Around the time last year when I was experimenting with shooting Instax Mini film in my Mamiya C220, I was also building pinhole cameras and lenses. Naturally I decided to build a pinhole lens for the Mamiya and try shooting Instax Mini with it. Thus, the Mamiya Pinstax camera was born.
Getting the exposure right on Instax film is always a challenge. I find that Instax has a very narrow exposure range and it is easy to blow out highlights or underexpose a photo. This made shooting Instax indoors with a pinhole lens even more challenging. Instax film suffers from the worst reciprocity failure I have ever seen and I had to add 4 or 5 stops per exposure. In fact, the first photo took 8 minutes! It’s a little overexposed because I shot these photos using window light and unfortunately the light kept changing as clouds occasionally blocked the sun. The effect was that I had to constantly recalculate my exposure times while taking a photo. Which is exactly what I’m thinking as I posed for the second photo. That exposure took 4 minutes.