Hello All --

I'm a newcomer to large format photography and to this forum, so please bear with me. I've searched for clarification on the following subject but have not found a completely clear response.

I've recently bought a Shen Hao 4X5 camera and have been practicing by taking polaroid 55s. My question concerns the similarities and differences between instant sheet film (like the 55) and instant pack film, specifically Fuji 100C 4x5. As far as I can tell pack film is just that: it comes in a pack of 10. One of the main reasons for using instant film, however, is to check composition, focus and exposure on a single photograph basis. I'm I to understand that I cannot do this with the Fuji pack film? Do I have to shoot the entire pack? Forgive me if this sounds stupid, but that doesn't seem to make much sense.

Also, I have the polaroid 545 holder. There have been mixed comments about whether or not the Fuji film can be used in this holder. Any thoughts? Should I just buy the Fuji holder so that I could use their quickload film at some point in the future?

I sincerely appreciate all responses.