“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”
Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2
The lid would have to be very off-kilter to create a light leak of that severity. It may be the film holder darkslide or the mating surface of the camera against the film holder. I suggest a simple test: load the holders with black-and-white paper and take them outside in the sun for 10 minutes on each side. Develop the paper and see if there is a light leak. If not, load them again, set up your camera, and place them in the camera as though you are going to make a photograph. Only pull the darkslide, don't expose the paper with the shutter. After letting the paper sit for a few minutes, replace the darkslide and develop the paper. See if there are any leaks. That will tell you where the problem is. If you use a post-it note on each side of the film holders to number them and process the paper one at a time you can find out which ones leak and which don't.
so a friend of mine just sent me a few shots he took with the same camera and sent it to a pro lab for developing. this is what he got.
i guess this settles the case. i'll work on examining my bellows and testing my holders. it's great to know it's not the development nor the tank. i've been running 120 like a madman and it's all been peachy, the 4x5 was driving me nuts.