Originally Posted by Steve Ruddy
How do you determine when the exposure will be too long for hand holding?
I know from experience what I can usually get away with, but you can always use a light meter (or light meter app on your iPhone or Android) to get a sense of what the exposure requirements will be. Polaroid SX-70 film is nominally about ISO 150, Polaroid 600 instant film has ISO 600 as the name implies (so two stops faster). The Polaroid SLR670a used in this photo uses the ISO 600 film.
The SX-70 lens has f/8 maximum aperture. Because of the large moving mirror in the SX-70 cameras, you'd normally want to keep the shutter speed fairly high, but because an SX-70 photo is pretty much a small finished print, you can get away with relatively long speeds and still have nice (if not critically sharp) photos. I find that I can get away with as long as about a half second exposure if I don't worry too much about scanning to make large prints, and that's just about what my light meter says the exposure was in my hallway for this photo: ISO 600 @ f/8 @ about 0.5 sec or so.
Experience counts for a lot when it comes to making good SX-70 photos. I didn't look beforehand, I just knew from listening to how long the shutter ran that it would be "reasonably" sharp if I held the camera steadily enough. (Of course, given how much white there is in the scene, I also had to remember to set the exposure compensation dial to lighten the image by quite a bit or the meter would have rendered it all dark gray...)
When I want very sharp results indoors, however, I pull out the flash unit or a sturdy tripod.
PS: This one on the tripod, no teleconverter, PO B&W 600 film...