Tom_MS wrote:Optics (10): 6/10. The laser shoot here was perfectly good. In fact, they carried it out better than almost any other competition I've been to. For once, I have no qualms with the laser shoot. The test was kind of meh. They had put the questions in a blue folder in sheet protectors, with strict instructions not to write on it. This would have been fine, but the sheet protectors were bound in the same order, so it was hard to efficiently split up the test or review your partner's answers. I found the test quite odd compared to last year. It was of course written by different test writers than last year, and you could tell. The first two thirds consisted of a mix of easy multiple choice, weird ray tracing, and an oddly worded question about floor mirrors (if you took it, you know what I mean). The last third consisted of out of place trivia questions and really easy absorption and reflection spectra questions. So essentially, the differentiating factor for top teams was probably the laser shoot and the weird ray tracing.
Now, only read this rant if you actually do optics. Ray tracing is normal. You always expect ray tracing. Maybe even two lens system ray tracing. Maybe even lens and mirror ray tracing (I've only seen it a couple times). But this seemed like poorly designed ray tracing. First of all, there was a disproportionate emphasis on it. About 4 questions required that you do it, and if I'm remembering correctly, 3 were 2-lens systems. Second of all, the answers were weird. According to ray tracing as well as math (unless we were doing both wrong, which is possible), some of the final images ended up inside lenses in the system. A correction had to be made as to the positioning of focal points in a diagram because their positioning was asymmetric. The final image ended up right next the intermediate image of some systems, making ray tracing messy and difficult. Maybe there is another method of two-lens system ray tracing that we don't get, but it felt really weird.
Im glad you enjoyed the laser shoot! I did not build it, but I ran it for you guys and really enjoyed seeing the way you approached it. It was definitely interesting to see how many of the teams in the top 6 used pretty different methods on the laser shoot, but nearly all in the top 6 did 5 mirrors + 1 barrier mirror. I will say the test was written by an ES who was not able to attend Nationals in the end and the ES doing the grading was very fair in how he approached grading the ray tracing and was pretty lenient with it, making sure to take into account the teams' intent and giving partial credit as such. Despite all accounts on here about how the test was not hard enough, it actually did do a pretty good job separating teams and the margins within the top 6 were wide enough IMO.