How to create in Camera patterns in the background?

We had a great response to the workshop on the 11th at Infinite studio, with loads of positive post workshop feedback. The image technique that stood as the show stoppers were the images created with a simple camera capability know as the "slow shutter" or the "long exposure". Now I know a lot of you are going to ask, isn't the slow-shutter/long exposure destined to produce motion blur or soft silky looks, how did I manage to get the sharp and focused couple in the foreground. Well that's what photography is all about, knowing how light behaves and use it with your instrument to create a piece of art.

We have been working on a series of imagery under the thought of "aesthetic use of slow shutter speed " and we came up number of awe inducing results. I'll make sure I write more about the series in a separate blog post someday however I'm going to break this set down to "How we did it?"

The set up

The whole idea was to create a backdrop out of nothingness with the use of LED lights. Now we had thought about doing it with a ice light or a single LED light but that wouldn't give us the pattern that we see in the results, so we chose Christmas lights or the fairy lights (Mirchi Lights as they colloquially known) . While I would have preferred an open backdrop (however our studio has a white painted wall), we chose a black seamless paper backdrop just to make the pattern standout on its own. The camera (Canon 5D Mark iii) was mounted on a tripod (Manfrotto) with Canon 24-70mm 2.8 L lens. We had Elinchrome master strobe (600 watt) to the left of the camera with a 41 cm beauty dish covered with a diffuser.

The Concept

We wanted only the backdrop to be exhibiting the pattern of the bokeh trail. So I had to choose a rather shallow depth of field such I didn't make sharp lines with the concentric bokeh trails and a slower shutter speed to capture the motion of fairy lights to form those concentric trails. We went with f/7.1, 10 sec, ISO 100 with the strobe sync to fire at the first curtain( Check the basics of shutter speed)

The Result

Since we had the strobe synced at the first curtain, the image of the couple was formed as soon as the strobe fired and froze them in the pose, mean while I had an assistant in the background. swirling the christmas lights in concentric circles. Now there was no light illuminating the black backdrop, thus the chances of the assistant being visible was next impossible unless he was wearing some bright reflective colors.

Here are some of the other images we created using the same technique.

While I did change the modifiers from a beauty dish to a snoot to a horizontally placed stripe softbox, the technique behind the images remained more or less the same with subtle changes in the exposure and the movement of the fairy lights.