Fresnel Lenses – A missed opportunity?

Cockpit builders usually settle on TV screens or projecting an image on a curve screen for their simulators. The pinnacle of image generation has always been collimated – this allows you to view an image with parallel rays and does not diverge; the image has correct perspective with depth like perspective. Collimated setups require dedication – there have only been a few attempts; Gene created the first DIY Collimated display in 2011.

The importance of depth perception for pilot training became more apparent after several visits to professional flight simulators around the world and Certified Level D trainers – TVs and projectors on a flat screen appeared two dimensional when compared to the collimated setups.

Collimated Displays require a fair amount of space and a controllable vacuum pump system for the mylar mirror. What are the visual setup alternatives which could further the simulation? Fresnel lenses appear like they could be a viable solution – they provide magnification of the image and a ‘pseudo-collimated’ effect; the image appear to converge behind the screen providing depth.

Michael Black’s Fresnel Lens Setup; photo from Airplanista Aviation Blog Interview (2013)

Roland van Roy successfully implemented a fresnel lens in his setup but also notes some screen distortion and colour aberrations. Michael Black mounted four large fresnel lens in front of his TVs which surround his 767 simulator and reports that ‘Fresnel lenses give a 2D rendering from the television a 3D effect’ (Airplanista Aviation Blog, 2013).

Michael Black 767 fresnel lens setup from inside the cockpit; photo from Airplanista Aviation Blog Interview (2013)

Rick Lee wrote on this topic on his website – its no longer accessible, but fortunately still available on the Internet Web Archive and can be downloaded here. Boeing even did extensive research on fresnel lenses and proposed using it in their Flight Simulators (John Amery, Harry Streid).

It is a shame fresnel lenses have been overlooked in the community (perhaps because of the price of large lenses); they should be able to provide a pseudo-collimated effect for home flight simulator setups providing more depth and immersion and can be made to work together with traditional flat 2D TV or projector screens.

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