My gut tells me it will not burn a hole at ten feet, the fact you left it open leads me to believe that if a 90 degree and a 5 degree will behave the same which seems doubtful. A gel with a low transmition rate will last for a show or two so I would assume photo copy paper, assuming the cheap lightweight stuff, would last roughly the same, if not a little shorter. Yet on the other side of the lens the light is hot enough to heat metal enough to make it expander and distort so it might be a toss-up.
Stick some paper in the gate and see how long it lasts
I don't think it'll burn anything at 10 feet. I've stood a few feet from one shining directly at me for a few minutes while focusing something else, and I didn't burn up.
Now here's the question Ship, would that be a high output or long life lamp?
A 750w high output 115v lamp behind a 5 degree lens might do it, although the narrowest S4 lens I have access to is a 10 degree so I wouldn't be able to test. But something tells me it still might not happen.
In some of the early revisions of the 26˚ and 36˚ lenses for the S4 (we are now at "revision G" I believe) it was possible to instantly burn anything in the color frame slots at certain barrel positions. With the 36˚ if the barrel was all the way in it would burn almost anything. I don't know what the position was on the 26˚, but there was an afternoon where I went to replace a color in one of our box boom positions and as soon as I dropped the new cut in it had a hole burned through the center.
As for burning paper, I think you would have to try pretty hard. I have managed to scorch wood with the lens tube not in the fixture and the end of the barrel housing about 3 inches from the wood, but I have seen people leave units on standing on the lens on the floor and not leave a mark. As much as I would like to try this, my lights are in use at the moment.
I believe that the light refocuses to a point within a foot or two of the lens depending on the beam spread. If you hit that focal point you'll get some serious fire. 10 feet away I doubt it.
This question is a lot easier with Altman 360's. If it's a 6X9 put the paper 9 inches from the lens and give it about 30 seconds. If it's a 6X12 then try it a 12 inches. 6X16...
In college we had these ladders in the torm position. My partner and I had hung and circuited our 360's and left them hanging straight down as we worked our way around focusing. Some were patched together with other instruments. So while focusing an instrument higher up on the torm, a lower instrument hanging straight down was also on and pointing at the pipe below it right in it's focal length. We managed to set the paint on the pipe on fire that day in seconds. Our T.D. was not pleased.
Haha...this reminds me of a small, stupid and surprising story.
Last year we were focusing and since our pipes don't lower we use one of those drivable genie lifts. There is, or was, a little bit of insullation stuff on the cross bar when you get in it so you don't bump your head. A PAR64 at about 10 feet started to burn and melt that insulation stuff, which surprised me.
That's why I despise that pink foam stuff as scenic pieces in themselves--especially flying it out.