Author in old steam railway tunnel used for long distance stereo research.

Gillam, B., Palmisano, S., & Govan, D.G. (2011). Motion parallax and binocular disparity for depth interval estimation beyond interaction space. Perception, 40, 39-49. Palmisano, S.P., Gillam, B.J., Govan, D., Allison, R.S., & Harris, J. (2010). Stereoscopic perception of real depths at large distances. Journal of Vision, June 24, 2010, vol. 10 no. 6 article.