Measure ANSI Lumens - projector

[timbo343]

Really simple question, is there a way to measure the brightness of a bulb/projector? We are getting reports that projectors are dim and the only way to test them is with another bulb.

[pcstru]

Do you have a light meter you can use in incident mode that will measure lux? If so ....

 

Personally I'd just eyeball it. It should be fairly obvious if the projector is fit for purpose or not.

Edited September 29, 2014 by pcstru

[timbo343]

Ive got a light meter app from the play store

[localzuk]

Get a light meter. £20 should get you one - Pocket Size Light Meter from Digital-Meters.com

 

Then just project a white image and see what it spits out. That number is a spot "lux" reading. To convert to lumens, you'd then you pop the number into this equation:

 

Φ_V(lm) = E_v(lx) × A_(m2₎

 

_{Or... Use this website - Lux to lumens (lm) conversion calculator}

[CamelMan]

Its can be subjective and we've been getting a lot of this lately - funny enough around those that have had a replacement recently.....

 

My stance is, if we think its too dim to teach then we pay for it, if not and the teacher still wants one then it comes out of their budget.

[timbo343]

Just reminded me, teachers leave the projectors whilst there isnt a class in and they are sat in their room (this is for another topic, possibly BTRD)

[synaesthesia]

Lux meters if someone has one - drama department maybe, or if you have a lighting technician handy...

 

Otherwise there's the manual method.

 

( WARNING - NOT SERIOUS! )

 

Look into the light.

 

"Bloody 'eck, I'm blind!". Bulb is in good working order and should see you through. Well not you, but maybe everyone else that hasn't been blinded.

"Ooer - someone fetch me sunglasses!" - Not bad. Should keep you going, keep an eye on the lamp counter though.

"A nice day in Hunstanton/Yarmouth/Skegness". Quite dim but acceptable to your or I. Perhaps would be fine in a poorly lit classroom.

"Eclipse". Not the maligned library system; you can see light around the edge of the lens but not much else. Time to get it changed pronto!

"Bloody 'eck, I'm blind!" Or are you? Is it on? Have you tried turning it off, then on again? Any explosions when power is applied? Does it rattle like a pair of maracas? Probably time to get that changed.