Ensuring surveilled objects are in focus is a common concern. In this report, we examine lenses claiming to offer a massive depth of field (MDOF), allowing objects in both the near and far fields to remain simultaneously in focus. This test evaluates GBO's InfinityLens lenses.
[Update 2012: GBO is out of business.]
Inside this report we'll reveal our findings based on side-by-side comparisons of the GBO InfinityLens lenses versus a commercially available lens. We provide image captures to allow the viewer to participate in the evaluation.
Depth of Field Performance
We tested the 14.0mm, 30.4mm and 52.3mm manual iris GBO Infinity lenses against a commercially available 5-50mm auto-iris lens using the same 4CIF IP camera for each trial.
In the first trial of 14.0mm GBO lens vs. 5-50mm commercially available lens we adjust the focal length of the 5-50mm control lens so that the horizontal FoV is similar to the 14.0mm GBO lens' horizontal FoV. We then adjust the manual iris so that light levels and aperture sizes are relatively equal.
We then set focus to license plate/person subjects at 20 feet (near) and capture images at the 20ft (near), 50ft (mid) and 100ft (rear) of the same license plate/person subjects. This procedure is done for both the GBO and commercial lens.
We repeat focusing at the 50ft (mid) and 100ft (rear) locations and then capture images at the 3 (near, mid, and rear) locations for these two focus points. This procedure is done for both the GBO and commercial lens.
We then repeated the same steps for the 30.4mm and 52.3mm lenses, with the following adjusted reference distances:
- 30.4mm focal length lens test - near (25ft), mid (50ft), rear (100ft)
- 52.3mm focal length lens test - near (100ft), mid (250ft), rear (450ft)
In our low-light tests we capture images of the 14mm GBO InfinityLens lens at a 1.0 Lux and 0.3 Lux level. We then repeat the procedure with a commercially available lens. We then compared the two lenses at each lux level for differences in image quality.
Related Lens Reports
Compare to our test results of Theia Technologies who claim to provide a much wider FoV and eliminatinon of barrel distortion typical of fish eye lenses . Also, check out this training report: Using Lens Calculators to further your knowledge about lenses.