A few weeks ago, John Nelson of IDV Solutions posted an infographic describing how to simulate tilt-shift photography using aerial imagery from Bing Maps. You can see his guide on visual.ly.
While using Bing Maps imagery as a source for pseudo-tilt-shift imagery is an interesting idea, I think John has missed a trick, because he only uses Bing Maps 2d aerial imagery. Aerial imagery is shot looking straight down from above, so that all the features in the image lie on an essentially flat plane parallel to the lens. Therefore, there’s no reason to expect that features lying further away from the focal point of the image would be any more out of focus than those in the centre (even if this were a scene from a model village, which is what the tilt-shift effect is generally used to simulate).
I think that a much better effect could be produced by using Bing Maps birdseye imagery, which is shot at an oblique angle. Therefore, blurring can be applied to mimic the varying depth of field you’d get throughout the image if this were a close-up shot of a miniature scene. Another point to note is that the plane of focus does not have to be aligned to the plane of the image (i.e. the part of the image that is in sharp focus does not have to be a perfectly horizontal band). It can sometimes be more effective to use an oblique plane of focus -that’s what the “tilt” bit of a tilt-shift lens enables you to achieve.
To demonstrate, here’s some quick pseudo tilt-shift Bing Maps birdseye images I made using the technique described in my blog post from last year. They give the impression that the whole world is one big model village….
I’m now wondering if it would be possible to create a “dynamic” tilt-shift filter in HTML5 or Silverlight to apply this effect in realtime as you panned across Bing Maps in birdseye view. Hmmm…..