I have the following problem. I have a sensor with 1mm diameter and I need to have 500 urad (microradian) field of view. If I understand correctly, that would generally mean that I need to use 2meter focal length. However, I have 20cm space. It is acceptable to defocus the image if necessary. Can I achieve the required FOV for this sensor and distance at the receiver by using a combination of two or more lenses?