10x optical, 30x optical or 121x total zoom… what is best?
First let’s clarify which is which.
Optical zoom uses traditional glass lenses to make the target appear closer to the camera without sacrificing the image quality. The same number of pixels are used, and the pixel size remains unchanged.
Whereas digital zoom crops a section of the image and then enlarges the pixels to fill a space, making it the same size as the uncropped image. This replicates the same effect as optical zoom, however, this process does affect the image quality since less pixels are used and the pixels are enlarged.
When capturing images from a UAV, the purpose of the images and video after the operation will ultimately determine which type of zoom is best suited to your mission.
When using an optical zoom lens, the amount of zoom is limited by the focal length of the lens.
For digital zoom, there is no limit, however, there is a point where the image will become useless as the pixels become too large to allow for a clearly defined image.
A combination of optical zoom and digital zoom much like that seen on most digital point and shoot cameras provide the operator with the option of entering the digital zoom region, should it be required.
All types of zoom present a challenge of keeping the camera steady enough to take a clear and focussed image.
Using a gyro stabilised gimbal is the perfect way to ensure that an optical zoom sensor has the stable base required to provide clear imagery at high zoom levels on a moving platform.
Ultimately, the decision of optical vs digital is driven by the results required by the mission.
If image quality is less important than the content of the image, then digital zoom can be used to ensure mission critical data is captured.
If image quality is the most important aspect of the image, then digital zoom should be avoided.