Brightness of Calibration

[argo]

Hello,

Setting up the brightness seems to be very difficult for me. and i dont think that should be this much hard and i totally believe this problem related to one of my hardwares(either webcam or projector). the calibration panel is precisely 90 degree and i am sure of it.
Below image shows what is wrong with my setup. in the middle channel there are some places that brightness are high. and other channels shows the brightness are even low.
how do you manage the brightness to be same at all parts?!

Regards,

[Lunat1c]

Hi again,

-I would intuitively choose the top right portion of this image as reference and I should say it's dark.
-There can be different bright areas and contrast differences on the calibration panel, because it has a depth and, since you're using positive corner, there is a reflection from wall to wall.

Best regards,

[argo]

Thank you Lunat1c for the help. I really appreciate that.

you are right that part is so dark but if want to increase the brightness, that will affect all other parts too. and there are some parts that already are too much bright.

this time for another test i nearly closed the diaphragm (iris aperture) and let the projector brightness (in both David and Projector) to be at maximum.
and the result came out much more better
I think i am going to change the lens again. i need to find a good 12mm one, not like this one which varies between 2.8 and 12!
and the idea of using negative corner sounds great and Walter also suggested it before.
but i have to find a way to work with this positive corner. and i love such these challenges

Good luck my friend.