High School Science Fair

Discussion in 'Casual Photo Conversations' started by carol_lee|2, Aug 30, 2011.

  1. Hello, I have been trying to figure out what to do for my High School Science Fair. I am fairly set on The Effect of Shutter Speed on Sports Photography Photo Clarity Rating and Brightness. What I would do is set my shutter speed at 9 different speeds: 1/4000, 1/2000, 1/1000, 1/500, 1/250, 1/125, 1/60, 1/30, and 1/15; then take photos of different sports all at those shutter speeds. And after I print the photos out i get survey 20 people to put the photos in the order of blurriest to clearest, and darkest to brightest. But I was thinking about adding aperture into it as a factor as well. Would adding it be too confusing and messy? or would it work better? Or should I just do one sport instead of a couple?
    Thanks, Carol
  2. stp


    In most science experiments, including yours, it's best to control the number of variables at work, and test for one variable at a time. My advice: do one sport, and have each shot look as much as possible like all of the other shots except for one variable. I think the variable you are most interested in is shutter speed. You would adjust the aperture for each shutter speed so that the exposure (brightness) is the same in all photos. You will end up with a series of photos that differ in only one regard: shutter speed. As a result, the effects of motion will appear different in all. The question is, what do you want to do after you have this series of pictures? Yes, people can put these in order from blurriest to clearest, but what does this tell you? Are you simply wanting to measure people's ability to detect blurriness (or clarity)? If so, your experiment is over after you've collected the data. Another possibility is to put them in order of shutter speed yourself and ask people to pick their favorite. Here you would be measuring the subjective preference of people for a certain kind of sports photography.
    A couple of suggestions: 1) there may not be a lot of difference between 1/4000, 1/2000, 1/1000, and 1/500 (depending on the sport you choose to photograph). You should run a test first to determine how many different shutter speeds you really need. The fewest possible would be best. You may want to add some slower shutter speeds (e.g., 1/8, 1/4, 1/2). Again, some preliminary tests would be useful. 2) You may want to control the sports activity so that the photos are as similar as possible except for the effect of shutter speed. Instead of going to a track meet or football game, you may want to set up a controlled condition and photograph that at varying shutter speeds. For example, you could set up a batter swinging a baseball bat, or a golfer swinging at a golf ball, or a hurdler jumping over a hurdle, or.... The hard part (IMO) will be to hit the shutter button at the same moment (or close to it) in each shot -- imagine trying to trip the shutter at the precise moment a golfer hits the ball on 100 shots. You might look into mechanical/electrical ways to fire the shutter that will have consistent timing of each shot. That way, you're controlling additional variables so that only one variable (shutter speed) is showing up in each photograph.
    I hope this helps.
  3. Carol, as a teacher with 30 years experience (mostly science) I've worked with and set up numerous science fairs. You may discover that as you research your problem that you may find that others ahead of you may have answered your question. Judges look for projects that follow the scientific method of problem solving. If you discover that what you're looking for is already known you might modify your original topic if needed.
    BTW, I think it's great that you are doing a photography related science project.
  4. So do you have any suggestions of what I could do then?
  5. stp


    I don't think Mike is saying any of the questions I suggested or any of the questions you may pose have already been answered. Frankly, I wouldn't worry about absolute originality as I would about setting up a well-designed experiment.
    My PhD dissertation was on the effects of urbanization on bird communities in Seattle, Washington. Two very similar studies had been done in eastern states. My study was the first west of the Mississippi (hence a different environment), some of the elements that I measured were different, and I asked a few additional questions. But I would not describe my study as original. The same fundamental question can be asked in different ways, and each sheds a different light on the issue.
    In addition, if you do a study on preferences, that's something that changes over time, and it may vary depending on age, gender, income, or other factors. I would concentrate more on coming up with an interesting question and well-designed experiment to address that question than spending time trying to be completely original.
  6. +1 to Stephen's comments, especially about choice of question, good experimental design, and not trying to be completely original, especially when you are just starting up the rungs of the scientific ladder. Not to brag, but just for reference, I'm a physicist with 40 yrs experience and am a full professor at a major university. For the past decade, I have reviewed around 50 senior (undergrad) projects per year, every year.
    Tom M
  7. Lots of good advice here. It seems this sort of question draws the academics come out of the woodwork, eh? (I'm one too -- sensory physiologist -- at least I used to be.)
    I personally feel there's great value to originality, even at the level of a science fair. However, I think I'm a bit "different" in this regard. When I was judging science fairs, I would give high marks for originality, while most other judges would seem to give high marks for "gee whiz." I think we all recognized, appreciated, and scored highly for solid experimental design.
    When my stepson was in high school, I helped him do a study of driver distraction from music and cell phone activity. (Texting hadn't been invented yet.) He found that even "voice-dialing" a phone number (i.e. using voice recognition) severely impaired a driver's response time in an emergency braking situation. I was proud of him, because he did something original, and his results were actually important and useful. It was a few years before all the studies started rolling out that established essentially the same thing. Although the judges didn't really appreciate his work, in relation to the more "gee whiz" projects, I think he got a lot out of the experience. Everytime cell phone hazards are mentioned, we all sort of nod to each other and say, "Yeah, we already knew that."
    I agree with others that you should try to minimize variables and that you should do some preliminary work to identify the variables and range of values you would like to explore. This would be called a "pilot study."
    I would offer the following thoughts about your questions:
    "How fast is fast enough to freeze motion?": I know what shutter speeds I use to freeze action in my own work, to suit my own tastes, but I frankly don't know how others view action photos. How critical is the average person's eye? I don't know that anyone has the answers, so I THINK this might be an original question. I will only add that starkly frozen motion (e.g. with a really fast flash) can look rather odd. For instance, a baseball might appear as "stuck" to the end of a bat being held by a statue. I don't know whether there might be an aesthetic value to a certain amount of motion blur in the photo. By way of example, please consider this experimental photo of mine:
    It was taken at 1/30 sec. I'm not saying blur is good or bad, but simply that it might be worth weighing this aesthetic as you formulate your project. For instance, asking "Which is best?" might yield a different result from "Which is sharpest?"
    Shutter speed and image brightness: Completely unoriginal. As exposure time decreases, your exposure will decrease (become darker) accordingly. You can find this in any photography book, and many or most of the judges will already know the answer, too. I wouldn't address this question.
    Finally, the critical shutter speed (fast enough) might vary according to:
    -- sporting event (e.g. freezing a baseball bat, vs. freezing a runner's feet vs. freezing an ice scater gliding along the ice)
    -- how much of the camera frame the athlete occupies (e.g. a field full of soccer players, vs. a closeup of a single soccer player). You may find that viewers demand less freezing of motion for the former than for the latter. I don't KNOW this, but I SUSPECT it.
    Whether these should be experimental variables (variables you manipulate in order to address/answer these questions) or nuisance variables (variables you hold constant), you should at least be aware of them.
    I, too, would suggest you minimize variables and limit the scope of your project. Variables can easily get out of hand. Personally, I'd treat everything but shutter speed as a nuisance variable and hold it constant. Your shutter speed then becomes your only independent variable. It's relatively easy to have multiple dependent variables if you wish. For instance, you can ask the same 20 people multiple questions: On a scale of 1-10, how sharp is this photo? How much do you like it? How fast do you feel this person running? Etc. Differences in the answers could be interesting and could give you something interesting to discuss.
  8. It depends on the local requirements but look closely at the requirements for doing experiments versus demonstrations, models, etc. A simpler experiment done well may be easier to accomplish than one with a more complex set of procedures. I had the opportunity to judge a couple of times and my daughters were serious competitors through the elementary school competitions. there was less emphasis when they got to junior and senior high school.
    I liked to see that the students were familiar with the science involved in their experiments (did the research!), understood the concept of controlling the variables, and understood what the experiment showed, or if it didn't support their hypothesis, if they could discuss what happened and why. I also liked those who had an idea of where they might go in future experiments if they were to follow up on the same topic. That might be as simple at the elementary level of asking what they liked, what they might do differently "next time," or if they found something in the research or results that they wanted to do more with. (One student continued a series of studies/experiments on a local watershed that by the time he reached high school, he was receiving national level recognition.)
    One thing I would suggest that if addressing the effects of shutter speed, that one must also vary aperture, otherwise a range of shutter speed changes would run from very underexposed to very overexposed. In this case, the exposure value remains constant. The motion effects would show the same as if the aperture wasn't varied as well but depending on the range, might not be easily seen.
    As to some of the other issues, remember the set up needs to be repeatable (research into the basic issue should suggest movements or motions that might work and test early to allow for restructuring if you need to to get more obvious or interesting results). I'd also suggest that the measurements/results be objective, not subjective. Objective results are the subject moved .25" across the print at speed 1, .5" across the print in speed 2, etc. Asking which image a variety of people "like" could yield wildly varying results.
  9. Carol:
    Which shutter speed do you expect to be the sharpest? Which one will be the brightest?
    I'm not really sure this makes for a good science fair project. It seems rather obvious what the outcome will be. This is more of a demonstration than a project.
  10. What about using digital still photography to analyze motion? You could use continous as well as blinking light sources (about 2 Hz works well) attached to moving objects and do some time exposures. My youngest son did a project similar to this a few years ago. For example, you could show traffic flow with time exposures and the headlamps and tail lights would provide the evidence of motion. Attaching a blinking light to a vehicle would show steady speed by evenly spaced "dots" of light, whereas acceleration would show the dots progressivley more separated as the object accelerates. (The physics book I teach from calls that a particle model of motion.)

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