BP635
Red Bandpass Filter

Recommended for use with red laser diodes and LEDs

The MidOpt BP635 filter is recommended for 610-650nm LED and laser diode lighting. Because of its broad bandwidth and high peak transmission, the single substrate, hard-coated BP635 works very well for all lighting applications in this range.

Colored longpass filters have long been recommended for use with monochrome cameras to aid in increased contrast and resolution. These filters block UV and shorter visible wavelengths, and pass longer wavelengths of light. Except in those few cases where an IR blocking or other shortpass filter is incorporated into the camera or sensor, MidOpt will often recommend the use of a broad color bandpass filter (whose designs incorporate these longpass filters) over color longpass filters alone.

Next to the BP660 filter, BP635 filters are our second most popular filter type.

Example:

(left) Monochrome image in white light doesn't show the code information.
(center) Photographic filter doesn't help at all as there is too much ambient near-IR.
(right) MidOpt BP635 helps improve contrast tremendously.

More examples

Download Excel Spreadsheet with data and curve for this filter.

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 600-660nm
Absorbs 200-590nm
Reflects 670-1080nm

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

48.62
55.46
25.35
8.89
4.22
2.58
1.64
1.28
1.14
1.25

1.74
2.24
1.37
0.61
0.28
0.23
0.16
0.25
0.31
0.79

0.91
0.57
0.53
0.24
0.19
0.21
0.33
0.63
1.16
0.78

0.44
0.37
0.41
0.70
0.92
0.75
0.71
1.09
2.38
3.62
3.63

6.59
21.42
55.70
79.46

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

96.10
90.63
94.58
93.73
91.58
80.91
45.04
6.04
0.19
0.00

0.01
0.01
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
0.01
0.00
0.00
0.00

0.00
0.02
0.00
0.01
0.00
0.00
0.00
0.00
0.00
0.00

0.00
0.00
0.00
0.01
0.03