Because it does not intersect the optical axis at the focal point. The distance labelled 'f' at the top indicates where the focal point is on the optical axis and only the bottom ray crosses it so the rule of the refracted light becoming parallel applies to it - hope it makes sense!
28:55 I thought there must be a small (infinite small? ) point of light in focus but there's a spot. Why?
9:40 the angle of the refracted wave has the wrong sing to it, oder ?
great basic tutorial. Very useful.
Nice Sir Fletcher.....good tutorial....I like your mobile microscope....CellScope...
Why isn't the upper green ray parallel to the focal plain, as previously explained?
Because it does not intersect the optical axis at the focal point. The distance labelled 'f' at the top indicates where the focal point is on the optical axis and only the bottom ray crosses it so the rule of the refracted light becoming parallel applies to it - hope it makes sense!
This was awesome! Love the experiments and detailed explanations
When using light microscopy, do you start from the largest or the smallest distance (between the lens and? The specimen)? Why
You start with Lowest magnification and hence largest working distance.
@@poodook ok , Thank u
Great tutorial
very good tutorial - thank you
great video!
Congratulations!
Very useful!! Thank you
Paul Rudd?
supergood
The optics you learn in high school physics, basically.
هسه انا شفتهم عود، 😂😂😂
I remember doing this as a school boy. Today it is university level education.
Please don't wave your hands--it is very distracting