Optolong L-eXtreme

Formats

1.25″ Mounted
2″ Mounted (48mm thread)

Spectral Transmission

Yellow line is published transmission. Color fill is my independent verification with the filter I tested.

Physical Characteristics of 2″ Filter

Filter mount thickness: above threads: 4.92mm; including threads: 6.78mm
48mm threads with 0.75mm spacing
Minimal knurling only on top
Dual bandpass narrowband filter
Inner retaining ring does have notches for easy filter disassembly with a spanner
Width of the glass filter without the filter mount is 45.94mm

Real World Tests

Bortle 8, Stock Canon T7, 464mm f.l., f/5.4, ISO3200, 36 min. integration (6*6″). Open full-size image in new tab.

Bortle 8, Full Spectrum Modified Canon 60D, 464mm f.l., f/5.4, ISO3200, 36 min. integration (6*6″). Open full-size image in new tab.

Comparisons to No Filter

Stock Canon T7 - No filter vs. Optolong L-eXtreme

Full Spectrum Canon 60D - No filter vs. Optolong L-eXtreme

Reader Rating49 Votes

74

Pros

7nm bandpasses provide good contrast and tight stars

Excellent light pollution blocker

Cons

Faint halos on very bright stars created by filter

Not available in clip-in format

90

Purchase from:

High Point Scientific