Antlia Methane (CH4) Filter - 1.25''

Antlia methane (CH4) filter is a specialized filter that allows light in the near infrared portion of the spectrum centered at 889nm to pass through with a bandpass that is 20nm wide. This filter was developed in order to measure finer details and more contrast of the methane that is characteristic of Jupiter, Mars, Saturn and other planets.

The human eye is not sensitive to light beyond about 700nm hence no person can see what is transmitted by this filter, so this filter is not suitable for visual applications.

The Methane (CH4) filter is recommended for planetary imaging such like Mars, Jupiter, Saturn and the other planets.

In order to produce good results, you are likely to require relatively longer exposures times and larger aperture telescope with this filter than with other filters.

Technical Data:

• optical substrate
• Thickness: 1.25” (2mm+/-0.05mm)
• Surface Quality: 60/40 (Refer to MIL-O-13830)
• 2 sides fine-optically polished to ensure accurate 1/4 wavefront
• 30 arcsec parallelism
• Center-Wavelength of Antlia CH4 filter: 889nm
• Tave＞90% , 90% transmission at 889nm
• OD5（0.001%）@ 200-1050nm
• 2 sides Multi-layers anti-reflection coating
• Single / Non-glued substrate

Filter Ring:

• 1.25”(M28.5*0.6)
• Ultra-thin filter cell to minimize vignetting by maximize possible clear aperture
• Black Anodized Finish
• Laser Engraving No Fading

Warning:

1. when attempting to image the Sun with CH4 filters note this is not for visual applications

2. If an energy rejection filter is not used in conjunction with the Methane Filter then the heat can be sufficient to damage the telescope, the Methane Filter, and the imaging system.

3. Antlia methane (CH4) filter is a specialized filter that allows light in the near infrared portion of the spectrum centered at 889nm to pass through with a bandpass that is 20nm wide. This filter was developed in order to measure finer details and more contrast of the methane that is characteristic of Jupiter, Mars, Saturn and other planets.

4. The human eye is not sensitive to light beyond about 700nm hence no person can see what is transmitted by this filter, so this filter is not suitable for visual applications.

When using monochrome (black and white) CCD cameras (like The Imaging Source, ALCCD5, etc) filters are needed to produce dcolor images.

The Astronomik LRGB 4 filter-kit was designed especially for CCD imaging, resulting in true color images, even when taking images with continuum or emission spectrum. This filter set is the best in its class.

The Astronomik Pro Planet 642, 742 and 807 or Castell IR-Pass filters are used to capture images in the near infrared light there atmospheric distortions are less evident, resulting in higher resolution when imaging planets or the Moon. Can be used with excellent results for Moon, Mars, Jupiter, Saturn and other planets.

The ZWO 1.25″ IR 850nm Pass Filter is suitable for IR sensitive cameras. You don’t need to debayer and get the full resolution of this sensor when use it with a color camera such as the ZWO ASI224MC or ASI185MC, because the QE responce  of sensor beyond 850nm is all the same (i.e. infrared light passes through the Bayer colour layer). So you can use a color camera as mono camera with this filter, just don’t forget to keep the WB_R and WB_B settings to 50 (no White Balance applied).