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Photo Journal

Session 1, 2/11/2003, 4-5:30 PM

During this session we planned the project and possible variations in our experiment.  We found an appropriate fishtank, which we cleaned, and a room in which to take photographs.  We attempted a completely underwater balloon burst to determine how sensitive of a sound trigger we would need.  We would not need a very sensitive sound trigger.  We decided to use a mop to clean up spilled water and came up with a method to minimize spills.  We placed the top of the tank on while bursting the balloon.

We found that the balloon puts up a large amount of resistance to being pushed underwater, and we will attempt less strenuous methods of submersion in the next session.

Session 2, 2/16/2003, 1-4PM

The tank and water are highly reflective, so to eliminate this problem we placed black cloth over all reflective surfaces in photograph window, including the photographer.  We scrubbed the inside the tank to eliminate air bubbles, and switched from batteries to pug-ins for out flash and camera due to the weakness of our batteries.

We attempted to weigh down the balloon with a brick, but the balloon simply elongated.  We added a cement block without better results.  The brick did make it easier to push the balloon underwater, however.  

We changed back to batteries for the flash unit at this point because the burst wets it.  Leaving the unit plugged in is a safety hazard.  We put a clear plastic bag over the flash unit to protect it from the water.

We cleaned the fishtank again because it was full of plantlike debris.  After cleaning the fishtank, we decided to use the deep specially made plastic tank instead, as it has better optical qualities and does not have the lining of scum like the fishtank.

A balloon exploded against Dexter's arm while being pushed in the tank, so we're filling them with less air now.

We took four relatively successful photographs of balloons halfway submerged.  Following is the data for those first four shots:

The chart above reveals we found that f-stop of 10 resulted in a badly underexposed photograph, while the following photographs, taken with an f-stop of 5.1, with the flash half a meter closer, turned out fairly well exposed.  Our shutter speed of "bulb" did result in some thermal noise in the photographs, which has been edited out in the pictures on this website.  The focus in all our pictures seemed acceptable.  We moved the sound trigger to capture different moments in a balloon burst, the closest ones being directly above the tank, and the longer time being further away and to the side of the tank. 

Our final picture, frame 5, was a completely underwater shot of a balloon burst.  Unfortunately, due to nature of the splash coming a short time period after the burst itself, the photograph only recorded the splash.  Therefore, to take completely underwater shots, we may need an more sensitive sound trigger.  First we will try different placements for the trigger, such a directly to one side of the balloon, just outside the tank, to see if this will solve our problem.

Session 3, 2/18/03, 4-5PM

Today we will attempt photographing balloons being burst by pin prick when they are completely underwater.  All the photographs taken today are problematic because they tend to be the form of the balloon in bubbles without any actual ripping balloon visible.  We also ran across many mechanical problems with out sound trigger today and tried several different setups, none of which worked, in attempt to capture a balloon bursting underwater.

We had mechanical difficulty with our sound trigger used in previous sessions, so we have replaced it with a more sensitive sound trigger.  The balloons are popping prematurely, so Dexter put a piece of tape over the hole he pops the balloon through to make it harder to pop them by accident.  We adjusted the sensitivity of the sound trigger as we go.  Although we thought we had the sound trigger right, our pictures still did not seem to be coming out well.  We also adjusted the air pressure in the balloon to see if this would help solve the problem.  

Here is an example of the kinds of pictures we were getting:

After this picture, the third of the day, we adjusted the sound trigger again due to the air bubble only problem.  For frame 9 the sound trigger is dialed as sensitive as possible.  Now we are getting multiple flashes for each picture.  To solve this problem we hooked a delay unit to the sound trigger on minimum delay.  This prevents the flash going off in series.

Frame 11 -- We had the trigger as sensitive as possible with a minimum delay and got a completely black picture.  We have decided that to take photographs of completely underwater balloons was must change our method from pricking the balloons with a pin to shooting them with a gun.   

Session 4, 2/20/03, 3-4:30 PM

Today we began shooting completely underwater balloons with the pellet gun RWS Diana.  We have computerized the delay because timing is very critical and we must be able to make very small changes in the delay.  We ended up taking six successful photographs over the course of an hour and a half.

The first photograph, of a long orange balloon, seemed a little dark.  After some editing most of the balloon was visible, however, at this point we decided we needed more light.  So we added the mirror to the opposite side of the tank and lowered the f-stop from 7.3 to 6.1.  On the second photograph the balloon was still too dark, so we lowered the f-stop again from 6.1 to 5.0 for the next shot, where it remained for the rest of the experiment.

The third photograph was also an orange long balloon with the bottom too dark.  This was due to the fact the balloon was so long and the flash was aimed at the top end of it.  From then on, we used only spherical balloons. 

The third photograph:

The fourth photograph, of a dark red spherical balloon, seemed quite dark even though no settings were changed.  The following two photographs seemed to have adequate exposure, although it would not have hurt if they had been brighter.

The fifth photograph:

Since we have not seen the pellet or anything except the ends of the balloon splitting at any point during our experiment today, we came to the conclusion that the pellet must be entering the top back of the balloon.  In our next session, we plan to arrange the balloon so that the pellet enters the front of the balloon, perhaps enabling us to capture the balloon actual splitting.

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