---
product_id: 12559679
title: "Semi-APO Filter 2\" FSAPO-2"
brand: "baader planetarium"
price: "2859 kr"
currency: DKK
in_stock: true
reviews_count: 5
category: "Baader Planetarium"
url: https://www.desertcart.dk/products/12559679-semi-apo-filter-2-fsapo-2
store_origin: DK
region: Denmark
---

# Strong violet fringe reduction Enhanced Mars & Jupiter contrast Zero image degradation tech Semi-APO Filter 2" FSAPO-2

**Brand:** baader planetarium
**Price:** 2859 kr
**Availability:** ✅ In Stock

## Summary

> 🪐 See Mars Like Never Before — The Semi-APO Filter That’s Out of This World!

## Quick Answers

- **What is this?** Semi-APO Filter 2" FSAPO-2 by baader planetarium
- **How much does it cost?** 2859 kr with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.dk](https://www.desertcart.dk/products/12559679-semi-apo-filter-2-fsapo-2)

## Best For

- baader planetarium enthusiasts

## Why This Product

- Trusted baader planetarium brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Cut the Violet Noise:** Advanced Fringe Killer coating slashes annoying violet fringing for crystal-clear views.
- • **Invisible Performance:** Ultra-neutral coloration ensures the filter practically disappears in your optical path.
- • **Universal Compatibility:** Optimized for achromats, SCTs, Dobsonians, and apochromats—your all-in-one planetary filter.
- • **Mars-Ready Contrast Boost:** Neodymium substrate amplifies RGB contrast, making Martian details pop like never before.
- • **Precision Polish, No Compromise:** Optically polished surfaces maintain razor-sharp images without dimming your field excessively.

## Overview

The Baader Planetarium Semi-APO Filter 2" FSAPO-2 uniquely combines Baader’s Fringe Killer coating with a Neodymium substrate to drastically reduce violet fringing and boost RGB contrast, especially enhancing planetary views of Mars and Jupiter. Designed for achromats and other telescopes, it delivers zero image degradation with ultra-neutral coloration, making it a must-have for serious amateur astronomers seeking sharper, more vivid celestial observations.

## Description

Baader Planetarium Semi APO Filter 2"The Baader Semi APO filter is a truly innovative product unique to Baader Planetarium. Founded by combining properties from two of their most popular filters the Baader Planetarium Semi APO Filter is a truly effective tool in fighting false color.Baader's newest addition for Achromat owners. The Semi-APO works like it's name implies - delivering an amazingly neutral view, while cutting most of the annoying and contrast-robbing violet fringe that plagues all achromats. The Semi-APO filter combines a stronger Fringe Killer coating formula with the Moon&Skyglow Neodymium substrate. The result is similar performance to the Fringe Killer + Moon&Skyglow combination, but with a slightly stronger violet cut - and at an even greater value.The Semi-APO filter benefits from all the host of world-class Baader filter attributes. The Semi-APO filter is truly the world's most advanced 'minus-violet' type filter in every regard. It's high efficiency and neutral coloration make it practically disappear in use - while making most of the violet fringe disappear! The effects on sharpness, contrast, and aesthetics are remarkable, even with small refractors. The RGB enhancement of the Neodymium substrate actually boosts color contrasts, particularly for Jupiter and Mars.As a side benefit, the Semi-APO filter has also proven to be the best Mars filter we've used - with ALL Telescopes, including large Dobsonians, SCTs, and Apochromats. The unique properties that result from the combination of the Fringe Killer's blue wavelength attenuation (attenuation - not total elimination), plus the selective Neodymium RGB passbands, result in a significant contrast enhancement of Martian features. The image retains its natural coloration and brightness, and the optically polished surfaces maintain every bit of the image sharpness, unlike other manufacturer's filters.&

Review: 9 doublet by explore scientific in hopes of making the scope work better for photography - This filter may work for long tube F8 or higher refractors. I bought one for e my AR102 F6.9 doublet by explore scientific in hopes of making the scope work better for photography. On this scope the filter did little to the overblown blue glow around stars on long exposures. I tried shots of nebula and had the same issues with all the stars around the shot. While it did cut the blue glow some. this is not a fix for a short tube refractor. Tried it on my Celestron d70 I bought for a guide scope and solar scope. It did not work on that scope either.
Review: Five Stars - Great filter, beaware it dims your field as well

## Features

- Baader Planetarium Semi APO Filter combines the Baader Fringe Killer coating formula with the Baade
- Zero image degradation
- Famous Baader Quality
- Works as a great Mars filter

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0018IWQC8 |
| Best Sellers Rank | #355 in Telescope Filters |
| Brand | Baader Planetarium |
| Bullet Point | Baader Planetarium Semi APO Filter combines the Baader Fringe Killer coating formula with the Baade, Famous Baader Quality, Works as a great Mars filter, Zero image degradation |
| Coating Description | No Coating |
| Customer Reviews | 2.7 2.7 out of 5 stars (5) |
| Enclosure Material | neodymium |
| Global Trade Identification Number | 04047825009333 |
| Item Dimensions | 2.95 x 2.95 x 0.79 inches |
| Item Dimensions L x W | 2"L x 2"W |
| Item Volume | 0.02 Fluid Ounces |
| Item Weight | 66 Grams |
| List Price | 190.0 |
| Manufacturer | Baader Planetarium |
| Manufacturer Part Number | 2458399 |
| Model Number | 2458399 |
| Model Year | 2014 |
| Package Quantity | 1 |
| Package Weight | 3.53 ounces |
| Size | 1.25 Inch Semi-APO Filter,2 Inch Semi-APO Filter |
| Special Effect | Ultraviolet |
| Thread Size | 2 Inches |
| Title | Baader Planetarium Semi-APO Filter 2" FSAPO-2 |
| UPC | 962392003895 |
| Water Resistance Level | Not Water Resistant |

## Product Details

- **Brand:** Baader Planetarium
- **Coating Description:** No Coating
- **Global Trade Identification Number:** 04047825009333
- **Material:** neodymium
- **Photo Filter Effect Type:** Ultraviolet
- **Photo Filter Thread Size:** 2 Inches
- **Product Dimensions:** 2"L x 2"W
- **UPC:** 962392003895
- **Water Resistance Level:** Not Water Resistant

## Images

![Semi-APO Filter 2" FSAPO-2 - Image 1](https://m.media-amazon.com/images/I/71w81XvpdhL.jpg)
![Semi-APO Filter 2" FSAPO-2 - Image 2](https://m.media-amazon.com/images/I/81PraLrWMpL.jpg)
![Semi-APO Filter 2" FSAPO-2 - Image 3](https://m.media-amazon.com/images/I/61Cs0GCwimL.jpg)
![Semi-APO Filter 2" FSAPO-2 - Image 4](https://m.media-amazon.com/images/I/919cJmbPPgL.jpg)

## Customer Reviews

### ⭐ 9 doublet by explore scientific in hopes of making the scope work better for photography
*by A***R on September 14, 2016*

This filter may work for long tube F8 or higher refractors. I bought one for e my AR102 F6.9 doublet by explore scientific in hopes of making the scope work better for photography. On this scope the filter did little to the overblown blue glow around stars on long exposures. I tried shots of nebula and had the same issues with all the stars around the shot. While it did cut the blue glow some. this is not a fix for a short tube refractor. Tried it on my Celestron d70 I bought for a guide scope and solar scope. It did not work on that scope either.

### ⭐⭐⭐⭐⭐ Five Stars
*by J***S on July 20, 2015*

Great filter, beaware it dims your field as well

### ⭐⭐ Not Worth It
*by M***D on January 12, 2013*

I bought this filter to use with my 6" achromatic refractor after reading other reviews around the net stating that it reduced chromatic aberration (CA) without affecting natural color like some other filters. I've tried the filter several times while viewing Jupiter, and it does cut down a lot of the CA, but does this at the expenses of dimming the object too much at higher magnifications. I found that I liked the views of Jupiter with CA better than the views with the filter. I also felt that I was seeing more detail on the planet without the filter and that the filter caused somewhat of a loss of contrast. Considering the cost of this filter I feel that the value just isn't there and I regret purchasing it.

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.dk/products/12559679-semi-apo-filter-2-fsapo-2](https://www.desertcart.dk/products/12559679-semi-apo-filter-2-fsapo-2)

---

*Product available on Desertcart Denmark*
*Store origin: DK*
*Last updated: 2026-06-22*