LP920
IR Dichroic Filter

Recommended for use with infrared LEDs

The single substrate, hard-coated LP920 IR Longpass filter has been designed for use with 940nm LED illumination. Its excellent lower wavelength blocking (10-5 blocking into the near-IR) allows these filters to block visible emissions (particularly the red "glow") when placed in front of multi-spectral lighting used in semi-covert or photographic darkroom applications. Note that the "pink" reflective surface must be mounted facing toward the light source in these situations.

It is also a useful filter for imaging applications which employ IR vidicon or InGaAs cameras.

Download Excel Spreadsheet with data and curve for this filter.

Examples of filter effectiveness.

Standard Threaded Mounts:
We offer standard filter sizes from stock – 22.5mm to 62mm – for same- or next-day shipping. Larger filters – 67mm to 105mm – are made to order and are normally not returnable.

Click here for PDF drawing of standard mounts

Slip Mounts:
If your lens does not have threads for mounting a filter, Slip Mount adapters are available. Slip Mounts can attach a regular filter to a lens or attach a very large filter to accommodate a wide angle lens. Please call to order Slip Mount adapters.

C-Mounts:
3mm thick threaded mount for adding a filter between lens and camera
Click here for PDF drawing of c-mounts

Transmission chart (typical)
Passes 920nm and above
Absorbs 690nm and below
Reflects 690-910nm

1100
1090
1080
1070
1060
1050
1040
1030
1020
1010

1000
990
980
970
960
950
940
930
920
910

900
890
880
870
860
850
840
830
820
810

800
790
780
770
760
750
740
730
720
710

700
690
680
670
660

97.55
97.55
96.94
95.79
94.75
93.87
93.71
94.09
94.95
95.87

96.51
96.63
96.33
95.68
94.79
94.08
94.27
91.53
70.99
35.52

13.70
5.55
1.17
0.45
0.20
0.09
0.07
0.03
0.02
0.00

0.01
0.02
0.02
0.02
0.01
0.02
0.01
0.02
0.01
0.00

0.00
0.00
0.00
0.01
0.00

650
640
630
620
610
600
590
580
570
560

550
540
530
520
510
500
490
480
470
460

450
440
430
420
410
400
390
380
370
360

350
340
330
320
310
300
290
280
270
260

250
240
230
220
210

0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00

0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00

0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00

0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00

0.00
0.00
0.00
0.00
0.00