Daily Photo Journal

Day 1:  May 2, 2007

Today was our first day on the project.  We had to figure out how we were going to set up our things to get pictures of the popcorn.  Setting up the hot plate and positioning the camera wasn’t that hard.  Our trigger to set off the flashes was a photogate with a little pen laser.   The laser had a table top tri-pod.  Getting the laser to work and point right at the photogate was a difficult task.  By the end of the class, we had the photogate going off when we ran our hand through the laser. 

After we had the hot plate set up, we turned it on.  Our plan was to make sure that the popcorn would pop.  Also, we were going to try and get a rough time estimate for how long it took to pop.  The kernel did pop; however, it took about 10 minutes.  That was a slight problem, but we also didn’t wait for the hotplate to fully heat up before putting on the kernel. 

The biggest problem from today was batteries.  The laser pen ran out of batteries really quick.  Either we need a lot of extra batteries, or we needed to find a new laser.

Day 2: May 3, 2007

Today we found a rhythm for popping the popcorn.  Adding too much oil made popping the kernel take longer.  Adding too little oil burnt the kernel and it would not pop. Allowing only one drop of oil to drip from the spoon was enough oil to put in the washer.  The washer's center diameter was roughly a centimeter.  It wasn't too much bigger than the kernel, but there was still plenty of room to flip the kenrel. After figuring out how much oil to add, we had to guess the timing.  It took a long time to pop by just letting the kernel sit in the oil; however, if you let it sit in the oil on one side for about 15-30 seconds, and then flip it to the other side (it’s usually a golden brown color on the heated side), then the popcorn popped relatively fast. 

From this rhythm, we got several successful pictures.  We had a couple problems to fix.  One of our big problems was smoke setting of the flash unit.  The smoke would obstruct the laser beam, which triggered the photogate.    This resulted in a fair amount of pictures of just the kernel sitting on the hotplate.  A second problem we had was focusing.  On some of our pictures, the kernel was in focus and on others it wasn’t.  Figuring out if we should focus in front of or behind the kernel was tricky because the kernel did not always pop the same. 

Day 3:  May 4, 2007

Today we started collecting data to use in our conclusions.  In our data table, we included the size and shape of the kernel as well as how the kernel popped.  In other words, we were trying to see if a small kernel had a small pop and a big kernel has a big pop.  With our new routine for taking pictures—adding a drop of oil, adding the kernel, flipping the kernel, shutting off the lights, and then taking pictures—we were able to get a great amount of pictures today.

 The smoke was still a problem today; however, it was useful in a couple cases.  Because the smoke randomly set off the flash units, it would set off the flash units while the popcorn was popping.  This gave us accidental multiple exposures.  With this information, we tried to increase the sensitivity of our photogate.  The idea was that if it was more sensitive then the smoke would set it off more, so we would get multiple exposures on purpose.  This did not work, so we changed the photogate back to normal sensitivity. 

The problem with our multiple exposures was that they were over exposed.  We tried compensating for that by changing the aperture, but then the picture was too dark.  In the end, we went back to taking single exposure pictures. 

Day 4: May 9, 2007

Our group did not take any pictures today.  We already had a lot of pictures.  Our plan was to start taking multiple exposure pictures using a computer set up, so we could calculate the velocity of a kernel popping.  However, we couldn’t set up the computer today, so we had nothing to do.

Day 5:  May 10, 2007

During this longer class period, we set up the computer system.  This was a harder task than planned.  Getting all the wires and finding the correct spot to put them was a difficult number.  Then trying to get the interface box to respond to the photogate was even more problematic.  Everything we tried did not make the computer set up work.  We tried using a reversing cord with the photogate; we tried different wires from the flashes, but nothing was working.   We spent all class changing or finding wires.  Because of our challenges with the computer, we were not able to take any pictures today. 

Day 6: May 11, 2007

Our computer problems are fixed.  We replaced the computer, the laser, the interface box, and the photogate trying to figure out which one was messing up.  It was the photogate.  Without new equipment, the popcorn would interrupt the photogate, which resulted in a multiple exposure shot. 

Our next task was to figure out timing.  This was a guess and check game.  We had to figure out the delay time and the flash interval.  We ended up with the delay time being .02 milliseconds and the flash interval at 20 milliseconds.  This allowed us to get good multiple exposure picture of the kernel about to pop, in the middle of popping, and after popping. 

Once again, our big problem was smoke.  The smoke would continually set off the photogate causing the flashes to go off.  We had a bunch of pictures that were just the kernel sitting on the hotplate with smoke going through the laser.  We aren’t exactly sure how to fix that.

Day 7:  May 17, 2007

Today was a good day.  We figured out focusing and our smoke problem. We could not figure out how to continuously pop popcorn and not have smoke, so we just turned off the hotplate and turned on a fan to cool it off.  This allowed us to wipe off extra oil that was causing the smoke.  After it cooled off, we turned the hotplate back on and started taking more pictures.  We took beautiful double and triple exposure pictures.  To focus, we used a nail.  We held the nail on the washer—not in the hole or in front of it, but on the circle. This was a good place to focus because it was slightly in front of the kernel, so that the kernel was still in focus if it popped straight up or a little forward (we had some pops that popped towards the camera and were blurry, so this focusing spot fixed that).   This allowed us to have a better focus whether the kernel popped straight up, to the front or to the back a little.  We focused before each kernel. 

As for the smoke, we had the hotplate up too high.  We set the hotplate as high as it could go thinking that was the quickest way to pop the popcorn and the only way to get enough heat.  Instead, we turned the hotplate down to 5 or 5 ½.  This is about a medium to a medium-high setting on our hotplate. This prevented burning of the kernel and it didn’t create as much smoke.  The only difference with the lower heat is that we waited just a little bit longer before flipping the kernel over.  Before, we waited around 10-15 seconds before flipping the kernel, and now we waited around 30 seconds to flip the kernel. 

We didn’t really have any problems today.  Everything went smoothly.  The only thing that happened that could have been problematic was that some kernels popped really quickly.   We would flip them over and, before we had time to move our hands all the way, it would pop and the oil would hit us.  It was more shocking than painful. 

Day 8:  May 18, 2008

Today was another good day.  Everything ran smoothly.  We kept the heat down and took some more pictures.  We did some other things that tied up loose ends.  Such as, we took some scale shots by holding a ruler in the same spot that we placed a kernel.  This gave us a scale to use for figuring out the velocity of the pops later. 

Also, another thing that happened today that was exciting was we took high speed video.  We were able to use the Motionscope, which is the high speed video camera, for half of the class period.  We took some really good footage of several kernels popping. 

We did not encounter any problems today. 

Day 9:  May 24, 2007

Today we worked on getting a few more photographs for the website.  We talked about how much we have left to do and who was doing what.  Today was more for organizing all of our stuff instead of strictly photographing.  We did get a few good pictures.