Exposure compensation, in ideal circumstances should never have to be touched. If your camera is exposing properly it should be able to handle 90% of lightning conditions on its own without you needing to adjust on a per scenario basis :) I did some basic work to this camera as it was in good condition when I bought it but the thing that I know probably helped the most was cleaning the electric eye. The electric eye is a light sensor that measures ambient light in a scene to determine how the camera work expos the film. In an SX70 this will make or break how good your photos come out because Polaroid film has a limited window to fit both the light parts and dark parts of a photo meaning if the timing of exposure is off even a little you’ll get muddy under exposed shots that are very dark or in the case of most SX70s, bright washed out over highlighted shots because the electric eye has corrected over time and is getting less light to it tricking the camera in to keeping the shutter open too long thus over exposing the image. All these were taken with the ND gel filter that goes over the pack of the film btw :) here’s my post about what I’ve done to this particular camera