MidOpt DB Series Filter DB940
Uniforce Product
Salient Features
Dual Bandpass Filter Visible + 940nm NIR
A DB940 filter passes visible and 940nm LED light. 940nm LEDs do not emit the faint red glow associated with 850nm and other lower near-IR LED wavelengths. Using a DB940 filter over or behind the lens allows full color imaging during the day and covert surveillance at night. However any camera’s spectral response at 940nm will be lower than at other, shorter near-IR wavelengths, so relative sensitivity of each camera’s imaging sensor at 940nm must also be considered.
DB940 Dual Bandpass Filter Visible + 940nm NIR
- Useful Range : 405-650nm, 925-965nm
- FWHM : 250nm, 60nm
- Tolerance : +/- 20nm VIS, +/- 10nm NIR
- Minimum Peak Transmission : ≥90%
- Surface Quality : 40/20
- Compatible LED : 940nm, 950nm
The performance of a filter is based on what happens to light passing through the filter. The apparent color of light reflected off the surface is not a reliable way to judge the filter’s capabilities. Batch-to-batch difference in the apparent color of the coatings or filter substrates can often be easily seen when looking at two examples of the same filter type. The color of the coating does not indicate a disparity in performance.
DB940 Transmission Data
| wavelength | transmission | wavelength | transmission |
| (nm) | (%) | (nm) | (%) |
| 1100 | 1.3 | 720 | 0.03 |
| 1090 | 1.56 | 710 | 0.06 |
| 1080 | 1.5 | 700 | 0.17 |
| 1070 | 1.16 | 690 | 0.53 |
| 1060 | 0.81 | 680 | 1.58 |
| 1050 | 0.65 | 670 | 10.85 |
| 1040 | 0.64 | 660 | 60.24 |
| 1030 | 0.79 | 650 | 88.86 |
| 1020 | 1.29 | 640 | 89.26 |
| 1010 | 2.76 | 630 | 90.24 |
| 1000 | 7.61 | 620 | 91.44 |
| 990 | 20.75 | 610 | 92.5 |
| 980 | 44.28 | 600 | 93.94 |
| 970 | 69.36 | 590 | 94.11 |
| 960 | 84.77 | 580 | 93.64 |
| 950 | 90.75 | 570 | 93.32 |
| 940 | 92.59 | 560 | 92.55 |
| 930 | 89.53 | 550 | 93.87 |
| 920 | 72.02 | 540 | 93.27 |
| 910 | 27.9 | 530 | 93.49 |
| 900 | 6.03 | 520 | 91.15 |
| 890 | 2.17 | 510 | 91.54 |
| 880 | 0.69 | 500 | 91 |
| 870 | 0.32 | 490 | 88.74 |
| 860 | 0.45 | 480 | 87.04 |
| 850 | 0.21 | 470 | 91.14 |
| 840 | 0.07 | 460 | 86.54 |
| 830 | 0.04 | 450 | 89.61 |
| 820 | 0.02 | 440 | 83.04 |
| 810 | 0.03 | 430 | 81.28 |
| 800 | 0.04 | 420 | 86.6 |
| 790 | 0.19 | 410 | 87.73 |
| 780 | 0.35 | 400 | 79.55 |
| 770 | 0.17 | 390 | 40.15 |
| 760 | 0.19 | 380 | 5.89 |
| 750 | 0.17 | 370 | 1.46 |
| 740 | 0.06 | 360 | 0.13 |
| 730 | 0.03 | 350 | 0 |
Available Mounts
Threaded Mount
- Designed for lenses with filter threads, a variety of filter types and stock threaded sizes are available: M13.25-M105
- Larger sizes, 62mm to 105mm, are made to order and are not returnable
- Custom thread sizes are available upon request.
- Threaded mounts are available as black anodized aluminum rings. Rotating mounts with locking thumb screws are generally provided.
Ordering Example:
- Filter: BP470
- Mount Size: M27
Correct Part# is:
- BP470-27
Threaded Mount Technical Drawing PDF
Slip Mount
- Designed for varifocal lenses, wide angle lenses and lenses without filter threads
- Accommodates standard threaded mounts
- Low profile and oversize diameter design prevents wide angle lens vignetting
- Locking set screws and a wrench are provided to secure the adapter to the lens
- Many varifocal and shorter fixed focal length (wide angle) lenses are not supplied with filter threads due to the presence of a protruding, strongly convex lens element. Our slip mount adapters allow standard threaded filters to be fitted securely to these and a large variety of lenses that do not have filter threads provided.
Ordering Example:
- Filter: BP470
- Outside Diameter of Lens in mm: 43mm
Correct Part# is:
- BP470-S43
Slip Mount Technical Drawing PDF
C/CS Camera Mount
- Designed to thread directly into any C/CS mount camera between the lens and sensor
- Wrenching slots aid in threading the filter into the camera body. A wrench is supplied with each filter.
- Helpful in applications with space constraints
- Can be used with wide angle lenses that do not accept filters at the front end to prevent vignetting
- C/CS mount filters are available in a standard 1mm thickness
Ordering Example:
- Filter: BP470
- Mount Size: 25.4
Correct Part# is:
- BP470-25.4
C/CS Camera Mount Technical Drawing PDF
Unmounted & Custom Size
- Any MidOpt filter type can be provided as an Unmounted filter
- Custom shapes and sizes are typically fabricated with one day to two week lead times
- Custom filter types with longer lead times can also be quoted. Please contact us regarding feasibility.
Learn More About
› Learn More About Day/Night Imaging in Color Applications
› Learn More About the Use of Dual Bandpass Filters in NDVI/Agricultural Inspection
