The Nokia Lumia 1020 is the world's best cameraphone, which makes it the ideal device for experimenting with camera centric modifications. One such genre of modifications is the idea of attaching an additional lens to the camera, and a sub set of this genre is the reverse lens macro approach (i.e. attaching a ~50mm prime lens the wrong way round) in order to capture super close-up macro shots.
In a blog post Al Reynolds has shared his DIY set up for taking reverse lens macro shots on a Nokia Lumia 1020. It involves building a custom case made up of a Nillkin cover, a 42-52mm ring adaptor (filter reversing ring), and a Minolta MD Rokkor-X 45mm pancake lens. The advantage of the build-on-top-of-a-case approach is that it leaves the Lumia 1020 untouched . Think of this method as creating aa reverse lens macro equivalent of Nokia's camera grip case.
Al Reynolds used Sugru (self setting rubber) to attach the reversing ring to the Nillkin cover, which should stand up well for semi-regular usage, and makes everything look neat and tidy. A finish example, with the prime lens attached, is shown in the photo below.
There are a few issues to be aware of when using this kind of set up. From the blog post:
It was pretty bright sunlight so I had to use the exposure adjustment to avoid blowing out the highlights. The manual focus made things a lot less fiddly than with the 808. For a first session I was pretty happy with the results. I particular liked the second flower shot - you can see how small the flowers were in the photo of the dolly rig.
And here's an example of one of the results, in this case showing a close up of a small flower. Further examples are available on Al Reynolds' blog and Flickr feed.