Watching the Eurovision Song Contest with friends last Saturday (don’t ask – it’s a family tradition…), we noticed the extensive use of tilt-shift lens effects in the opening “postcard” video preceding each act. Tilt-shift lenses can be adjusted (well, tilted, specifically) to deform the field of focus you’d get from a conventional lens, keeping the subject sharp while hyper-accentuating the blurring in parts of the image that are out of focus.
When applied to a picture shot from above, the effect created by such lenses makes the entire image appear to be a miniature toy model, such as in this image from the introductory video to Estonia’s song entry (it looks even more impressive when seen as part of a moving video):
Dedicated tilt shift lenses, such as the Nikon PC-E NIKKOR 24mm F3.5D ED lens pictured below are expensive and difficult to use, and generally only used in dedicated fields of architecture photography.
However, it’s possible to mimic the effect of a tilt-shift lens digitally using Photoshop.
To try this out, I chose a detail from a snap I’d taken from the recent Norfolk and Norwich Festival, showing the excellent “Always Drinking” marching funk band. I chose to base the image on just the trombonist and the crowd behind him, highlighted here:
I wanted to create the impression that the trombonist and the people behind him were die-cast figures, placed in a “town carnival” scene of a model village. So, here’s what I did:
- First, crop the image and placed it in a new layer.
- Create a new layer mask (Layer > Layer Mask > Reveal All). This layer was going to be used to define an artificial “depth” map to apply when selectively blurring the image. There are several good tutorials on the internet that explain how to create a layer mask for tilt shift effects using the gradient tool (such as this one), so I won’t repeat what they say here. However, while a basic gradient works well when the focal depth of the image varies consistently with the angle of the photograph (which is generally the case in a view taken looking down at a subject from a distance), I found it wasn’t going to work so well with this subject because it was taken at a much more shallow angle. Instead, I started off with a broad reflective gradient that defined an area that was to be mostly in focus across the middle of the image, and then manually edited the mask with a semi-opaque brush to bring out the trombonist. Areas that were masked (i.e. those shown in white in the layer mask thumbnail, and opaque in the main image) were to be in focus, while those unmasked would be blurred. After a few minutes my layer mask looked like this:
- Now, selecting the layer itself rather than the mask, I applied a lens blur filter, using the layer mask as a depth map.
- To make my trombonist look more like a painted toy, I increased the saturation by 20, and lightened the image slightly. I also narrowed the extremes of the input levels in the image and created a slight S-shape curve to emphasise contrast.
- The result is shown below. It’s certainly not perfect, but I’m quite pleased with it as my first attempt at this technique, and I think it creates the general impression I was hoping to achieve – I could probably imagine this as a detail from some amazing model village, with a Hornby model train about to race around the outside… it also only took me a short time to do – with more effort I could have refined the mask further.