Well after squinting at lot of bulbs, there's really no way to tell by looking. But I think I have the solution:
Download one of the free photometer apps to your smartphone. Their accuracy is crap, but good enough for course comparisons.
As for me, i happened on a box of ten vintage Eveready Mazda 1116s for cheap. They are conveniently marked "TOP" on the base, so correct orientation is not a problem.
Download one of the free photometer apps to your smartphone. Their accuracy is crap, but good enough for course comparisons.
As for me, i happened on a box of ten vintage Eveready Mazda 1116s for cheap. They are conveniently marked "TOP" on the base, so correct orientation is not a problem.