Optics B/C

[physicsphan]

So, at least in C, while the line must be drawn to where the laser will hit on the wall, that is not necessarily where the target will be. A bit of an unorthodox move on the part of the state, but from what the rules say it sounds perfectly legal.

Does that make sense?


Yes, thank you. I had not read this anywhere in the rules about how they could move the target and when we tried to adjust our setup in 4 minutes..... we were about 36 cm off due to the rush and ended up not doing so well. But this does help. Thanks again.

I think this is probably why they have posted the most recent FAQ on the national website to make this point more clear.

[Infinity Flat]

At nationals I would count on the Target Point NOT being on the center line, for C division at least.

[chalker]

So, at least in C, while the line must be drawn to where the laser will hit on the wall, that is not necessarily where the target will be. A bit of an unorthodox move on the part of the state, but from what the rules say it sounds perfectly legal.

Note in BOTH B and C division the target can be anywhere on the far wall. I'm surprised by how many people missed this in the rules. Based upon what I've heard, more often than not event supervisors are putting the target somewhere other than the midpoint of the far wall.

[49ers]

Does anyone happen to know what the smallest diameter of the pupil? it was a question on one of the practice tests NEOawesomness and I were taking, and there was no answer key. Thanks.

[foreverphysics]

About 3 mm, from what I know.
(Note that this may or may not be accurate; I've only read that clinician's optics book once.)

[49ers]

alright I read one source that said .5mm but I don't know. i will keep looking but i have to leave.

[Seracon]

alright I read one source that said .5mm but I don't know. i will keep looking but i have to leave.

I have 3-5mm for smallest pupil size in my notes.

[SciBomb97]

alright I read one source that said .5mm but I don't know. i will keep looking but i have to leave.

With a pupil size that small, you'd probably see a blur due to the diffraction around the pupil edge. Large amoeba are about .5mm big. 3mm sounds right.

[chalker]

alright I read one source that said .5mm but I don't know. i will keep looking but i have to leave.

With a pupil size that small, you'd probably see a blur due to the diffraction around the pupil edge. Large amoeba are about .5mm big. 3mm sounds right.

.5mm is off by a factor of 10: http://en.wikipedia.org/wiki/Pupil

[49ers]

Alright thank you for the quick responses. Another question I happen to have is what number of rod cells and cone cells are normal? I received a variety of answers from the internet, and i lack a textbook.
*EDIT: I forgot to also ask about the blind spot of an eye, what would the field of view size of it be?