MidOpt DB Series Filter DB395 / 870
Uniforce Product
Salient Features
New Dual Bandpass Absorptive Visible + NIR
DB395/870 Dual Bandpass Filter passes UV-Violet and infrared wavelengths, effectively blocking all green and red light. These filters have traditionally found use in NDVI-type imaging applications. When using a single camera modified for aerial agricultural surveillance, incorporation of these so-called “Superblue” or “Infrablue” filters allows reflected near-infrared light (745-970nm) to be captured in the camera sensor’s red channel and reflected violet light (375-425nm) to be captured in the sensor’s blue channel (the green channel is not used). Even when using an inexpensive consumer camera (that has first had its IR blocking filter removed), this easy separation then makes it possible to post-process the red and blue channels for NDVI by performing the calculation: NDVI = (red – blue) / (red + blue). Healthy vegetation will absorb (not reflect) blue light and strongly reflect near-infrared light. While “Superblue” filters similar to DB395/870 have seen much use during recent years, for far better wavelength separation and contrast we strongly recommend the use of our newer DB475/850 or DB660/850 dualband filters instead.
DB395/870 Dual Bandpass Absorptive Visible + NIR
- Useful Range : 374-425nm, 745-970nm
- FWHM : 110nm, 375nm
- Tolerance : +/- 10nm
- Minimum Peak Transmission : ≥90%
- Surface Quality : 40/20
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.
DB395/870 Transmission Data
| wavelength | transmission | wavelength | transmission |
| (nm) | (%) | (nm) | (%) |
| 1100 | 55.15 | 670 | 0.01 |
| 1090 | 57.94 | 660 | 0.01 |
| 1080 | 60.71 | 650 | 0.01 |
| 1070 | 63.35 | 640 | 0.00 |
| 1060 | 65.82 | 630 | 0.01 |
| 1050 | 68.12 | 620 | 0.00 |
| 1040 | 70.29 | 610 | 0.01 |
| 1030 | 72.34 | 600 | 0.00 |
| 1020 | 74.24 | 590 | 0.02 |
| 1010 | 75.97 | 580 | 0.10 |
| 1000 | 77.50 | 570 | 0.40 |
| 990 | 78.95 | 560 | 0.53 |
| 980 | 80.27 | 550 | 0.31 |
| 970 | 81.50 | 540 | 0.21 |
| 960 | 82.50 | 530 | 0.27 |
| 950 | 83.71 | 520 | 0.56 |
| 940 | 84.69 | 510 | 1.21 |
| 930 | 85.69 | 500 | 2.73 |
| 920 | 86.56 | 490 | 6.20 |
| 910 | 87.45 | 480 | 14.20 |
| 900 | 88.34 | 470 | 26.99 |
| 890 | 89.01 | 460 | 41.63 |
| 880 | 89.77 | 450 | 55.83 |
| 870 | 90.85 | 440 | 67.62 |
| 860 | 91.39 | 430 | 76.81 |
| 850 | 92.05 | 420 | 83.98 |
| 840 | 92.68 | 410 | 88.62 |
| 830 | 93.36 | 400 | 89.91 |
| 820 | 93.98 | 390 | 86.32 |
| 810 | 94.58 | 380 | 77.11 |
| 800 | 95.11 | 370 | 64.33 |
| 790 | 95.36 | 360 | 50.07 |
| 780 | 95.10 | 350 | 37.32 |
| 770 | 94.60 | 340 | 27.49 |
| 760 | 91.85 | 330 | 20.37 |
| 750 | 85.74 | 320 | 15.76 |
| 740 | 74.76 | 310 | 13.34 |
| 730 | 57.73 | 300 | 11.97 |
| 720 | 35.23 | 290 | 8.45 |
| 710 | 14.57 | 280 | 2.46 |
| 700 | 3.65 | 270 | 0.29 |
| 690 | 0.57 | 260 | 0.02 |
| 680 | 0.08 | 250 | 0.01 |
Click Pic to Enlarge
MidOpt StablEDGE™ optical filters are specifically designed to be less susceptible to effects from angular shifting seen when optical filters are placed in front of short focal length (<12 mm) camera lenses.
StablEDGE™ filters take advantage of absorptive filter glass to form the leading
edge of the filter passband.This assures no shifting in this region, even when the
lens FOV exceeds 100°.StablEDGE™ designs are less angle-of-incidence sensitive, inherently more rugged, and are environmentally stable.
Available Mounts
Threaded Mount
- Designed for lenses with filter th11.97reads, a variety of filter types and stock threaded sizes are available: M13.25-M1058.45
- Larger sizes, 62m2.46m to 105mm, are made to order and are not returnable
- Custom thread sizes a0.29re available upon request.
- Threaded mounts are avai0.02lable 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
> Learn More About How to Minimize the Effects of Short Shifting
