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Explore Scientific

Explore Scientific S-II 7nm Narrowband Filter 2" — Ultra-Narrow Sulfur-II Filter for Wide-Field Imaging

Explore Scientific S-II 7nm Narrowband Filter 2" — Ultra-Narrow Sulfur-II Filter for Wide-Field Imaging

Regular price $215.00
Regular price $299.99 Sale price $215.00
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The Explore Scientific S-II 7nm Narrowband Filter (2") isolates the deep-red light of doubly-ionized sulfur (S-II, ~672nm) with a tight 7nm passband, for maximum-contrast narrowband astrophotography on 2" filter systems. The narrower bandwidth blocks even more light pollution and skyglow, revealing faint emission-nebula structure against a very dark background.

Who it's for

Astrophotographers using monochrome cameras with 2" filter wheels or drawers — especially under light-polluted skies — who want the highest contrast on emission nebulae. New to filters? See our guide to the best telescope filters for beginners.

Key features

  • Isolates the S-II line (~672nm) with a tight 7nm passband
  • Higher contrast and excellent light-pollution and moonlight rejection
  • Reveals faint nebula detail for deep, structured images
  • 2" format for full-frame sensors and large imaging trains
  • Part of the S-II / H-Alpha / O-III set for Hubble-palette (SHO) images

Specifications

Type Narrowband S-II imaging filter
Emission line S-II (~672 nm)
Bandwidth 7 nm
Fitting 2" threaded
SKU 310120

Frequently asked questions

7nm or 12nm?
7nm gives higher contrast and better light-pollution rejection, best with slower focal ratios; 12nm is more forgiving with fast telescopes. Both isolate the same S-II line.

What camera do I need?
Narrowband filters are designed for monochrome astronomy cameras, combining S-II, H-Alpha, and O-III frames into a color image.

Why 2"?
2" filters prevent vignetting with larger sensors and imaging trains; choose 1.25" for smaller cameras and filter wheels.

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Frequently Asked Questions

With a beginner telescope you can see a surprising amount — the craters and mountains on the Moon, the rings of Saturn, the moons of Jupiter, and star clusters like the Pleiades. As you get more comfortable, you can also spot nebulae and distant galaxies. Not sure which beginner telescope is right for you? Check out our Telescope Buying Guide.
Orders are usually processed within 1–2 business days, and standard delivery takes 4–8 business days after that. You'll receive a shipping confirmation email with your tracking number as soon as your order ships. Free standard shipping applies to the 48 contiguous US states. For full details, visit our Shipping Policy.
You have 30 days from delivery to request a return. Items must be unused, unassembled, and in their original packaging with all accessories. To start a return, email info@telescopewolves.com with your order number — returns sent without approval can't be accepted. For change-of-mind returns, you cover return shipping and a 5% restocking fee applies. Refunds go back to your original payment method. See our full Refund Policy for details.
Yes! If you find a lower advertised price on an identical, new, in-stock item from an authorized online retailer within one month of your purchase, we'll refund you the difference (item price plus shipping, excluding taxes). Just email info@telescopewolves.com with your order number and a link or screenshot of the lower price. Learn more on our Price Match Guarantee page.
All telescopes on Telescope Wolves are hand-picked with beginners in mind. If you're unsure which telescope is right for you, check out our Telescope Buying Guide.
Please inspect your order as soon as it arrives. If anything is damaged, defective, or incorrect, email info@telescopewolves.com within 48 hours of delivery with your order number, a short description, and photos of the item, and we'll arrange a replacement or refund.
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