Hi there, thank you for your question on our TK700 projector. Please be informed that since image processing is required for the keystone function, input lag will be slightly longer. But the smoothness in games would not be affected when the keystone is enabled. Latency will hardly be noticeable with keystone function enabled, as lag time merely increases no more than 1 frame (4ms~16ms).
If you have further questions regarding the TK700, please feel free to contact us using the Online Chat service on our BenQ official website, and our customer care specialist will be more than happy to assist you. Thank you!