Quote:
Originally Posted by waynehoskins
How is a camera feed through a computer any brighter than a direct camera feed?
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I had the very same question.
Balex, some of the stated desires seem to conflict. For example, you say you want a DLP projector because it is video then later in the same post say you are thinking of running it all through a computer and also note that you are not worried about the lighting being accurate or color rendition. Or that you note that contrast is important in the projector selection but then do not seem to be addressing the image contrast, which is what actually matters, and seem to be assuming that you can control any ambient light on the screen and have not even discussed the screen type or surface material, all of which relate to the perceived image quality and the audience area you are serving.
If you are taking the composite video output of a consumer digital camera, running into an unknown PC capture card, processing that in a $130 PowerPoint add-on and the running that out of the PC to a very inexpensive projector intended more for presentations to a small audience, that may provide an image that you may find acceptable (it also may not) but I frankly don't think I'd worry too much about the specific projection technology used.
You also seem to be thinking front projection when rear projection would be much more common for this type of application and for many good reasons. Think about how between the screen, projector, camera lighting and room lighting you are going to avoid interfering with the audience's viewing the image or keep from casting shadows on the screen. The mention of a 70" x70" screen also shows some possible misunderstanding as that is not a video format and with the 1024x768 projector noted you'd actually have a 52.7" high by 70" wide image. A 70"x70" screen, or a square format screen in general, would not usually be a good choice when you are projecting standard computer and/or video images. And since you noted you will be switching between video and computer images, that 53" x 70" image size is probably good if your furthest viewer is maybe 25' to 35' away, but that might not work for an audience of 400.
A couple of corrections. Rear screen projection is not brighter, with the same screen gain front and rear projection would provide the same brightness. However, rear projection is less sensitive to ambient light and thus can result in a higher image contrast for the same brightness. DLP does not tend to be brighter, X
ANSI lumens is X ANSI lumens regardless of how it is generated, but again, the higher contrast may make it appear brighter. I think the important thing to get from this is that perceived image brightness involves several factors other than the projector brightness and those other factors need to be considered. For example, keeping the same white level but making the blacks blacker actually makes an image look brighter by increasing the contrast ratio even though the peak brightness did not change.
It might really help if you better defined the application. Rather than focusing on the equipment, what are you trying to do and what are your goals? There may be big differences between something that simply puts an image on the screen and what you really need to do or the impression you are wanting to give. This might also help resolve some of the differing indications of your priorities and goals.