hi

I have 8x20 film holder which I loaded both sides today using Foma ISO400 film (actually is 2 sheets of 8x10 per side). The first side is exposed at 1/60 at f22 and developed at HC110 Dilution B for 7 minutes. It turned out well.

The 2nd side of the film is also exposed at 1/60 at f22 (same scene as the 1st one so no change in exposure)and developed in the same manner but it turned out all black (overexposed) with no details at all. The only thing i did differently from the 1st exposure was that I removed the dark slide from the film holder and waited for a few minutes before tripping the shutter. I was walking for someone to walk into the frame I composed.

Would this few minutes of removing the darkslide caused the overexposure? I did covered the dark slide opening with my dark cloth.

I just checked the camera and film holder for light leaks using a torchlight in a darkened room. There is just some light leaks at the lensboard top edge but no signs of light leaks at the dark slide opening or bellows. I would expect such light leaks to cause some streaks or uneven exposure but not overall overexposure.

I would do a test tomorrow by shooting immediately after removing the dark slide. However if you have other suggestions, I would be glad to hear them.