I've had my screen up and running for a few months now. I'm really happy with the results. I do feel it's the best image I've been able to get out of my proudly dinosaur CRT so far.
I must give a big thank you too MississippiMan. I was asking about Torus screens here
. I was excited about old threads I'd come across about Torus screens, but due to lack of suitable fabric was about to give up on them until MMan convinced me it was still viable with an alternative approach. Which is what I've used here. Also with his recommendation I went with the MaxxMudd LL paint.
I've been meaning to put here a write up of how I did it for a while now complete with lots of pics. So here goes:
Firstly I should say that I used a RS-MaxxMudd LL formula in combination with the toroidal screen. I didn't have the energy or patience to do a proper experimental comparison where I first paint the screen, set it up flat, take screen shots, then go about creating the toroidal mounting and take more screenshots. It was a pretty big undertaking as it was. So I can't honestly say how much of the resulting image is attributable to the paint and how much to the curved screen. (Though if someone was to twist my arm I'd probably go in favour of the paint.)
I'll put up projected image screenshots soon in another post.
My final 16:9 screen size was 2.7m x 1.5m (106" x 60") - 121" diagonal.
I did use the torus calc spreadsheet provided by Pjackso here. The four corners stick out about 2.5" from the lowest point on the screen.
First up was making the paint. I'm in Melbourne Australia and the first challenge was sourcing local paints for the MaxMudd LL v2.1.
MMan said somewhere that the quantities in the recipe gave enough coverage for a 156" screen with some left for repeated touch ups. I adjusted the quantities for my 121" screen and that did save me having to buy a few extra cans of paint that I would have only half used.
That said I replaced the;
'Rustoleum Metallic Accents - White Pearl' with
Dulux 'Design' 'Pearl'
'Behr 1850 Ultra Pure White - Flat' with
Dulux 'Design' 'Silk'
(The guys at the paint desk in Bunnings was saying I shouldn't bother with the Dulux Design series Silk, but when we put it side by side with the standard Dulux white from which all the colours are made, it was clearly whiter and brighter.)
'Minwax Polycrylic - Satin finish' with
Cabots Cabothane Clear Water based Satin.
The Liquitex Silver was readily available at Eckersley.
All up I think I spent about $100 on the paints.
My wife turned out to be a better spray painter than me. She did a great job.
Also, I bought a $40 spray gun from Bunnings. An Ozito 300w spray gun. To my surprise it did a great job! As MMan has said many a time I believe it's all in correctly thinning the paint. Here's a close up showing the quality of the final finish.
Frame construction was pretty simple. Just a few support section on the back of the frame for added strength.
The sheet of Forex I bought was only 3mm thick. But it has still worked well enough. I lucked out finding a sign writer who had a big sheet of it that I think they just wanted to get rid of. I paid $50 for it, much better than anywhere else I called.
I cut eight angle sections of wood for attaching the screen and achieving the torus shape. (The four big corner ones pictured here.)
Initially I tried to do it all with the frame lying down. However as you can see I was getting a 'W' shape that was hard to get rid of.
I then had the idea of putting the frame up against the wall with two ends secured and letting gravity help me. This worked much better. There was a bit of going backwards and forwards. I had the screen up longways first, secured the bottom. Then rotated it 90deg and re-secured it. And went back the other way for some final tensioning adjustments.
(Also in this pic you can see the difference in colour between the original white of the Sintra(Forex) and the paint.)
I ended up taking out the four blocks that I had on the middle of each side. The screen had a natural curvature of it's own that was fighting against the shape those blocks was trying to coerce it into. The only downside I can say is that after the first week the curvature of the screen settled with a slight sag towards the bottom half. Not noticeable unless you walk right up to it and cast your eye along the side.
After my wife and I carried inside, it's largely free standing against the back wall. I only used a few small hooks and wire to secure it and make sure it doesn't topple over.
Here's some final pics of the resulting screen.
One of the largest enemies of a good screen image is light washing back onto the screen. Something I did on my previous screen was to put a light hood at the top of the screen. It comes out about 40cm (15") and makes a big difference in blocking light to and from the white ceiling. It doesn't stand out at all from the position of the couch.
Other measures I've taken to combat light wash is extending the light hood down the sides of the screen and merging with the speakers. I found a great big $40 carpet offcut to put down over the white tiles in front of the screen. Also very helpful.
I couldn't help but put in a pic of my projector hush box, which turned out to be a far more involved project. Though the result of which I very happy with.
I must say I'm very happy with the results. It took me a bit of tinkering re-adjusting my brightness and gamma settings to deal with the new paint. But satisfied I've got it good enough for my eye anyway.
Screen captures coming soon.