IR cameras are (arguably) the best value for the buck. Here are some issues I've encountered and how to possibly remedy them.
Considering that the IR illumination comes exclusively from the LED's within the camera body, LED's are not generally known for sending hot beams of light over impressive distances - They tend to "glow" like a jar of fireflies. Try comparing a maglight flashlight with an LED flashlight. The LED's may be blinding at close range, but only the maglight will hit the back fence. Moving the camera closer to the target area is the simplest solution but rarely the most practical as you will, no doubt, loose coverage of other areas.
If you must have more IR light at a distance, consider a separate IR illuminator and place it out there (closer to the target area) to suppliment the camera's IR.
Avoid pointing cameras into street lights, motion lights, the sky or into oncoming traffic as this will compromise image quality. Unless you are hunting UFO's, any skyview in CCTV is a waste of valuable viewing area. Even the night sky can provide enough light to offset the balance of your image and cause the subject area to become dark.
Consider a second IR camera with a "crossover" viewpoint from another location. I've had great success using two cameras on the front corners of my garage (right camera-looks-left, left-camera-looks-right). Some guy knocked out one of my cameras one night...not realizing that the other (crossover) camera captured a clear image of him, which landed him in jail. All my cameras work under this "buddy system".
Hope this helps a bit. Good luck.
