Hello everyone!
I recently bought my first 35mm slr - nikon fm2n
Had couple of rolls developed at lab, then started developing film myself. The rolls from the lab and first one I developed at home turned out just fine, however couple of next ones show this problem



Is it possible that my camera somehow got light leaks or shutter problem ???
Or could it be poor developing tehnique (I'm using old russian developing tank, because that's the only kind we can get here) ?

Thanks in advance!