Antlia ALP-T Dual Narrowband 3nm Ha&OIII /3.5nm Hb&SII 2 Filter Set for f/4 & Slower Telescopes - 2" Mounted

Product Details

1. Antlia ALP-T Dualband 3nm Ha&OIII Filter

The Antlia ALP-T Dualband 3nm Ha&OIII Filter is a dual narrowband filter, which lets the red H-alpha (656.3nm) and the blue-green OIII (500.7nm) lines through and is primarily engineered for color cameras to assist astrophotographers taking deep sky images with superior SNR(Signal to Noise Ratio). With an FWHM half-bandwidth designed at 3nm and achieving an optical density (OD) of 4.5 on unwanted wavelengths, it works strongly in blocking light pollution, moonlight, and airglow, leading to enhanced contrast in nebulae images by effectively passing the Ha and OIII emission lines signal only.

Of note, Antlia has the 3.5nm dual band SII&H-beta version available.

The combination of these two dual band Ha&OIII and SII&H-beta filters allows extreme narrow-band images with OSC cameras by capturing the spectral data from 4 channels i.e. Ha/OIII/SII/Hb. The spectrum of these four channels can be separated and recombined into various color palettes in your post-processing. The resulting images can be used for luminance contrast enhancement of traditional RGB-balanced images or the creation of images in various popular false-color palettes such as H-O-Hb, S-H-O, H-S-OHb, H-O-O, etc.

The advanced multi-coatings on Antlia ALP-T dual-band filters effectively isolate the red, Ha line, blue-green, OIII line, deep red SII, and the blue H-beta lines from emission nebulae, with almost total suppression of optical density (OD)4.5 on unwanted wavelengths from light pollution, moonlight, and airglow. The result is that both the ALP-T dual band Ha&OIII version and SII&Hb version create a superior signal-to-noise ratio and better contrast in your OSC images whether used in urban or rural areas, making them excellent choices for astrophotographers aiming to capture high-quality and more detailed celestial images.

When you buy 2 filters of the Ha&OIII version and the SII&H-beta version as a COMBO, you can get them at a cheaper price.

The main features and application

Passes OIII 500.7nm and H-alpha 656.3nm lines

Capturing of the two main emission wavebands in the red and blue-green at the same time

Ultra FWHM 3nm design allows for increasing exposure time and capturing detailed nebulae signal Designed to be used primarily with color cameras to capture cleaner data or used as Luminance filter mono cameras to save imaging time

Recommended to be used with ALP-T Dual Band SII&Hb filter to create images with better

SNR( signal-to-noise) and better isolation between the 4 channels

Suppression of optical density (OD)4.5 on unwanted wavelengths adds signal-to-noise

Near IR (NIR) is blocked up to 1100nm

deal flat-top and moderate bandpass reducing spectrum downshifts

Recommended to use the filter with optics f-ratios slower than f/4 for best performance, for optics faster than f/4, pre-shifted highspeed version is a better choice
Ion Gun Assisted Deposition of double-sided multi-layer coating technology on the double-sided polished substrate making it the most consistent and accurate light pollution suppression filter

Halo suppression anti-reflective coating is used to minimize halo and internal reflections

Designed to suppress artificial lighting from Bortle scale 1 to Bortle scale 8

Blackened edges of unmounted sizes to minimize internal reflections
Antlia's ever-trusted coating technology makes its durability very reliable
While primarily designed for use with color cameras, the filter is also highly effective with monochrome cameras to save imaging time

2. Antlia ALP-T dualband 3.5nm SII&H-beta Filter

The ALP-T dual band 3.5nm SII&Hb filter is a dual narrowband filter, which lets the deep red Sulfur-II 672.4nm and the blue Hydrogen-Beta 486.1nm lines through and is primarily engineered for color cameras to assist astrophotographers taking deep sky images with superior SNR(Signal to Noise Ratio). With an FWHM half-bandwidth designed at 3.5nm and achieving an optical density (OD) of 4.5 on unwanted wavelengths, it works strongly in blocking light pollution, moonlight, and airglow, leading to enhanced contrast in nebulae images by effectively passing the SII and H-beta emission lines signal only.

It is a significant addition to the popular Antlia ALP-T dual-band Ha&OIII filter and enables false-color images and narrow-band nebula images using OSC. When capturing data with this filter, the nebulae are recorded with high signal-to-noise ratios and greater contrast than without it.

The combination of these two dual band Ha&OIII and SII&H-beta filters allows extreme narrow-band images with OSC cameras by capturing the spectral data from 4 channels i.e. Ha/OIII/SII/Hb. The spectrum of these four channels can be separated and recombined into various color palettes in your post-processing. The resulting images can be used for luminance contrast enhancement of traditional RGB-balanced images or the creation of images in various popular false-color palettes such as H-O-Hb, S-H-O, H-S-OHb, H-O-O, etc.

The advanced multi-coatings on Antlia ALP-T dual-band filters effectively isolate the red, Ha line, blue-green, OIII line, deep red SII, and the blue H-beta lines from emission nebulae, with almost total suppression of optical density (OD)4.5 on unwanted wavelengths from light pollution, moonlight, and airglow. The result is that both the ALP-T dual band Ha&OIII version and SII&Hb version create a superior signal-to-noise ratio and better contrast in your OSC images whether used in urban or rural areas, making them excellent choices for astrophotographers aiming to capture high-quality and more detailed celestial images.

When you buy 2 filters of the Ha&OIII version and the SII&H-beta version as a COMBO, you can get them at a cheaper price.

The main features and application

Passes SII 672.4nm and H-Beta 486.1nm lines

Capturing of the two main emission wavebands in the deep red and blue at the same time

Ultra FWHM 3.5nm design allows for increasing exposure time and capturing detailed nebulae signal

Designed to be used primarily with color cameras to capture cleaner data or used as Luminance filter mono cameras to save imaging time
Recommended to be used with ALP-T Dual Band Ha&OIII filter to create images with better
SNR( signal-to-noise) and better isolation between the 4 channels

Suppression of optical density (OD)4.5 on unwanted wavelengths improves SNR( signal-to-noise) Near IR (NIR) is blocked up to 1100nm
Ideal flat-top and moderate bandpass reducing spectrum downshifts

Recommended to use the filter with optics f-ratios slower than f/4 for best performance, for optics faster than f/4, pre-shifted highspeed version is a better choice

Ion Gun Assisted Deposition of double-sided multi-layer coating technology on the double-sided polished substrate making it the most consistent and accurate light pollution suppression filter

Halo suppression anti-reflective coating is used to minimize halo and internal reflections
Designed to suppress artificial lighting from Bortle scale 1 to Bortle scale 8

Blackened edges of unmounted sizes to minimize internal reflections
Antlia's ever-trusted coating technology makes filter durability very reliable
While primarily designed for use with color cameras, the filter is also highly effective with monochrome cameras to save imaging time

Why design SII&Hb bands pass instead of OIII&SII bands?

The filter is dedicated to capture H-beta and SII emission lines. We know that SII is singly ionized sulfur that emits light in the deep red part of the spectrum, beyond H-alpha, but the contribution of H-beta to emission lines in nebulae is frequently overlooked, even though it is the second most common Hydrogen emission after the H-alpha line. Capturing more OIII will boost the existing signal but does not give more information. However H-beta has the potential to reveal structures not seen using OIII. The design is to capture the H-beta emission line in the certain nebulas that contain some blue spectrum, this cannot be captured by H-alpha, SII and OIII filters. Greater and richer details will be captured in many nebulae images to achieve results with a superior signal-to-noise ratio.

It is generally accepted that the OIII signal is a relatively weaker contributor to nebulae images. The OIII bandpass sensitivity is an important consideration for any nebulae filter. Most colour cameras (OSC) use a RGGB Bayer pattern. The allocation of twice as many green pixels as compared to either red or blue pixels, enables a much-improved capture of the OIII signal. Furthermore, higher OIII signal can be achieved by additional exposure using the Antlia ALP-T Ha&OIII filter, then isolating the GB channels, followed by synthesis of an OIII channel to add into your stack.

In the situation where you may only want to add SII to your Ha&OIII data, then it may be preferable to buy one SII narrowband filter and achieve a cleaner SII spectral emission. However, our new filter design (SII&Hb) includes the H-beta emission line which provides a distinct improvement in nebulae contrast and improved feature separation in H-beta areas.

Antlia ALP-T Dual Band Ha&OIII filter: Dual band filter with a very narrow passband in OIII and H-alpha to achieve a higher signal-to-noise ratio. The resulting contrast improvement for OSC is impressive.

Antlia ALP-T Dual Band SII&Hb filter: Dual band filter with a very narrow passband in H-beta and S-II. This filter is ideal for increasing contrast of nebulae that emit in the sulfur and H-beta range using OSC. It provides additional feature separation and isolation in Hb areas.

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
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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.