onto doesn't work at all for me, as it suggests movement. I don't think that's what you mean.
That native speakers don't always agree.What is our final conclusion?
You have asked a similar question before.So you disagree with the posters above? What is our final conclusion? Can anybody help?
Another way of looking at it is that 5jj and I are right. :-D
But seriously, why do you want to say onto? Are you trying to make it clear that the torch is moving from another focus position?
The thing is, if onto is wrong, then into is wrong as well.
And I have already used the 'shone the torch into the room' many times since Tarheel told me it's ok to use either on or onto. So before undertaking the tedious task of going back and replacing it, I need to know for sure whether 'shine into/onto' are acceptable forms or not.
Another way of looking at it is that 5jj and I are right. :-D