Quick answer
Choose the Schott RG780 if you need a 50 x 50 mm square filter for wide-field applications; choose the Schott RG830 if a 25 mm diameter round filter and a lower price better fit your setup and budget.
Size and shape matter for mounting
The RG780 comes as a 50 x 50 mm square, while the RG830 is a 25 mm diameter round. Square filters are easier to hold in standard square filter holders or large-area setups. Round filters often fit threaded lens mounts or small optical cages without adapters. Your existing hardware should guide this choice.
Transmission edge: 780 nm vs 830 nm
Both filters are Schott longpass glass, but they block different wavelength ranges. The RG780 transmits light above about 780 nm, the RG830 above about 830 nm. If your application needs to block visible light up to 780 nm, the RG780 is the correct choice. If you can accept a slightly higher cutoff to reduce near-IR contamination, the RG830 may be preferable.
Trade-offs at a glance
- Schott RG780: Square, 50 x 50 mm, 3 mm thick. Cut-on ~780 nm. Higher price (catalog comparison $35.90, yours $24.77). Best for large-area or square-format systems where the extra size and cost are justified.
- Schott RG830: Round, 25 mm diameter, 3 mm thick. Cut-on ~830 nm. Lower price (catalog comparison $19.50, yours $13.46). Best for compact round-threaded mounts and projects where a slightly higher cutoff is acceptable and budget is tighter.
- Key trade-off: The RG780 offers a lower cut-on and larger area; the RG830 offers a higher cut-on and smaller area at a lower cost. There is no universal winner.
Product facts
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Schott RG780: The Schott RG780 is a 3 mm thick, 50 x 50 mm square longpass filter. The large square format suits wide-field imaging or setups that use square filter holders, giving you more mounting flexibility.
Schott RG780
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Schott RG830: The Schott RG830 is a 3 mm thick, 25 mm diameter round longpass filter. The compact round shape fits standard 1-inch lens threads or small optical cages, and its lower price makes it a budget-friendly choice for smaller sensors.
Schott RG830
Which filter fits your setup?
Best for
- Wide-field fluorescence imaging that needs a 780 nm cut-on and a 50 mm square filter
- Optical setups with square filter holders or large-area sensors
Not for
- Compact systems with threaded 1-inch lens mounts that need a 25 mm round filter
- Budget-limited projects where a 830 nm cut-on is sufficient
