I'm trying to see if there is much of a difference in brightness of the Panny AE1000U and the Epson PowerLite Home Cinema 1080 Projector. But as I already have my wiring in both will be 13' from the 100" screen. As the zoom range starts much closer on the Epson at 8.4 ft I actually loose a lot more brightness compared to the Panny which starts it's range at 11.5'. Here is how I did the calculation. Did I do it correctly?

I did a calculation based on the highest brightness setting of both but then reduced each for the distance of my screen to the projector which is set at 13'. Both projectors lenses reduce the max brightness by 45% when using the maximum throw of the zoom (All values came from Projector Centrals reviews). But as the Panny range is 11.5' to 19.7 and the Epson is 8.4 to 14.7 I actually have to zoom more with the Epson than the Panny and thus it should greatly reduce the light output of the Epson for the same physical throw distance. In the end I get 826 Lumens for the Panny and 867 for the Epson. So it would seem if you calibrated them similarly you would get the nearly same brightness for any setting at 13'.

Do you agree?
Here's my formula
Lumen at 13' = Brightest Lumen - Reduction for amount of zoom used

= Brightest Lumen - Brightest Lumen(.45(reduction for either in full zoom))(Percentage of zoom used)

So for the Panny it's 900-900(.45)((13'-11.5')/(19.7'-11.5'))=826 Lumens @13'
for the Epson it's 1292-1292(.45)((13'-8.4)/(14.7-8.4)) = 867 Lumens @13'

According to the calculator at Projector Central

Mounted at 13 feet from a 100 inch screen with a 1.0 screen gain:
AE1000U = 14fL
PC1080 = 15fL

Looks about even to me. From what I am reading today, the argument is not over the brightness, it's over reliability and inclusion of the newest technologies.

The pjc fL numbers are never accurate, if you look carefuly it never changes as you slide the projector closer or farther from the screen. Never use those to calculate lumens for your setup or for comparisons.

Both in brightest modes they measured the Panny at 900 lumens and the Epson at 1292 lumens, making the Epson 43% brighter than the Panny. That doesn't compute when you use the calculators fL.

For the OP, check your range nbrs, they seem to be off. You have the Panny in your calc at 11.5 -19.7, but it should be 9.7 instead of 11.5.

Panny (http://www.projectorcentral.com/Panasonic_Home-PT-AE1000U-projection-calculator-pro.htm) has a 2.0:1 lens
range for a 100" screen is 9.7' to 19.6'
at 13ft for 100" screen your lens is at 1.51:1

Epson (http://www.projectorcentral.com/Epson-PowerLite_Home_Cinema_1080-projection-calculator-pro.htm) has a 2.1:1 lens
range for a 100" screen is 9.8' to 20.9'
at 13ft for a 100" screen your lens is at 1.59:1


hope this helps
Joe

You should read the Projector Reviews review of each projector. Read the section on brightness

Epson
http://www.projectorreviews.com/epson/HomeProCinema1080/performance.asp

Panasonic
http://www.projectorreviews.com/panasonic/PTAE1000U/performance.asp

The pjc fL numbers are never accurate, if you look carefuly it never changes as you slide the projector closer or farther from the screen. Never use those to calculate lumens for your setup or for comparisons.

Both in brightest modes they measured the Panny at 900 lumens and the Epson at 1292 lumens, making the Epson 43% brighter than the Panny. That doesn't compute when you use the calculators fL.

For the OP, check your range nbrs, they seem to be off. You have the Panny in your calc at 11.5 -19.7, but it should be 9.7 instead of 11.5.

Panny (http://www.projectorcentral.com/Panasonic_Home-PT-AE1000U-projection-calculator-pro.htm) has a 2.0:1 lens
range for a 100" screen is 9.7' to 19.6'
at 13ft for 100" screen your lens is at 1.51:1

Epson (http://www.projectorcentral.com/Epson-PowerLite_Home_Cinema_1080-projection-calculator-pro.htm) has a 2.1:1 lens
range for a 100" screen is 9.8' to 20.9'
at 13ft for a 100" screen your lens is at 1.59:1


hope this helps
Joe

Joe
Where did you get the 9.7' number from?

I got this off the Panasonic press release and it has a 5' distance for a 100" screen mentioned. But on the Projector Central data sheet (if you look up the specs on there site) it does say 11.5 to 19. 6 but dos not give a screen size. Panny specs from Projector Central (http://www.projectorcentral.com/Panasonic_Home-PT-AE1000U.htm)

"Thanks to both features, the new model can cast a 100-inch diagonal image from as little as 1.24 meters (about five feet) from the screen."
Panasonic press release (http://www.projectorcentral.com/news_story_956.htm)

Joe
Where did you get the 9.7' number from?

I got this off the Panasonic press release and it has a 5' distance for a 100" screen mentioned. But on the Projector Central data sheet (if you look up the specs on there site) it does say 11.5 to 19. 6 but dos not give a screen size. Panny specs from Projector Central (http://www.projectorcentral.com/Panasonic_Home-PT-AE1000U.htm)

"Thanks to both features, the new model can cast a 100-inch diagonal image from as little as 1.24 meters (about five feet) from the screen."
Panasonic press release (http://www.projectorcentral.com/news_story_956.htm)

click the 2 links I provided in my post, go down the 2 from the bottom right hand side box, click the + or - until it says 100" diagonal and check read the distance range slider at top left.

You should read the Projector Reviews review of each projector. Read the section on brightness

Epson
http://www.projectorreviews.com/epson/HomeProCinema1080/performance.asp

Panasonic
http://www.projectorreviews.com/panasonic/PTAE1000U/performance.asp

Wow great reviews and right on my questions. I also like that he did some standardized testing with a 100" screen. I think for me the Epson is the way to go. I don't need the extra inputs and I can get to the bottom as my projector is dropped down from the ceiling.

I can say for sure that the Epson will be noticeably brighter than the Panasonic. I demoed both of them (Epson ProCinema 1080 vs. Panny AE1000) side by side in a dedicated room with no ambient light. Each was projecting on their own dedicated screen simultaneously side by side. The Epson was noticeably brighter and in my opinion a clear winner with all types of content both SD and HD. The AE1000U just looked washed out next to the Epson.

Cheers!
JD

Well I bought the Epson as the brightness is my most important need. With the new HDMI 4X2 HDMI receiver I'm buying in August I really only will need one HDMI input. Thanks for finding me those reviews Joe Black as I have never been to that site.