HPOIII 2.00" – DGM Optics™ OIII Astronomy Filter

SKU: OIII200

Description

The High Performance OIII filter makes an excellent complimentary filter to the NPB filter. The OIII’s high transmission and narrow bandwidth allows maximum enhancement and detail for a large variety of both emission and reflective nebula.

Spectral Curve

Measured spectral data for typical HPOIII filter

Specifications

This DGM Optics custom designed filter is well suited for a variety of telescopes and objects. The filter design stresses maximum optical throughput utilizing state-of-the-art optical thin-film designs and materials.

This filter is a “first surface” hard oxide thin-film and is much more durable and long lived than laminated “soft film” designs used by several famous makers. They are also much less prone to the internal reflectance problems that plague laminated filters. Laminated filters can produce a very undesirable “doubling” of stellar images often with one of the doubles being red. Contrary to popular belief, this image doubling is not due to the red sideband component that many nebula filter designs produce, but in many cases is due to laminated glass not being exactly parallel to the protective cover plate after lamination. Many laminated filters display this annoying characteristic.

The substrate is B-270 and has measured total wavefront values of .5 waves. The combination of first surface optical thin-film technology and a polished, flat substrate enables this filter to be used with high magnification, a real plus for small planetary nebula.