Why use the Baader 685nm IR-Pass filter instead of a regular Luminance filter?
A regular Luminance filter passes the entire visible spectrum (roughly 400-700nm), making it susceptible to atmospheric turbulence (seeing). The Baader 685nm IR-Pass filter rejects these shorter, more easily scattered wavelengths, producing a much sharper, higher-contrast image that serves as a superior detail layer in an LRGB composite, especially on nights with poor seeing.
Can I see through the Baader 685nm IR-Pass filter to focus?
Barely. The filter begins transmitting at 670nm, which is at the very edge of human vision in the deep red. While you won't see much detail, a bright star or planet may be visible enough to aid in focusing, especially on a sensitive monochrome camera's live view. It is significantly easier to focus with than deeper IR-pass filters (like 742nm or 850nm) which are completely opaque.
What kind of camera works best with the Baader 685nm IR-Pass filter?
A monochrome CMOS or CCD camera is highly recommended. These cameras typically have much higher quantum efficiency in the near-infrared spectrum compared to one-shot color cameras, allowing for shorter exposures and better signal-to-noise ratio when using the Baader 685nm IR-Pass filter.
How will the Baader 685nm IR-Pass filter improve my images of Jupiter with an 8" SCT?
An 8" SCT has enough aperture to resolve fine detail on Jupiter, but this is often limited by seeing. The Baader 685nm IR-Pass filter will help stabilize the image, allowing you to capture sharper details in the cloud bands, the Great Red Spot, and smaller storms. By using it as your luminance channel, your final LRGB image of Jupiter will appear much more detailed than what you could capture with a standard UV/IR cut filter alone.
Is the Baader 685nm IR-Pass filter useful for solar imaging of sunspots?
Yes, absolutely. When used with a proper, full-aperture solar film or glass filter, the Baader 685nm IR-Pass filter acts as a powerful seeing-reduction tool for white-light solar imaging. It will increase the contrast and sharpness of sunspot umbra/penumbra details and solar granulation by minimizing atmospheric blurring.
Do I still need RGB filters if I use the Baader 685nm IR-Pass filter?
Yes. The image from the Baader 685nm IR-Pass filter is monochrome and only captures detail, not color. To create a full-color image, you must capture separate data using Red, Green, and Blue filters and then combine them with the high-resolution data from the IR-Pass filter in post-processing software.
