I've now run 2 rolls of film through my 20's vintage Kodak Folding Autographic Brownie #2, both films are Adox CHS 50. On every frame in the rolls there is a section of about 1/4 of the frame that is significantly less dense than the other 3/4 of the frame. I've ruled out manufacturing defects in the film, since it's in the same place on every frame. Holding the camera in it's normal vertical format the light section is near where the top of the frame would be in the camera. I don't think it's a developer problem either, since the problem is across the width of the frame rather than the length. Looking at the camera the only possible explanation I could think of is that the very first bellows pleat behind the lens likes to flatten out or sag slightly instead of hold its peak, but I can't see that causing the problem. I saw that the problem is that 1/4 of the frame is less dense than the rest, but it could easily be that 3/4 of the frame is extra dense! If pictures would help I can see if I can borrow my roommate's digicam to take pics of the negatives and camera. Any ideas what could be causing this?