Are you interested in 2D only or you want to watch 3D. 3D has much more light loss and it is more difficult to find a projector that will be bright enough with your for good quality 3D viewing with your screen size and gain. There are actually very few projectors that include lens memory for zoom, focus and ideally also lens shift that automate going between 1.78:1 mode and 2.35:1 mode. Basically Panasonic (the inventor of the lens memory feature), JVC and Sony are the manufactures of moderate priced projectors that offer this feature. The Panasonic PT-AE8000 is probably the least expensive model to offer this feature. It only offers about 600 lumens of light output when calibrated for the most accurate grey scale and color which will provide about 12 ft. lamberts brightess from the screen which is at the very lower end of what is generally considered acceptable brightness in a totally light controlled room. At the projector's lamp ages the projector's lumens will go down so this is not an ideal situation. The Panasonic does however have some brighter, but less accurate, modes, with 2 or more times the lumens output of the most accurate mode, that you may very well find acceptable. Bottom line for the Panasonic is it may be usable for 2D viewing.
The JVCs have somewhat higher lumens (on the order of 900 lumens with a new lamp) output in their most accruate mode and overall these would probably be a somewhat better choice for 2D viewing if you want accurate colors and grey scale. JVC's however do not have a high luman mode that is much brghter than the most accurate mode.
The Sony VW95 has lens memory and has an output similar to the JVCs.
None of these projectors will be very birght for 3D viewing where the light to the eyes (thru the 3D glasses) may only be 20% to 25% of what you get for 2D viewing.
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