I recently bought a Polaroid SX-70. Now i have a 600 film on it and want to photograph at night in very low light conditions. (portraits)
I do have an external electronic flash (Fuji EF X20) with a wire to the camera via a green flash adapter.
What would be your advice in this situation?
At a distance of 1.2 meter the green adapter takes the aperture to F16. So the shutter speed is used to adapt to the lighting situation.
In low light it can take quite long for the shutter to be open. Will the flash light be added to the ambient light the camera exposes for.
Will it not be highly overexposed ?
The original SX-70 was designed for 160 speed film and needs a conversion to use the much faster 600 speed. Even with a flash, your pictures will be underexposed by several stops. A better choice at this time would be to purchase a pack of 160 film and a flash bar. Even better, one of the solid body 600 cameras with a built in flash.
SX-70 (IIRC) doesn't use X sync. Not sure if this is a problem? With circuits designed for flash bulbs, the flash is triggered before the shutter opens, to allow the flash bulb time to fully ignite.
The original SX-70 was designed for 160 speed film and needs a conversion to use the much faster 600 speed. Even with a flash, your pictures will be underexposed by several stops. A better choice at this time would be to purchase a pack of 160 film and a flash bar. Even better, one of the solid body 600 cameras with a built in flash.
I do not know your adapter nor your flash, but it seems as if the SX70 can perfectly use X-sync with an adapter. I use this one https://www.instantphoto.eu/polaacc/sx70_braun_bvc370_flash.htm but if you look at my site there are other flashes like the Universal or the Polaroid 2350/8400 that do the job as well.
Just dare to waste 2 or 3 photos to adjust your flash. It will be worth it...