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Author Topic: Bulb layout in Digital units Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 03-30-2011 01:56 PM                     Okey, a newbie question here: In all we know that with 35mm projection in majority of the applications (Cinemecannica's did have side shooting lamphouses for the V8 setups), the path of light from reflector thru film, lens to screen has always been in a straight line. Now, comes digital where the light path gets bent everywhere inside the unit via prism arrangement until it leaves the lens to screen. You would think that light loss is great in this form of application. Now, the newbie question: why is the bulb layout set at 90 degrees in the majority of the applications - from small LED/DLP table units to cinema applications intead of firing forward to the lens? Granted, it's prob due to the light engines to where it looks like I just answered my own question here, but you'd think that there would be more light response if the path of light could be straighter with redesigning of the light engines to accept foward firing bulbs. thx- Monte  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 03-30-2011 06:19 PM                     Among other things, DLP is reflective technology. And there are three DLPs in cinema projectors. There's no way to have a straight forward lightpath with a reflective imager. Same with LCOS. Some machines have an additional 90 degree mirror from lamphouse to light engine - I guess, mostly to shorten total machine length. But that doesn't mean these machines loose that much light. As a matter of fact, due to new designs of mirrors, integrators, 'digital bulbs', prisms, coatings, etc. the light efficiency of series-2 1.2" DLPs is even better than that of traditional 35mm lamp houses. At least for 2D. - Carsten  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 03-30-2011 09:07 PM                     Okey, that makes sense of the reflective format being that I forgot of DLP using those microtilt mirrors - one can tell that I needed to be educated in DLP cinema some more since I'm now more into floor operations than booth operations... thx-Monte  |  IP: Logged Dave Macaulay Film God Posts: 2321 From: Toronto, Canada Registered: Apr 2001 posted 04-02-2011 04:57 PM                     I think a 35mm projector using the light integrator system as in digital video projectors would be a great idea. The integrator evens out the light from the lamphouse and presents a nice flat illumination.  |  IP: Logged

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