@john_dennis: Your suggestion implies that the MP4 files created on the memory card by the Sony are not split at some designated file size, only to be stitched back together in the software - is that correct that it's one file per record-pause cycle? If so, then yes, copying them directly from the folder would be an easy solution.

If your SD card is formatted exFAT, there is no practical limitation on file size dictated by the file system as there is with FAT32.

My RX10M4 has a ~< 30-minute recording limitation that I understand the camcorders from the same vintage (AX53, AX100) don't have.

Why don't you drag a few of the MP4 clips to your machine and look at the Mediainfo report to see if any two of them are exactly the same size?

https://helpguide.sony.net/cam/1440/v1/en/contents/TP0000557749.html

"When an MP4 movie file exceeds 4 GB, the next movie file is created automatically."

* My VXF1 from pana, do the same even it uses exFat.

I just looked at the card and yes it's exFAT. @FayFen thanks for that link. That information isn't even in the manual that came with the camcorder! So at 50 Mb/s XAVC S, if my math is right, then a 4GB file would be 10.67 minutes long, correct? Soooo the question remains, if the camcorder chops files at 4GB, and Vegas Device Explorer doesn't recognize the device, if my videos are longer than 10.67 minutes (they will be), how do they get joined together for editing in Vegas?

My Sony (but not camcorder) from the same era has no such limitation- copy the clips and you are done. Did you try it? Just record the wall for 30 min.

No I haven't tried it yet, but the information @FayFen posted "When an MP4 movie file exceeds 4 GB, the next movie file is created automatically." According to that page, it includes my model so I don't have any reason to expect a different outcome than what is stated on Sony's site.

Despite what the online link from FayFen said, with a Sony CX405, using the XAVC-S recording format and an SDXC card formatted to exFAT, there is no 4 GB recording limit. The CX405 will produce one MP4 file for the length of the recording. My last recording had a file size of 29.3 GB and a duration of 1 h 21 min. (There might be a 13 hour limit as stated in the online help guide, but using batteries I wouldn't go over two hours at a time anyway, so I've never tested it.)

My work flow is to transfer files using an SD card reader.

@Ecquillii, thanks for the reply, that's great news. I'll give it a go!

@Ecquillii just filmed 15.5 minutes and the MP4 was 6GB, so I confirm what you said, thanks! Wonder why that link has that incorrect information!

Well, the problem is complicated, and the answer even more complicated. And my understanding of all or any of it is partial and unreliable.

First, there are the file formats and specifications of the camera to consider. Second, there is the file system of your media card, and its file size limitations. Third, there is the file system of your computer or media device. Fourth, there is the changing standards over time. Fifth, there is the overlapping of the changing standards. Sixth, there is backwards compatibility of all the moving parts. Seventh, there are different strategies for writing manuals depending on the target audience, and especially if mathematicians with a sense of humour are involved.

I would only be guessing, but the file limitation sizes of 2 GB for AVCHD is part of that format specification, and the 4 GB limitation for MP4 is part of the FAT16 and FAT32 file format specifications. Sony provided 'Sony PlayMemories Home' software to link your camcorder to your computer via USB, and to import and stitch the segments from a continuous recording that was broken up into appropriately sized files back together (up to 13 hours it would appear) without glitches (or so it was claimed), if your hard drive was formatted to the appropriate file system (NTFS or exFAT).

With the introduction of exFAT on media cards, and its increasing adoption by Sony up to the time of the CX405, the MP4 size limitation of 4 GB was negated, but not always implemented in a camera's software. We count on the engineers to communicate all this information intelligibly and responsibly to the manual writers, and for the manual readers to parse it all correctly.

This is the reason Lewis Carroll is so popular.