Antlia 3nm Narrowband H-Alpha (Ha)/ Sulfur II (SII) /Oxygen III (OIII)Pro Filter - 50mm Unmounted Deep Space Photography Filter

Product Description

Antlia H-alpha Pro narrowband filter optimizes the FWHM (full width half maximum) to 3nmbandpass.As the bandwidth becomes narrower, the 3nm Pro narrowband filters enhance contrast of emission targets by lowering the unwanted background signal. AntliaH-alpha3nm Pro filtersaredesigned to deliver 88% transmission at the 656.3nm line which provides you with the maximum signal and well defined nebulae structures.

Conventional broader narrowband filters cause a heavy loss in transmission due to the strong Center Wavelength (CWL)-shift. We guarantee T>88% within 1nm range of the center bandwidth,which means that the 3nm Pro narrowband filter can guarantee high transmittance for working with both long focal ratios and fast optical systems.Blue-shift data shows that Antlia 3nm Pro filters can be used with nearly all systems as fast as f/3 with minimal loss in emission signaland meets the requirements of fast optics like Hyperstar and RASA.

The out of band blocking specification is rated OD5(0.001%) which delivers an excellentSNR(signal to noise ratio)and effective cut-off rate to minimize interference from other wavelengths.Improvedsharp cut-off astrophotography 3nm Pro filters are designed to minimize halos around bright stars.

Application and Performance:

High transmittance and smallest bandwidthto maximizecontrast

Steep spectral profile minimizes halos around bright stars

A single substrate to eliminate internal reflections  

Narrowband Objects: H-alpha Emission Nebulae, Planetary, Wolf Rayet Nebulae and Supernova Remnants

Use in light polluted areas anddark sites

Extendsimaging time when the moon is up

Antlia narrowband Pro filters can be useddownto F/3systemswith slight loss of signal

All AntliaNarrowband filters are edge blackened toeliminate internal reflectionsfrom stray light

Superior optical reliability reducespost image processing

This filter is not suited to deep sky objects that do not containH-alphaemissions.

Technical Specifications:

Basic Substrate:Schott optical substrate

Filter Thickness:   3mm+/-0.05mm for Dia50mm unmounted

FWHM (Full width at half maximum):3nm

CWL (Central Wavelength):656.3nmnm

Peak Transmission:＞88%

Blocking:> 5 OD(0.001%out of band blocking) @ 300-1000nm

Surface Quality:S/D (scratch/dig)= 60/40 (Refer to MIL-O-13830)

Transmitted Wavefront:Lambda/4 or better.

Parallelism:less than 30 arcsec

Single / Non-glued substrate

Warranty: 3-years against delamination

Not Recommended:

Solar Observing and imaging

Visual observation

DO NOT LOOK AT THE SUN WITHANTLIAFILTERS.

Serious eye damage will result if youfail to observe the warning.

When we design filters for astronomy imaging systems, we look at how they will work together with optical systems, carefully designing the blocking and band-pass parameters to achieve an optimum result. The out of band blocking rate is a very important performance index since it is designed to sharply attenuate off-band wavelengths. The result is that the AntliaH-alpha3nm Profilter delivers excellent contrast with extremely dark backgrounds whilst delivering a high transmission of theH-alphasignal. Such filters are more difficult to produce to a consistently high standard.

Each filter is individually tested and scanned to ensure that the quality meets the high-performance parameters. The end result is a filter that achieves excellent contrast but with a higher production cost. We believe the price to performance ratio compares more favorably than similar premium filters in the market.

Due to Covid impacts, current stock and ongoing supplies will remain intermittent.

H-ALPHA 250-880nm

H-ALPHA 600-700nm

H-ALPHA 654-659nm

H-ALPHA 250-880nm OD

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SII 250-880nm

SII 600-700nm

SII 670-674nm

SII 250-880nm OD

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O3  250-880nm

O3  600-700nm

O3   498-503nm

O3  250-880nm OD

1.1 How can I check the shipping cost for my order?
You can add the items you want to your shopping cart, enter your country/state/city/postal code, and then view the shipping options and costs on the cart page. Before checkout, you can choose your preferred shipping speed/method/carrier.

You can also contact us and send us the item model, quantity, and shipping requirements. We will calculate the accurate shipping cost for you and inform you accordingly.

1.2 How are free shipping items delivered?
Items marked as "Free Shipping" on the product page mean you do not need to pay any shipping fees. This usually applies to buyers from any country (except for certain special countries or regions).

For free shipping items, buyers cannot choose the shipping method. We will select the shipping method based on the destination country.
Typically, we use standard surface shipping methods such as 4PX, EMS, or local postal services.
We may also use UPS, FedEx, DHL, Aramex, etc., depending on the specific order and country. The final choice is at our discretion. Regardless of the shipping method used, we will notify you upon dispatch and provide a tracking number and tracking website.

• Standard tracking website: https://www.17track.net/en
• UPS: https://www.ups.com/
• FedEx: https://www.fedex.com/
• DHL: https://www.dhl.com/

Please note: If you return an item (excluding quality issues or incorrect items), you will be charged for all shipping costs incurred, including delivery, return, and customs fees.

1.3 What if I want to specify a shipping method for a free shipping item?
If you want to specify a particular shipping method (e.g., UPS or DHL) for a free shipping item, please contact us before placing your order. You will need to pay additional shipping fees, and we will ship via your preferred method.

1.4 What if I buy multiple items, some with free shipping and some that require shipping fees?
You can place your order as usual. You only need to pay shipping fees for the non-free shipping items.
If you want to specify a shipping method or have other special requests, please contact us.

1.5 How long does it take to ship my order?
After receiving your order, we need some time to process it.
Orders received before 5:00 PM China time will be shipped within 3 days.
Orders received after 5:00 PM China time will be shipped within 4 days.
Orders placed during Chinese public holidays may be delayed by 1–2 days (due to courier holidays).

1.6 When will I receive my package?
Delivery time varies depending on the shipping method used:

• 4PX, Postal Services, EMS, etc.: about 15–25 days
• UPS: about 7–15 days
• FedEx: about 7–10 days
• DHL: about 5–9 days

These are estimated times. Actual delivery is subject to the carrier's schedule.

If your package tracking has not been updated for a long time, please contact us.
If you haven't received your package after a long period, please contact us.
If there are any other irregularities, please contact us.

Please note:
After we ship your package, it may take 2–3 days for tracking information to become available.
Based on our experience, packages shipped to South America and Central Asia typically take longer.
Shipping around public holidays may result in delays due to carrier workload.

If delays occur, we kindly ask for your patience and understanding. We share the same desire as our customers—we hope every package is delivered quickly and safely.

If you want a faster and more secure delivery, we strongly recommend choosing UPS, FedEx, or DHL.

1.7 What does it mean when tracking shows "Label Created" but the order hasn't shipped yet?
When we provide a tracking number, your package has already left our warehouse.
However, the tracking status may show "Label Created" or "Awaiting Package" because the package is still en route to the courier's sorting facility.
Due to China's vast geography, transit between cities can span over 1,000 km, so it takes time.
It may also be undergoing export customs clearance. Your package should be delivered soon.

If your tracking status doesn’t update for a long time, please contact us.

1.8 What if my package needs special delivery instructions or other requests?
If your shipment requires an invoice to be attached, special packaging, delayed dispatch, or other requests, please contact us.
We will do our best to accommodate your needs and provide the best service possible.

1.9 About receiving the package
Whether you sign for the package personally or through a representative, it is considered as acceptance of the package, the quantity, and the included items.
To protect your rights, we strongly recommend recording a video while opening the package and verifying it against the order and packing list.

1.10 I don’t live in China. Can I have my order shipped to a Chinese address?
Yes, you can. Just place your order and provide a Chinese recipient address.
For orders shipped within China, we do not charge any shipping fees. If your item shows a shipping fee, please contact us to have the fee waived.

You are responsible for all applicable taxes and fees that may be imposed by your country or region, including but not limited to import duties, value-added tax (VAT), customs handling fees, and other similar charges.

These import duties, VAT, and customs fees are not included in our product prices or shipping charges.
We have no control over, and cannot predict, these charges or how they will be collected—whether they will be charged at the time of delivery or through other means.

Customs policies vary greatly by country. Some countries (such as Brazil, India, etc.) strictly enforce high duties and additional taxes.

It is your responsibility to check with your local customs office before purchase to determine what additional costs may apply.

Customs fees are usually charged by your local courier or postal service, often at the time of delivery or pick-up. The shipping carrier (especially UPS) may also charge brokerage or clearance fees for handling customs on your behalf. These are not unpaid shipping charges and must be fully covered by you.

If the package is returned, held, or destroyed due to the buyer’s refusal or failure to pay customs duties, any resulting costs will be borne entirely by the buyer. These costs will be deducted from your refund.

1.1 What is your return policy?
I ordered the wrong item/size, or I changed my mind—can I return it?
I received the item but decided I don’t like it—can I return it?
I received the item but found it’s not suitable for me, or I found a better option—can I return it?

In the above cases, we accept returns within 30 days of receiving the item, provided that the product is in brand new and unused condition.

• Buyers must apply for a return and send the product back to us within 30 days of receipt.
• You are responsible for all return shipping costs.
• We will deduct the original shipping cost incurred to deliver the item to you.
• We will deduct 4% for credit card or PayPal transaction fees.
• If you choose to receive a store credit instead of a refund, we will waive this 4% fee.
• If the returned item shows signs of use, a handling fee may be charged.

If the returned item is damaged, missing parts, or shows excessive wear, we reserve the right to reject the return and no refund will be issued.

1.2 Where should I send the return?
Please contact us for the correct return shipping address. (The return address may not be located in Mainland China.)
Please ensure the item is properly packaged and that the original product packaging is not damaged.

Important: Do NOT return the product to the sender’s address shown on the parcel. You must contact us first to obtain the correct return address. Unauthorized returns may be lost or undeliverable—any such loss will be fully borne by the buyer.

1.3 Can I return or exchange the item after 30 days?
For any reason, we do not accept returns or exchanges after 30 days.
30 days is considered a very reasonable and standard return period for online purchases.

1.4 What if I received a wrong or defective item?
Please contact us within 3 days of receiving the item and provide photo evidence or a clear description of the issue. We will promptly send a replacement item.

If you return the item to us:

• Please use the least expensive shipping method.
• We will reimburse part of the shipping fee from your original order as compensation.

If you’re unable to return the item or don’t know how to ship it, please contact us—we may provide a free return shipping label.

1.5 How will I receive my refund? How long does it take?
We will process the refund within 7 days of receiving your returned item.
Refunds are usually issued via the original payment method.
Processing the refund involves internal verification and approval by management, so we appreciate your understanding and patience.