AVS Special Member
Join Date: Aug 2001
Location: BOSTON --- MA ---
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I own a LG HX300G (rated 270 lumens, 2.000:1 contrast ratio) and have been using it an average of 10~12 hours daily for the past 10 months (over 3.300 hours, for those counting); This pj uses the Luminus Devices LED chipset PT-54 (1024x768) which i would describe as the predecessor of this new Pico Chipset (1280x800) used in the Vivitek Qumi.
After reading some of the recent posts i decided to recheck both my recollections and math; According to test reports at Projector Central and at Projector Reviews the LG HX300G does indeed put out 250 lumens at its highest lamp setting, a figure that is very close to listed spec.
Considering the similarities of these LED chipsets which are BTW made by the same manufacturer i would expect the Vivitek Qumi to perform likewise : if the company is claiming 300 lumens and a contrast ratio of 2.500:1 it wouldn't surprise me that after calibration the user would get about 270 lumens...
I rechecked my figures with the screen calculator from Projector Central and according to it, using my current 1980's semi-curved silver, XX-high-gain (dealer claimed gain of 10.0, i could only estimate it up to 7.0 !), 76" diagonal screen, i am getting 49 ft-L ! Even if the screen gain was lowered to 5.0 that would still make it an image of 35 ft-L, which is still very/very bright. Sometimes depending on the amount of white shown onscreen it actually feels like it hurts my vision, as in too much brightness in too large an area, and depending on content i have to lower the lamp output from medium to low.
I realize my screen is rather small and exhibits a ridiculous gain but to my eyes, in my darkened room, it's comparable to a plasma image considering its figures of 35 ft-L and its implied minimum black level of 0.018 ft-L, compared to tested plasma and LCD displays at 30~35 ft-L and "Pioneer Kuro" black levels of 0.002 ft-L...Not too shabby, hmm ?
If this littlle Vivitek "beautE" performs as spec'd i would expect it to throw a beautiful image on a 92" diagonal 2.4 gain screen (14 ft-L, very close to THX recomendation) for only $500 plus cost of screen.