Parameters include focal length, reflectivity, transmittance, length, diameter tolerance, smoothness, substrate material and coating, etc. The following is a specific description of these parameters 

Focal Length: The stained glass filter itself does not have the property of focal length, because focal length is usually associated with the lens, and the filter is mainly used to filter light rather than focus. Therefore, when referring to colored glass filters, we usually do not discuss the focal length. 

Reflectivity: The reflectivity of stained glass filters varies by color and manufacturing process. In general, stained glass filters are designed to allow more specific colors (wavelengths) of light to pass through, rather than reflect. However, some specially designed stained glass filters may have certain reflective properties, but the specific reflectivity depends on the type and use of the filter 

Transmittance: The transmittance of stained glass filters is usually high, especially for the specific color (wavelength) of light which is designed to pass through. According to publicly released information, the transmittance of some stained glass filters can reach more than 85%. 

Length: The length (or size) of the stained glass filter can be customized according to customer needs. Common sizes have Φ12.5mm 50x50mm and other lengths or sizes, which are usually very small to ensure the accuracy and consistency of the filter. 

Diameter Tolerance: For circular stained glass filters, such as those with a diameter of 12.5mm, the diameter tolerance is usually +0.0-0.2mm which means that the actual diameter of the filter may not be less than the nominal diameter, but may be slightly larger, with a maximum of 0.2mm 

Smoothness: The smoothness of stained glass filters is usually high to ensure the smooth transmission of light. The common finish specification is 40-20, indicating the maximum and minimum number of scratches or blemishes allowed per square inch of area. 

Substrate Material: The base material of the stained glass filter is usually special glass, such as color glass, which adds special elements in the melting process to achieve absorption and transmission characteristics of different spectral bands. 

Coating: Although some stained glass filters may not be coated, depending on customer requirements, the filter can also be coated to enhance its performance or achieve a specific function. The type and thickness of the coating depends on the specific application needs. 

 In summary, the parameters of stained glass filters include transmittance, length (size), diameter tolerance, smoothness, substrate material and coating. These parameters together determine the performance and use of the filter. Please note that the specific parameter values may vary depending on the product model, manufacturer and manufacturing process