NiSi Optics USA has launched its new 150mm Explorer Collection of square neutral density (ND) filters, which it claims are twice as strong as other glass filters on the market thanks to a ‘special glass hardening process.’

The 150mm Explorer Collection is identical to its 100mm predecessor in all but size and work with any of NiSi Optics USA’s S5 and Q system 150mm filter holders. Like the 100mm options, the 150mm Explorer Collection is made from B270 tempered glass and includes the following 2mm-thick filters: 10-stop ND1000, 6-stop ND64, 3-stop ND8, 3-stop ND8 Medium Graduated ND and 2-stop ND4 Reverse Graduated ND.

What sets the Explorer Collection apart from other glass filters on the market is their durability. NiSi Optics USA says it treats the filters via a ‘special glass hardening process’ that doubles the strength of the glass with ‘no visible loss of image quality.’ While that sounds like quite the claim, the above video appears to back up the claims.

Each of the five filters in the 150mm Explorer Collection retails for $198 and is currently available to purchase through NiSi Optics USA online shop and authorized retailers.

Press release:


Hardened Glass Filters Now Available for The 150mm System

NiSi Optics USA have just launched the brand new 150mm Explorer Collection of neutral density filters which are compatible with all of our 150mm filter holder systems including very popular S5 filter holders and Q filter holders.

The new range of 150mm Explorer Collection filters include the 10 Stop ND1000, 6 Stop ND64, 3 Stop ND8, 3 Stop ND8 Medium Graduated ND and 2 Stop ND4 Reverse Graduated ND. The Explorer Collection range of filters can be used in combination with the 150mm optical glass range of neutral density filters. Each filter in the NiSi 150mm Explorer Collection is priced at USD$198.

When it comes to durability, the NiSi Explorer Collection filters are stronger thanks to the special glass hardening process that makes them up to double the strength of typical glass filter. For photographers shooting in more adventurous situations and harsher landscapes, the Explorer Collection filters may be the better choice when compared to our optical glass filters as they offer increased durability that will provide a great investment over time.

While using the NiSi Explorer Collection filter range, there is no visible loss of image quality when compared to the NiSi range of optical glass filters. The proprietary manufacturing methods used by NiSi ensure there will be no impact on visible image quality when using the tempered glass within the NiSi Explorer Collection series of filters.