If you want to take portraits, use [the included closeup adapter]. With the camera focus set to infinity, the point of sharp focus becomes 1 meter.
With the same [closeup] attachment the .9-3m focus setting gives pin sharp results at 45cm. (Selfie range)
The depth of field is quite shallow so it is easy to end up with blurred pictures if you mis judge the distance. I have been known to use a measuring tape and currently have an old accessory rangefinder blu-tacked to the eyepiece.
A bright, clear day is the best time of the day to use your instax 210. This is the only time I’ve gotten results I’m truly happy with. These pictures are exactly what I love and expect from an instant camera. The colors are beautiful! If every picture taken with this camera looked like these I would be the happiest little girl ever.
The problem is that to photograph night scenery we usually use ambient light with the camera set at slow shutter speed. This isn’t feasible on Instax 210 since the 210’s shutter speed can’t go very slow (the minimum is 1/64s)… Note that the Instax 210’s lens is a f14 lens, which means its light-gathering ability is poor (to put things in perspective, iPhone 5s has f2.2 lens, and Nexus 5 has f2.4 lens). Even though it has ISO800 film, the overall combination is still inadequate.