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Forgive my ignorance, but what mechanism did they use to not damage their retinas by staring at the sun through a telescope?
by match 12y ago
Forgive my ignorance, but what mechanism did they use to not damage their retinas by staring at the sun through a telescope?
- ovi256 12y agoA dark filter of some kind ? Can be as simple as smoked glass. The ones manufactured for modern photography are called Neutral Density filters, and they're available in a variety of f-stops, but the intensity reduction is insufficient for observing the sun safely. Higher reduction filters are built for astronomy.
- fsk 12y agoI thought the way that sunspot counting works is that you point a magnifying telescope at the sun, and the image projects on the floor. You look at the image on the floor. He did have a valid point. For the data to be consistent across a 300+ year data set, he had to use the same method as his predecessors. However, you could use technology to augment the manual count. They could use the same k-factor adjustment they used to compare multiple human counters, and use the same k-factor adjustment when technology changes.