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Church and H.O.W. Forums for HOW Sound and AV - Your Displayed Name Must Be Your Real Full Name To Post In The Church and HOW Forums => H.O.W. AV => Topic started by: Stephen Swaffer on February 03, 2016, 01:18:19 pm

Title: Practically speaking how do projector specs interact?
Post by: Stephen Swaffer on February 03, 2016, 01:18:19 pm
I am looking at a replacement projector for our auditorium.  The challenge we face is the auditorium was built in 1865 with large stained glass windows on the east and the west-so depending on time of day it can be tough, though we usually get by by killing some house lights.

Existing projector is 5500 lumens 600:1 contrast ratio, replacement I am looking at is 5000 lumens, 11000:1 contrast. Am I going backwards too far?

Thank you!
Title: Re: Practically speaking how do projector specs interact?
Post by: John L Nobile on February 03, 2016, 02:45:29 pm
Not sure what your budget is but we got this one last year and it looks great.

http://www.necdisplay.com/p/multimedia-projectors/np-pa621x



Title: Re: Practically speaking how do projector specs interact?
Post by: Jeff Carter on February 03, 2016, 08:09:57 pm
I am looking at a replacement projector for our auditorium.  The challenge we face is the auditorium was built in 1865 with large stained glass windows on the east and the west-so depending on time of day it can be tough, though we usually get by by killing some house lights.

Existing projector is 5500 lumens 600:1 contrast ratio, replacement I am looking at is 5000 lumens, 11000:1 contrast. Am I going backwards too far?

Thank you!

Contrast ratio is meaningless in any lighting situation other than "blackout" since the ambient light hitting the screen will be much brighter than any leakage from the projector. Take ambient light into account and you'll probably find your practical contrast ratio is something more in the 20:1 range or maybe even less.

The output of the projectors should be close (unless the 5500 has a brand new lamp I'd imagine the 5k would look brighter in a side-by-side test) but the lumen spec doesn't always give the whole story about how the image is going to look with your content (a bit like loudspeakers in that respect). No substitute for bringing in a demo if that's feasible.
Title: Practically speaking how do projector specs interact?
Post by: Jordan Wolf on February 04, 2016, 04:44:09 pm
Nothing beats the sun...

That being said, the higher the lumen output, you more of a difference there will be between ambient light and projected light.

Controlling ambient light is the key to projection. Maybe invest in custom automatic blackout shades with quiet motors  that can be raised and lowered as needed. Then, you just need to worry about the house and/or stage lighting.

There's also the option of LED walls, which may not be as cost-prohibitive as you think if a small pixel pitch is able to be compensated for due to viewing distance. A lower nit value can mean lower price, too.


- Jordan Wolf
Title: Re: Practically speaking how do projector specs interact?
Post by: Caleb Dueck on February 05, 2016, 07:01:03 pm
Shades, ambient light rejecting screens like DaLite Parallax, high lumen projectors like 8k+.  If none of those work, LED wall.  We installed a 3.9mm LED wall in a church recently that had significant windows, direct sunlight on the screen area, and just "burned through" the ambient light.