# graduated neutral density filter
**Wikidata**: [Q1543899](https://www.wikidata.org/wiki/Q1543899)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Graduated_neutral-density_filter)  
**Source**: https://4ort.xyz/entity/graduated-neutral-density-filter


## References

1. Freebase Data Dumps. 2013