In terms of film quality, Instax Wide are slightly sharper than Polaroid SX-70 film.
But in terms of camera, SX-70 is the golden standard for me. Excellent lens, accurate focus, compact, stylish, and plain fun to use. I can tolerate the much higher price and slightly lower quality of SX-70 film.
For Instax Wide, I use some custom built cameras to have better lens and manual control.
If you still can find FP-100C or FP-3000B pack film and can afford them, do try them in a proper camera (e.g. Polaroid 600SE, or Polaroid back for medium/large format cameras). You will appreciate what could be achieved by an instant film, but no longer available.
Polaroid SX-70, a new toy with unpredictable fun
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