immersive projection environments
Hi, did you buy this projector already? how is it working?... I also have a mirror for my Dome
I know this is an old thread. But, the topic is certain to always be current, as projectors are constantly changing.
I am looking for a projectors to use with a spherical mirror. There is one thing I have not been able to discover. Where does the projector focus? Very early in my investigation, I had assumed that the projector would focus on the distance from the lens, to the mirror, and then to the surface of the dome. But, I quickly realized that this would only be true for a flat mirror, and that the spherical mirror would change things.
I want to be confident I purchase a projector capable of focusing at that distance. Is there a general rule about how to calculate the actual focus distance?
Thank you for any advice or information.
I eventuallycame up with the correct search terms to find the answer. Paul Bourke commented on another thread ,Please;
" note also that the choice of projector has focus constraints. Assuming you are using the normal 60cm mirrors, then your projector needs to be able to focus on a flat wall such that the image is around 45 to 50cm wide. Whether you achieve this with projector position or zoom doesn't matter."
I don't have a definite answer on the focus issue. But, there is no question that you do need to take the projector towards the extreme close-up end of the focus range. I've been experimenting with a security mirror with a fairly gentle curve, rather than a half-dome. But, I hope to obtain one and finally know, by trial and error.