There are several different lens for the queen of Lomographic cameras, but I have always has some fetish on TunnelVision Lens...
Why? There are four reasons: 1. vignette (dark edges); 2. blur (the center of the image is clear but, around the center, it becomes more and more blurred until the edges are reached); 3. amplifying your vision; 4. macros.
Besides, it is extremely light and you can go with it in your pocket. So easy to install, it comes with several magnetic rings; just glue one of these on the front of your camera (the LC-A looks very sexy with this silver ring) and the lens will be easily attracted.
If you want to preview your shot, just look through the lens before let it be attracted by the magnetic ring; but you can do the opposite…don´t look, just shoot!!! For now, I have just used it with my goddess LC-A+.
Black and white:
On night shots, the dark edges are not easy to see, but you can use the lens just to amplify your vision.
By unscrewing the lens, separating them in two different parts, we can create interesting macro shots (using one of the two parts, “the integrated macro attachment”). “Shoot up to 1 inch (2,5 cm)”.
Tunnelvision Lens is a secret love I have.