Thanks, I have still got a lot of processing issues to sort out, but am getting better.
I used this calculator to work out focal lengths and, pinhole size. https://www.mrpinhole.com/wiz.php
You can use paper but its ISO is about 1. I use normal film for 8x10 and xray film for 14x17. Xray film has a few processing issues (scratches very easily), but is relatively cheap bought in the USA on ebay (100 sheets for under $200 including gst Australian delivered to the door)
Like I tell everyone a camera is just a box with a lens up one end and a piece of photo film/ photo paper or digital sensor up the other end.....although a big box is really hard to make light tight.
I made mine to take 2 different lens one .7mm at 270mm focal length is around f350 gives a 90 degree view angle and full coverage of about 600mm on the diagonal. I made a box with in a box so I can use .8mm lens at 360m focal length and 75 view angle, doesnt quite cover the film, havent used it yet so not sure what the look would be.
I made a film holder, but cant stop the light leaks, so put film in the darkroom and keep it covered up and only get one shot.
There are heaps to do with pinhole, get into it. Large format is reasonably sharp at close quarters if you use the calculator for optimum sharpness. Heaps of info on the web, best cameras are ones you make yourself.