Baader Narrowband-/Highspeed Filter Selector

Schritt 1

Step 1 – Select your optimal narrowband filter according to the criteria below:

Filter Wavelength

H-alpha

O-III

S-II

Average working temperature

-30° C to -10° C

-10° C to +10° C

+10° C to +30° C

Halfbandwidth (FWHM)

6.5nm Narrowband / Highspeed

3.5nm/4nm Ultra-Narrowband / Ultra-Highspeed

Depending on Sky Quality. Ultra-Narrowband/Highspeed Filters with 3.5nm/4nm are only recommend for areas with high light pollution (Bortle 9/8/7/[6] Sky).

ABSENDEN

TEXT CTA

Please make a selection above to narrow down/select the graph you need

SCHRITT 2: TEXT BILDAUSWAHL X/Y

Step 2 – Determine filter category based on aperture ratio and central obstruction:

Now determine the appropriate filter category in the graph below using the focal ratio (x-axis) and the central obstruction (y-axis) of your telescope. In the near future, we will again enable you to conveniently enter your telescope data here. The legend with links to the respective categories can be found below the graph.

All Wavelengths

H-alpha

H-alpha -20°C

H-alpha 0°C

H-alpha +20°C

O-III

O-III -20°C

O-III 0°C

O-III +20°C

S-II

S-II -20°C

S-II 0°C

S-II +20°C

NB H-alpha -20°C

Baader H-alpha 6.5nm Narrowband/Highspeed Filter @ T = -20°C

NB H-alpha 0°C

Baader H-alpha 6.5nm Narrowband/Highspeed Filter @ T = 0°C

NB H-alpha 20°C

NB OIII -20°C

NB OIII 0°C

NB OIII 20°C

NB SII -20°C

NB SII 0°C

NB SII 20°C

UNB H-alpha -20°C

Baader H-alpha 3.5nm Ultra-Narrowband/Highspeed Filter @ T = -20°C

UNB H-alpha 0°C

Baader H-alpha 3.5nm Ultra-Narrowband/Highspeed Filter @ T = 0°C

UNB H-alpha 20°C

UNB OIII -20°C

UNB OIII 0°C

UNB OIII 20°C

UNB SII -20°C

UNB SII 0°C

UNB SII 20°C

Your Telescope

f/ratio

Focal length (mm)

Aperture (mm)

f/ratio (calculated)

HTML Block

Please enter either your f/ratio (only numbers e.g. 2.2 without "f/") OR enter your Aperture and Focal Length to automatically calculate your f/ratio.

Central Obstruction (%)

Obstruction (mm)

Aperture (mm)

CAO (calculated)

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Please enter either your Central Obstrucions in % (only numbers e.g. "45" without "%") OR enter your Obstuction Diameter and Aperture Diameter (without "mm") to automatically calculate your Central Obstruction.

SCHRITT 3

Step 3 – Select filter category based on your entries:

NB-Block

Our 6.5nm Narrowband/Highspeed Filters are less critical due to their wider halfbandwidth, and therefore continue to be divided into only two categories, as before. Please select the correct color from the graphic above to determine your required filter family:

6.5nm Narrowband Filters, CMOS-optimized – for aperture ratios > f/3.4
6.5 nm f/2 Highspeed Filters, CMOS-optimized – for aperture ratios ≤ f/3.4

UNB-Block

Baader Planetarium offers three categories of 3.5nm/4nm Ultra-Narrowband/Highspeed filters with different pre-shift to the respective central wavelength. Please select the correct color from the graphic above to determine your required filter family:

3,5 / 4 nm Ultra-Narrowband Filters, CMOS-optimized – for aperture ratios > f/3.4
3,5 / 4 nm f/3 Ultra-Highspeed Filters, CMOS-optimized – for aperture ratios f/3.4 bis f/2.3
3,5 / 4 nm f/2 Ultra-Highspeed Filter, CMOS-optimized – for aperture ratios < f/2.3

Service & Company

Service & Company