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Topic: Vivitek D96A-BK: measured luminous flux is 19% less than claimed by manufacturer
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Joined: Jun 25, 2017
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Hi all,
I’ve got 2 Vivitek D96A-BK projectors. Manufacturer claims that light output of this model is 6000 ANSI lumens. Using projector I displayed a 3x3 full screen matrix of white rectangles separated with 1-pixel black lines and used a calibrated luxmeter to measure illuminance in 9 points. When measuring I placed luxmeter’s sensor in the center of each white rectangle.
In the projector’s settings I set up Display mode = Bright and Brightness = 10 (maximum value).
I got the following results (values are in lux):

6210 6860 4860
8060 9290 7080
8670 9830 7910

Average: 7641 lux
Distance to screen: 180 cm
Screen area: 0,6394 m2
Calculated luminous flux: 7641 * 0,6394 = 4886 lux (19% less than claimed by manufacturer)
Brightness uniformity: 4860/9830 = 49%

Results for the second projector:
Calculated luminous flux: 5113 lux (16% less than claimed by manufacturer)
Brightness uniformity: 45%

What could be the cause of the fact that measured luminous flux is significantly less than claimed by manufacturer? Should I change some additional settings in projector? Are my projectors defective? Or measuring technique used is wrong? Or should I use not just calibrated luxmeter but some special “ANSI-calibrated” one? Please give me some advice or just your thoughts about that.
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Joined: Mar 28, 2005
Posts: 11,809
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That's actually pretty darn good for a projector. Most manufacturers are far more off on their brightness claims.

The reality is that most manufacturers claims of brightness are closer to market garbage than reality. Your extensive testing of a fairly cheap projector is commendable.

So, here are some things:

You have to move the projector as close to the screen as allowed by the zoom of the lens.

Brightness may only be made from a single point of greatest brightness.

You must use a full field white pattern for measurement.

If you get a single measurement which meets manufacturers claims, then they have sold you a 6,000 lumen projector.

Most projectors fall far short of that type of claim.
AV Integrated - Theater, whole house audio, and technology consultation during the build and installation process in the Washington, DC metropolitan area.
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Joined: Jun 25, 2017
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Thank you for this reply, it calms me down