Today I finally built the masking for my screen. It should allow it to go anyway from 1.78:1 to 2.6:1. Aspects ratios less than 1.78:1 will still have black bars on the side. The work is partially based on the information I found in this thread
Original screen aspect ratio = 1.78:1
Diagonal = 130"
Width = 113.3"
Height = 63.7"
Masked to 2.35:1
Diagonal = 123.1
Width = 113.3
Height = 48.2
Masked to 2.4:1
Diagonal = 122.7
Width = 113.3
Height = 47.2
What I built was two panels to mask the top and bottom parts of the screen.
1x Rigid foam panel with silver siding on one side (4'x8') ($11.25)
Velcro 15 feet ($21)
3x8 foot J channel ($27)
Thumb Tacks ($1.30)
Already had tape , fabric.
I first cut 3 x 10" strips from the rigid foam panel. Since my projector is ceiling mounted , I cut the edge at a 30 degree angle to prevent the edge from casting a shadow on the screen.
The mask width is 118" so I had to use two pieces of the j-channel and the rigid foam and tape everything together.
I used thin velcro strips to attach to the GOM fabric.
To hang it I used the thumb tacks to attach velcro to the wood in the frames. Then I just attached the masking panels using velcro.
Adjusting it was fairly simple, I just play the movie and fine adjust the velcro.
Made a HUGE difference with contrast. I don't hate cinema scope any more.
Top panel is not even visible. Still have the cleanup.