Methane (CH4) filter Antlia - 1.25'' Mounted

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

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

For good results, you will probably need relatively longer exposure times and a larger aperture telescope with this filter than with other filters.

Technical Data

Optical substrate

Thickness: 1.25" (2 mm+/-0.05 mm)

Surface quality: 60/40 (see MIL-O-13830)

2-sided fine optical polishing to ensure an accurate 1/4" wavefront

30 arc second parallelism

Antlia CH4 filter center wavelength: 889 nm

Tave＞90% , 90% transmission at 889nm

OD5（0.001%）@ 200-1050nm

2-sided Multilayer anti-reflection coating

Single substrate/non-glued

Filter ring

1.25"(M28.5*0.6)

Ultra-thin filter cell to minimize vignetting while maximizing the clear aperture possible

Black anodized finish

No Fading Laser Engraving

Warning

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

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

3. The 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 20nm wide bandpass. This filter was developed in order to measure finer details and more contrast of methane characteristic of Jupiter, Mars, Saturn and other planets.

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