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LP850
IR Longpass Filter

In some near-IR imaging applications, the total amount of ambient near-infrared light can be overwhelming, in which case an LP850 filter may be the best choice for eliminating as much of that interference as possible. In cases where the spectral response of the camera beyond 900nm is at or near zero, the LP850 filter allows a manageable amount of light to reach the sensor array.

Please note that we recommend LP830 longpass filters over LP850 longpass filters for 880nm LED lighting applications. LP850 filters do not reach peak efficiency at 880nm, and this better transmission (over the better blocking of the LP850 filter) makes LP830 the filter of choice.

MidOpt single substrate filters are supplied with hard-coated surfaces to improve transmission and inhibit staining. Staining is a problem common to infrared filter glasses that can be found particularly on unprotected polished surfaces. This problem manifests itself as a cloudy, white film that etches into the polished glass surfaces. Over time, staining can greatly reduce transmission and resolution, and cannot be simply wiped away. Factors determining the time required and severity of staining include the year-round heat, humidity and air quality of the surrounding area. In certain environments, coatings are an absolute necessity.

excel icon 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.

filter sizes chart

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

 

 

 

 

 

LP850 transmission curveTransmission chart (typical)
Passes 850nm and above
Absorbs 840nm and below

Wavelength in nanometers
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

transmission in nanometers
95.53
95.54
95.52
95.48
95.46
95.42
95.30
95.29
95.22
95.11

95.00
94.91
94.72
94.65
94.47
94.23
94.00
93.78
93.41
92.88

92.30
91.36
89.86
85.95
77.59
60.69
35.54
13.99
4.09
1.04

0.27
0.08
0.03
0.01
0.00
0.00
0.00
0.00
0.00
0.00

0.00
0.00
0.00
0.00
0.00

 

Wavelength in nanometers
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

transmission in nanometers
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