importing mini dv

- does anyone know what could be happening? Is there a way to stop this? Otherwise is there an alternative? Cheap?

Unfortunately, it is difficult to tell "exactly" what is happening without more specific information as the combination of MacOS/QT X, QT X user settings, your specific workflow, etc. all have some degree of influence on "what could be happening."

I suspect that when you say "import" here, you are actually using the QT X "New Movie Recording" option to perform an "on-the-fly" conversion of DV source data being input via the FireWire interface as opposed to the "capture" of the "muxed" DV/LPCM stream and storing it "as is" in a DV file container. (It would have been helpful here if you had included screen capture images of the "Inspector" window both before and after "saving/exporting" your video data to see more precisely "what is going on.") Basically, older MacOS/QT X versions transcoded the input to H.264/AAC using a default setting or a user selectable "High Quality" or "Greater Compatibility" setting. Since Mavericks, I believe this was changed to a user selectable "High" (H.264/AAC) or "Maximum" (Apple ProRes 422/LPCM) setting with the "Greater Compatibility" setting relegated to the Finder "Encode" option. The "Max" (Apple ProRes 422/LPCM) recording option replaces the older AIC/LPCM intermediate editing file workflow and is, I assume, the "Large" file you referred to while the "Small" file version is encoded as H.264/AAC content. Tests on my system indicate ProRes 422/LPCM recordings are on the order of 10 times the size of their H.264/AAC counterparts and approximately 1.5 times the size of the source DV data streams. (Again, it would be nice to see the "Inspector" information to confirm encode formats here and determine specific changes associated with the evolving software.)

If you want "to stop this," then capture the DV content as a DV stream file or as a "demuxed" DV/LPCM MOV file using an app other other than QT X. Since you indicate you don't like the way iMovie automatically breaks your imports into individual clips, you might try an older app like Vidi (FREE!). I know you can turn off the old 2 GB limit option using it. Believe you can then capture the DV stream as one continuous file manually. However, be advised that manipulating one huge file to repeatedly perform NLE (Non-Linear Editing) in iMovie to remove breaks between recorded segments and/or eliminate dropped frames can be a real pain. Usually it is easier and more efficient to load the smaller clips automatically than it is to trim the unwanted content manually in the project.

So if QuickTime 10 sometimes lets me save the DV in raw and other times it does not, is there a reason?

Again, it would really be nice to know which specific version of QT X you are using, what compression format is in the "imported" file before and after saving the data, as well as, the editing specifics of your workflow. Certain actions before saving the file can force an export—usually to "flatten" data to a single audio and a single video track which precludes the saving of compression formats in their original form. This is reflected by the "context adaptive" output options available and, in the case of DV, the dimensions of the encode matrix. I.e., NTSC SD DV videos are encoded at 720x480 for display as "Full Screen" (640x480 4:3 aspect) or "Widescreen" (853x480 16:9 aspect) files. Further, H.264/AAC and Apple ProRes 422/LPCM "New Movie Recordings" of FireWire DV content (at least under Sierra) is also stored for anamorphic display but exported data becomes non-anamorphic. Thus, these various clues you may provide can help assemble a complete picture regarding "what is happening" on your system.

Sounds like you have about 25 minutes and the 5 GB file is probably the raw DV Stream (.dv) and the 480 size is a compressed H.264 QuickTime file.

Not much you can do with the raw DV Stream file except to share or use in iMovie or export it in QuickTime. It's just too big in file size.

DV stream is 640X480 so you can pick the 480 option.

Quality doesn't suffer until you export the .dv file.

If you're going to be editing then you need the .dv file. You say you have dozens so you'll need a lot of drive space. They are about 13 GB's per hour of recording.

I would use iMovie to import the DV files. I have no idea why QuickTime sometimes doesn't allow you the raw source files.

I haven't worked with DV files for a dozen years. I think iMovie makes a break in an import when the original recording was paused. You can join the .dv files after you edit.