Why dazzle camouflage depended on range and optics

What made some dazzle camouflage schemes ineffective?

Their effect diminished at close range and could fail when a pattern was designed for a different type of optical rangefinder.

No single dazzle scheme was universally worst because the camouflage could work under the conditions for which it was designed. Its value declined in close-range combat, where the visual deception no longer solved the same gunnery problem. Some British patterns were tailored to one form of rangefinder and performed poorly against a different German system. Once designers understood that mismatch, they developed schemes that worked better against German instruments.