You can scale all you want. The point was only about where in the stack it happens. We used to do it with a Freznel lens out in the air in front of the tv, and

You can scale all you want. The point was only about where in the stack it happens. We used to do it with a Freznel lens out in the air in front of the tv, and we don't do it that way any more either. You could make a cup of coffee by first boiling some water, and then keeping it hot while you grow and harvest the coffee, and eventually finally combine the water with the grounds. If someone comes along and says that is a terrible way to get the job done, they are not saying you can't have hot water or coffee.