Sprocket Holes and Swirling Occuring on Negatives

<p>I'm a beginner at B&W film and processing. I recently had to complete a project and one of the requirements was to shoot and develop four rolls of film. One of my rolls had a bit of light leakage, which I noticed, but there was prints of sprocket holes on the negative where my photo was supposed to appear. The negative looks like it swirled along the strip. Does anyone know why this occurs and how do I prevent it from happening again?</p><div></div>

<p>Fogging from a light leak at some point in the process before the film was developed, probably while loading it.</p>

<p>Did you forget to install the opaque center tube in a plastic developing tank that requires one to be light-tight? That's what that light-struck pattern looks like.</p>

<p>One time I put the center tube in upside down in my Patterson tank, and got that exact same effect on about 2 of the negatives closest to the inside/bottom. I put two reels on the center post from outside the tank, dropped the assembly into the tank upside down. I noticed, while developing, the twirl felt very funny and stiff, and the twirler fit funny as well. Lesson learned, I always leave the center post in the tank now, and push the reels down onto it, before attaching the funnel.</p>