 12 - Aug 17

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Description

Explore Scientific 99% Reflective 3" DiagonalA 3 inch dielectric coated star diagonal that reflects 99% of incoming light through a full 3 inch optical path designed for telescopes with 3 inch focusers where a standard 2 inch diagonal would vignette the light cone and clip the edges of wide field views. The first surface dielectric coating reflects virtually all incoming light, delivering the brightest and highest contrast image your telescope can produce. This is particularly important at the 3

A 3-inch dielectric-coated star diagonal that reflects 99% of incoming light through a full 3-inch optical path — designed for telescopes with 3-inch focusers where a standard 2-inch diagonal would vignette the light cone and clip the edges of wide-field views.

The first-surface dielectric coating reflects virtually all incoming light, delivering the brightest and highest-contrast image your telescope can produce. This is particularly important at the 3-inch aperture class, where the telescopes paired with this diagonal are typically fast, large-aperture refractors — instruments where every fraction of a percent of light transmission matters for deep-sky performance.

The double-taper insert barrel slides smoothly into 3-inch focusers and the wider taper section prevents the diagonal from accidentally falling free. A compression ring lock secures eyepieces without set screw marks. Includes a 2-inch adapter so you can use your existing 2-inch eyepiece collection, and dust covers to keep optics clean in storage.


Key Features
  • 99% first-surface dielectric coating for maximum brightness
  • Full 3" optical path — eliminates vignetting on large-format focusers
  • Double-taper insert barrel for secure, smooth fit
  • Compression ring eyepiece lock — no set screw marks
  • 2" adapter and dust covers included
  • Weight: 2.0 lbs (0.90 kg)

Ideal For
  • Large refractor owners — the ES ED152, FPL53-series, and other 3"-focuser telescopes need a 3" diagonal to avoid vignetting
  • Deep-sky visual observers — the full 3" light path paired with 99% dielectric reflectivity delivers the brightest possible wide-field views
  • 2" eyepiece users — included adapter means your existing eyepieces work immediately

Good to Know
  • 1.25" eyepiece adapter is sold separately
  • Designed for telescopes with a 3" focuser — will not fit standard 2" focuser drawtube
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 27103169127

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Kippi
Belleville, US
★★★★★ 4
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Reviewed in the United States on July 15, 2025
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trishatriedit
Alexandria, US
★★★★★ 5
Perfect!
Style: Original
Perfect for that carry on to a sunny place!!
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Reviewed in the United States on May 18, 2026
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Calc
Louisville, US
★★★★★ 5
Great Mineral Facial Sunscreen
Size: 1.7 Fl Oz (Pack of 1)
This is the best mineral facial sunscreen I’ve used. It comes out as a thin lotion that spreads easily. I have used two other brands and considered a brand that was expensive before trying this. I liked baby bum mineral 50 sunscreen lotion for the body and decided to give this a try. I like sun bum products. They tend to make effective products that are not too expensive. The zinc oxide mineral facial sunscreen I was using slightly irritated my skin and felt heavy like a mask after applying. It left a greasy residue on my face. This sun bum facial mineral sunscreen is non-irritating and feels very light like a chemical-based facial sunscreen. It leaves no residue on the skin. I prefer zinc oxide mineral sunscreen because it’s natural, safe and effective. Some zinc oxide mineral sunscreens put a white caste on the skin after application. The titanium dioxide and zinc oxide blended mineral sunscreens are worse due to the titanium dioxide. Titanium dioxide is a bright-white powdered substance, and I have not experienced any product with this ingredient that doesn’t appear white on the skin and cannot be blended. This sun bum zinc oxide mineral facial sunscreen has no white caste. Like another reviewer, I also hope that sun bum continues to make this facial mineral sunscreen indefinitely. It’s the best I’ve ever tried and at an excellent price point. If you like mineral sunscreens due to the health and environmental concerns with chemical-based sunscreens, try this before trying more expensive mineral facial sunscreens.
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Reviewed in the United States on May 12, 2025
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Schmutz1987
Fort Morgan, US
★★★★★ 5
Great product. No white cast
Size: 1.7 Fl Oz (Pack of 1)
This is a great everyday face sunscreen. It doesn’t leave a white cast. It’s not greasy. It leaves a nice dewy finish. Strongly recommend.
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Reviewed in the United States on April 6, 2026
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Daisy
Dallas, US
★★★★★ 5
Great sheer mineral sunscreen!
Size: 1.7 Fl Oz (Pack of 1), Size: 1.7 Fl Oz (Pack of 1)
I’ve never been a mineral sunscreen fan but I really love this one. I needed a mineral sunscreen for days where I knew I was going to be sweating or swimming because the chemical stuff would run into my eyes and burn so bad. This one doesn’t burn my eyes at all. It doesn’t leave a white cast but it is a little oily and leaves me quite shiny for about 10-15 mins until it fully dries. I don’t really mind because it works well. I would definitely recommend 👌
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Reviewed in the United States on October 14, 2025

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