Originally Posted by Shepardos
Here an second update of my VW95 and light output:
Measurement was taken with an LUX meter in the middle of the screen. My screen is 2m wide and the throw distance is around 4m! I calibrated the VW95 to D65! ...
High Mode: 380 lux * 2.25 = 855 lumen!!!
Low Mode: 250 lux * 2.25 = 563 lumen!!
Hope this helps in terms the light output of the VW95...
Shepardos - thank you so much for posting this! This looks VERY encouraging. However, given that it is the highest lumen numbers we have seen posted yet, I have some questions to further clarify things:
1) Converting your numbers to inches, you have a 79 inch wide x 45 inch high screen (91 inch diagonal). Yes?
2) By my calculation, at a throw of 13 feet you are near the far range of the throw distance - about 80% back (with 100% back being the furthest throw distance). Yes?
3) You took these measurements with your projector calibrated to D65 and displayed a 100% full field pattern (or did you display a window, which could make a difference)? And you are 100% certain that at 100% you are calibrated to D65 within a dE of 3 or less, yes?
4) You stood at the screen, with your light meter placed up against the screen and pointed into the lens and measured 250 lux, yes? What light meter did you use? Is it a handheld light meter designed for this purpose or a meter used to do calibration?
5) In your calculation you multiplied the lux by 2.25. I assume this is the pre-calculated constant you have for converting lux to lumens and is accurate according to my calculations. I just want to point out to others that this is a function of his screen size and that others cannot use this multiplier unless they have the same screen size.
6) What type of screen and gain are you getting (just curious)?
OK so by my calculation I also get your lumens at 573. This is terrific!
However I wonder why it is SIGNIFICANTLY higher than what others have reported here. It is beyond reasonable bulb tolerances and also beyond typical measurement error or meter differences.
As an example, Kraine got about 100 less lumens than you and he was also very near the shortest throw which should be about 20% brighter than the throw you are at.
I am curious what you and others make of this difference.
In my case my throw is a little longer than yours. To be conservative I took off another 10% from your lumens to account for this difference throw. Even after this I would be getting 20ftL and would be DELIGHTED with that. Comparatively I would be at 14-15ftL if I go by Kraine's numbers, also adjusted for my throw. Certainly I'd prefer 20!
Bottom line is that we need more lumen reports so we can start to paint a picture and get some nice averages at both shortest and longest throw. Hopefully those folks getting their pj today and over the coming days will chime in!