Difference between revisions of Optics related math
m →From blur horizon of naked eye: typos |
m →From blur horizon of naked eye: fix signs |
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For full correction, that's easy : <math>s=\infty</math> and so <math>f=s'</math>. Eg if your | For full correction, that's easy : <math>s=\infty</math> and so <math>f=s'</math>. Eg if your | ||
blur horizon is 20cm you need a 5D correction. | blur horizon is 20cm you need a -5D correction. | ||
For differentials to use a screen at, say, 50cm, just use <math>\frac{1}{f} = \frac{1}{0.50} + -\frac{1}{0.20} = -3D</math>. | For differentials to use a screen at, say, 50cm, just use <math>\frac{1}{f} = \frac{1}{0.50} + -\frac{1}{0.20} = -3D</math>. | ||
(Which is consistent with the previous version, subtracting 2D from the full correction of 5D.) | (Which is consistent with the previous version, subtracting 2D from the full correction of -5D.) | ||
==Point of refraction== | ==Point of refraction== | ||