The optimal viewing distance for a 40-inch TV is typically around 5 to 8 feet (1.5 to 2.5 meters). At this distance, you should be able to enjoy the full resolution of the TV without any loss of detail or image distortion. However, the ideal viewing distance can vary depending on your personal preferences, the room lighting conditions, and the content being watched.
If you sit too close to the TV, the image may appear pixelated or blurry, and you may need to move your head around to see everything clearly. If you sit too far away, you may miss out on some of the details and experience a reduced sense of immersion in the content.
In general, it's a good idea to experiment with different viewing distances to find the one that feels most comfortable and enjoyable for you.