Two different spectrum shapes
Narrow band pass filters and short pass filters are often considered together, because both shape a spectrum, but they do different jobs. A narrow band pass filter passes a narrow band and rejects light on both sides of that band. A short pass filter passes light on the long wave side of a cut-off edge and rejects light on the short wave side. That shape difference is the whole comparison: a band versus an edge. Buyers who start from the shape they need will choose correctly more often than buyers who start from a product name.
When a band is the right shape
Choose a narrow band pass shape when your system works with one band at a time and neighbouring bands would interfere with the measurement or the image. The narrow band pass category is described on the narrow band pass filters page: it allows a specific band of light signals to pass, with a narrow pass band. The inquiry items for that shape are the centre wavelength or wavelength band, the bandwidth or pass band behaviour, the rejection behaviour outside the band, the size and shape, and the substrate material.
When an edge is the right shape
Choose a short pass shape when your system needs to remove short wave light while keeping longer wave light, or when it needs a clean cut-off edge as part of a larger assembly. The short pass category is described on the short pass filters page: it reflects the short wave region and transmits the long wave region. The inquiry items for that shape are the cut-off edge or wavelength region, the transmission behaviour on the long wave side, the rejection behaviour on the short wave side, the size and shape, and the substrate material.
What this comparison does not do
This comparison does not publish a specification value comparison table for the two families, because no deep specification tables have been documented for either line. It compares definitions and use contexts only. Buyers who need values for either family should state the shape they need and the wavelength region it applies to, and ask for confirmation in the inquiry. Please confirm the specification, quantity basis, and delivery basis in your inquiry before ordering. For the wider family, see interference filters and the interference filter guide.