For low-level aerial photography, filters are not required as long as you are below which altitude?

Filters in aerial photography often serve specific purposes, such as reducing glare, improving contrast, or enhancing colors. For low-level aerial photography, these considerations vary based on the altitude of the flight. Below a certain altitude, the atmosphere's effects are generally diminished, allowing for clearer and more vibrant images without the need for filters.

In this context, the altitude of 5000 feet is significant because it usually represents a point where the impact of atmospheric haze and light scattering becomes negligible. At this altitude or lower, photographers typically find that the enhanced clarity and quality of images render additional filtering unnecessary. Therefore, photographers can achieve satisfactory results without carrying extra equipment, allowing for simpler setups and more flexible shooting conditions.

The other altitudes listed may still have atmospheric influences that require compensation through filters, affecting image quality or color fidelity. Thus, keeping the altitude below 5000 feet generally suffices for clean, useful aerial photography without needing to worry about the complications that higher altitudes might introduce.