I'm looking into getting into medium format, but I'm fairly new to photography overall. I like the results and the challenges it seems to require. Here are my questions, I appreciate your patience: -I'm confused overall about 120 film. It says you can have 4.5x6, 6x6, ect....but yet it's all 120 film? I dont understand the differences. I was looking on a website called freestyle photographic supplies, and the 120 film they sell doesnt show any mention of size other than 120. -I have an old Kodak that takes 620 film. I dont even know how to describe it, but it's not a TLR. The front folds out to the side...How difficult is it to use it with 120 film? -Those TLR box cameras: --What used models should I look for that are very cheap used but decent enough? --Are you stuck with 1 focal length with those things? Any other basic advice I should know about medium format about I'm very open to, thanks for the help everyone. I was thinking about buying a holga, but if I can get an old, decently working TLR for not too horribly much I want to look into that.