Water Droplet Photography Continued

After yesterday's successful attempts at taking photos of droplets, I improved the set up slightly and took some more photos.

Wood scaffolding.

I used some balsa wood strips to create a simple structure for holding the drop detector and LEDs. I added a fourth LED module to increase the brightness of the flash.

Detector.

By putting the detector in a ring and properly shrouding the LED and photoresistor, I decreased the amount of light leaking from the detector and made the threshold value more consistent.

Exposure without the flash. Almost completely black now.

My dad also brought home a pipette so making drops is far easier now.

Pipette!

Okay, that's great and all, but how about the results?
The exposure was 1.6 seconds, f/5.6 (later f/6.3), ISO 400:

First shot.

A bit dark and slightly out of focus. Also, the photo don't seem as bright as my initial setup because the LED modules are not in frame. However, the additional module did brighten the actual point of interest. Some tweaking and bumping up the ISO to 800 got me this:

Nice.

Had to change the background to black and move the camera down so the axis of the lens was closer to parallel to the surface of the liquid to really see the drops in the air.

Separation.

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I also tested some strobing to catch different parts of the splash in one frame:

Trippy.

An interesting frame:

Huh.

The surface is partially illuminated, which leads me think that the flash turned on right at the end of the exposure as the mechanical shutter closed. The top of the frame is illuminated because the shutter closes from top to bottom, and the image projected on the sensor is inverted. You can see this happening in this video by the Slow Mo Guys. I'm not sure, but the lack of a distinct line where the shutter was when the light turned on might be from the rise time of the LEDs.

Or maybe I'm completely wrong and the LEDs just happened to wiggle with the rather weak frame, causing the light to not shine directly on the surface.