Originally Posted by damien55
Here is a summary of my setup:
- Projector: JVC HD350 installed 2.36m from the screen (minimum zoom and fully open Iris to get maximum brightness)
- Screen: DIY Fixed frame with white ORAY PVC screen material (gain 1 assumed as I can't find the datasheet) 1.75 m x 0.98 m = 5.74 feet x 3.21 feet
Here is a summary of my measurements with the new bulb:
- 20.86 ftL at 6587 K
Could someone tell me what it is equivalent to in term of Lumens? I think it gives 386.80 Lumens but I am unsure
The Projector central calculator tells me that I should be getting 54 ftL for this setup based on the manufacturers 1000 Lumens figure. I do not believe that the HD350 gives that much at 6500K but I should be getting more than 386 with a brand new bulb no? If I start at 386 with a new bulb then what will I get after 500 hours?
380 lumens in your setup = 20.8 fL is correct (or close enough). Are you buying the lamps from a generic supplier or a trusted source?
These numbers do not make much sense as far as how bright it should be. What type of device are you using to measure this?
Remember calibration devices do not provide accurate fL or accurate lumen measurements in general, you need a light meter instead (you can get them under $30 on Amazon).
That is a really small screen if you gave us correct measurements, I'll round up and call it 80".
With the IRIS clamped down, I would eastimate you would get 15 fL to 20+ fL MINIMUM.
With the IRIS open, even in low lamp you should be getting 25 fL to 30 fL.
In Lamp High, you should be getting well over 35 fL to 40 fL.
And I am estimating on the low side of those numbers above, it should generally be 10% to 20% higher than that even.
There could be some variances due to external factors, but I wouldn't expect you'd get much dimmer on a new lamp, that'd be unusual at best. You could get a high as 45-50 fL in some modes, but only the brightest uncalibrated mode. PJC often uses dynamic modes or near-brightest modes for their lumens baseline, so you cannot trust any data from that.