I need to get an illuminated magnifier for some scroll work. I can't see
the blade and line.

I was noticing that there are 3,5 and 11 diopter lenses.

A 5 diopter winds up being a magnification of 2.25 5 * 1/4 +1

So the question is, what should I get? Is 5 too powerful, is 3 to little.
Is 11 necessary?

Would like to get one today to get some Christmas work done.