svbony filter with package

Svbony CLS

Formats

  • 1.25″ Mounted
  • 2″ Mounted (48mm thread)
  • Canon EOS APS-C Clip-in

Spectral Transmission

Yellow line is published transmission. Color fill is my independent verification with the filter I tested. Note: I used a Quartz Tungsten-Halogen bulb which is broad spectrum, but does not have good throughput in the blues hence I only vouch for the accuracy of my independent verification from 500-900nm.

Physical Characteristics of 2″ filter

  • Filter mount thickness: above threads: 4.94mm; including threads: 6.72mm
  • 48mm threads
  • Minimal knurling only on top
  • Highly reflective interference filter
  • Inner retaining ring does have notches for easy filter disassembly with a spanner

Real world tests

Bortle 4, Canon 5D mk iii (stock), AT60ED at f/6, ISO1600, 15 min integration (6*150s)
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Bortle 4, QHY168C, Cooled to -10C, AT60ED at f/6, Unity gain, 18 min integration (6*180s)
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Bortle 9, Canon 5D mk iii (stock), AT60ED at f/6, ISO1600, 10.5 min integration (7*90s)
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Bortle 9, QHY168C, Cooled to -10C, AT60ED at f/6, Unity gain, 15 min integration (5*180s)
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Reader Rating34 Votes
60
Pros
Low cost
Easy to disassemble for DIY mods
Cons
Poor star color with DSLR
Limited formats
CLS concept outdated with move to LED streetlights
82
Purchase from:
  1. I bought the same filter, I also bought the Baader Fringe Killer to use on my 503 ED80 and my Meade LX85 R5 5″ f/5.8 Refractors to help eliminate the Chromati Aberration.

  2. Thanks for posting these and the video. I shoot with an unmodified DSLR in bortle 8 skies and am looking for a filter. Was thinking of trying the SvBony, but it looks like I see chromatic aberration or similar artifacts on the stars.

    I am confused by your comment about the filter being ‘outdated’. Doesn’t the L-Pro pass even more light in the mid-spectrum? Also, you mention bad star color for the SvBony, but wouldn’t the L-Enhance be even worse, it has even smaller passbands.

    1. Hi Stan,
      A CLS is a very simple kind of light pollution filter that works on the idea that most light pollution will be in the Yellow-Orange spectrum (sodium and mercury lights) so that is where the major cut-out is. I say outdated since many cities have unfortunately moved to more broad-spectrum LED lighting. There is not any great way to combat this other than narrower band-passes (like the L-eNhance and other dual narrowband filters). Yes, you are right that star color is even worse with these dual narrowband filters so it’s a tradeoff between better contrast on the emission nebulae or better star color.
      Cheers, Nico

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Final Score