750W is not monstrous at all for 6x7! 250W is normal for 35mm. But the area of a 6x7 slide is 4.5 times as large. You need much more light to project it with the same brightness (too busy now to find out how much more). I use a 1000W Goetschmann G67 projector for my 6x7 slides. This is the smallest Goetschmann model. Here is a link to the producer. It is perfectly suitable for a living room. I used to project on a 1.5m2 screen but meanwhile changed to 2m2. 50" should be something like 1.3m2. 750W will be fine.
Originally Posted by polyglot
When I started projecting 6x7 slides, I used an old Leitz made Linhof 6x7 projector. I cannot recommend such an old projector because they are too dim. If you really want to impress your friends you need a more modern projector with an excellent lens. The Goetschmann comes with a Schneider-Kreuznach 150mm f2.8 lens.
Last edited by Joachim_I; 10-22-2009 at 05:49 PM. Click to view previous post history.