Setting vertical lamphouse!

[MarinBNM]

I'm using 350mm diameter mirror and XBO 900W vertical lamp, so I want to know what is distance from film gate to center of lamp?

[Jensg]

Difficult, there are differend mirrors available. some of 770mm, some of 815mm, some of 675mm. the problem is, that only a 900watts mirror works in combination with a 900watts 'help'-mirror (don't know the exact name of the little mirror near the lamp). correct position and justage is reached at the position, when lamp, big mirror and little mirror are so close together, that you can't see the arc when looking from the side. maybe only a small slit is left. if you using a mirror for 1600watts lamp or 2500watts lamp, its not possible to reach an even bright light on the screen. the edges on top an below will be darker than the middle of the screen.

i hope you understand my not well english in the moment.

Jens