More Information  · Images of Some Features

These Generation 2 filters should be parfocal for systems as fast as f/3.5, if your optical system is well color-corrected. This LRGB filter set has a reduced UV contribution in its luminance and blue filters. This reduces star bloat in systems that are not well color-corrected. This makes these LRGB filters best suited for imaging with refractors and camera lenses, which often are not particularly well-corrected in the violet end of the spectrum.

On the other hand, the clear (no near-IR blocking) filter in Astrodon CRGB (Clear, Red, Green, Blue) filter set #TB2CE50R may produce bloated stars if your optical system has poor near-IR focus, as is the case with many camera lenses. For this reason, this near-IR blocked LRGB filter set is the best choice for imaging with refractors and camera lenses; while Astrodon CRGB filter set #TB2CE50R would be better for imaging with reflectors, which are intrinsically more accurately color-corrected.

A spectral “gap” between approximately 540nm and 640nm minimizes the effect of mercury and high and low pressure sodium city light pollution, as well as several airglow emission lines due to ionized nitrogen in our atmosphere. This gap can be seen in the response curves in the feature image below.

The 50mm unmounted filters in this Astrodon E-Series LRGB filter set fit into any color filter wheel that accepts standard round unmounted 50mm filters, or into the color filter wheel integrated into SBIG Research Series cameras. Each filter is parfocal with Astrodon's high-performance narrowband (H-alpha, Oxygen III, etc.) and near-IR filters. The filters come individually wrapped in a hard plastic snap-lid storage case.

For more detailed information on Astrodon filters, click on the “Astrodon Generation 2 Filters” icon above.