Untitled photo

This was my first attempt at creating a product shot with light trails. The concept is fairly simple, an LED light with a red gel lights the handlebar as I move it through the frame, and then the flash lights it up and freezes it just before the shutter closes. In practice it's only slightly more complicated.

The first concept to understand is that of the camera shutter, and rear or second curtain sync. Many of you have probably heard of this before, and some of you have probably used it. However when I used to teach action photography I found numerous people that didn't really understand it. When you take a photo the shutter opens to expose the film or sensor, and then after the shutter time is up, it closes. The key thing to know is that there are actually two shutter curtains in most cameras, the first one opens, and then the second one closes behind it. With normal flash settings the camera sends the signal for the flash to fire as soon as the first curtain is full open and the entire sensor is exposed. In rear or second curtain sync the camera waits until the exposure is almost over and the second curtain is about to close before firing the flash. This is key for this shot as it allows the flash image to be after (and on top of) the image created by the continuous LED light.

The biggest challenge in this shot was positioning the handlebar in the frame, both for the light trails and for the final flash image. Originally I used normal sync and positioned the bar using a fixed reference point (a light stand just below the shot). After the flash fired I moved the bar to the left of the frame creating similar red streaks, however the flash image was always a little muddy looking and the red light inevitably left the whole bar with a red cast. So I switched it up and used rear sync, moving the bar through the frame and ending up with it in the right position when the flash went off. It took a lot longer to get it how I wanted, but the end result was way better.

I played around with the brightness of the LED light and the speed of the movement a lot to get the right look, and then I brightened the red streaks up a fair bit in post.

Shot with:

1 x Aputure 120d LED light with red gel

2 x Profoto B1x with strip boxes

Sony A9 and 90mm lens. 2 seconds f/4.5 iso 100