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• Free shipping in the contiguous United States. No surprise fees. The price you see is the price you pay.
• Unbeatable 30-Day return policy. WE pay for the return shipping AND any restocking fee enforced by the supplier so you can shop worry free.
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• Product Passion. To us, you are not simply a customer. You are a colleague who has a similar fascination for the stars and wants the best tools available to admire them. That's why we only stock products that will exceed your expectations.
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Features

• High quality Explore Scientific O-III filter
• Let only the oxygen emission lines "through"
• Absorbs all other emission lines
• Absorbs almost all of the artificial light
• Passband bandwidth: 6.5 nm
• Narrow-band design for difficult city conditions
• More contrast and details for all urban observers and astrophotographers
• An individual test report of this premium filter is included in the scope of delivery

Description

In addition to the turbulence in the air, the brightening of the night sky is the greatest obstacle to observing faint objects beyond the solar system. Street lights and other artificial lighting mean that the sky in human settlements is no longer properly black. As a result, the contrast and thus the perception of the deep-sky objects also suffer. Depending on the type of celestial object, however, part of the interfering light can be filtered out, making it easier to observe the objects.

The Explore Scientific O-III filter uses the property of the so-called emission mist. These objects glow in certain colors, the so-called emission lines. The emission lines are linked to certain chemical elements - in this case, oxygen. The Explore Scientific O-III nebula filter blocks all other colors (and thus almost all artificial light) and only allows the two emission lines of oxygen by. The effect is amazing: Suddenly, fog becomes visible in places that appear completely empty without a filter. In a slightly brightened sky, for example, the Cirrus Nebula NGC 6992 is practically invisible with a 200 mm telescope. When using this filter, you can see the fog and its structures without any problems. A must for every amateur visual astronomer and also for astrophotography.

The Explore Scientific mist filters are supplied with an individual test report - so you can be sure that you are receiving high-quality filters.

The narrow pass range of this filter of only 6.5 nm bandwidth works out the weakly glowing emission nebulae even under difficult city conditions or makes them visible in the first place.

Eyepiece holder plug diameter:50.8 mm

CA Residents: Prop 65 WARNING(S)

• We are happy to offer free shipping to all bordering states in the United States
• Shipping typically takes 2-5 business days and is sent directly from the manufacturer
• A tracking number will be provided when the manufacturer ships out the items. Please allow up to 5 business days to be provided with a tracking number

30-Day Return Policy: no postage, no restocking fee, no worries!

Astraeus Optics will cover shipping fees as well as any restocking fee that the manufacturer enforces.

To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging. Custom made items are not eligible for returns or refunds.

There are certain situations where only partial refunds are granted: (if applicable)

• Any item not in its original condition, is damaged or missing parts for reasons not due to our error.
• Any item that is returned more than 30 days after delivery

You can request a refund by Contacting Us.
We will credit you for the total purchase price upon the receipt of your return. Products returned under this policy are eligible for a refund to the original method of payment.

Defective Product Returns

We only replace items if they are defective or damaged. If you need to exchange it for the same item, send us an email at support@astraeusoptics.com

Refunds

We will notify you once we’ve received and inspected your return, and let you know if the refund was approved or not. If approved, you’ll be automatically refunded on your original payment method within 10 business days. Please remember it can take some time for your bank or credit card company to process and post the refund too.
If more than 15 business days have passed since we’ve approved your return, please contact us at support@astraeusoptics.com