One last question about capturing from tape

Question

I have a box full of family VHS tapes that I will be capturing into the computer to digitally archive. However, I want to make sure I am doing it the best possible way. These are the two things most important to me:
1. Quality
2. Longevity
1. Quality
I have a VHS/MiniDV JVC SR-VS30 deck connected via firewire into my 2014 iMac. I know that firewire is typically the best option when capturing DV footage into the computer. However, is this still true for VHS and other forms of old tape. I can hook anything up to this deck via composite/s-video in and go out through the firewire connection. However, I wasn't sure if firewire was the best coming from a VHS tape. I also have an old video capture card that has a straight s-video/composite input. Which would be more native to the VHS/analog tapes as far as keeping original quality and the best possible image?
When I use the JVC deck, some programs will capture the vhs tapes and others won't because they won't recognize unless I'm using the DV side. For example, FCPX recognizes the deck, but when I go to import unless it's a dv, it will say "no tape" and I cannot capture anything. iMovie will capture files as .DV. Quicktime will also recognize the deck and capture files as apple prores MOV files. When I compare the QT and iMovie, the QT files look better in my opinion, though I don't know if they truly are. The iMovie dv files have jagged edges like tv lines or something during quick movement and like others say about firewire it looks a little "milky" (though I know this isn't necessarily a bad thing). The QT clips don't necessarily look sharper, but they don't have the hideous jagged edges.
So my question before I start this large project is:
Which capture methods above would you use, or what else would you recommend for best quality?
2. Longevity
Which file format would you recommend saving these files (or just keeping them as they are at capture) for long term storage? When I come back to these files in 10 years and need to convert them to something new, I want them to have the greatest chance of being compatible with whatever lies ahead. There are so many different file formats.
Many thanks for any help along this long process

Answer 1

I want to make sure I am doing it the best possible way.
I have done lots of that.
For maximum quality here is my procedure:  ADVC300 > iMovie 06 > iDVD 09/11. 
To get your VHS video into iMovie, use the Grassvalley ADVC300 .  With the ADVC300 Audio and Video go in, FireWire comes out. It also comes with a nice Macintosh application that works flawlessly with iMovie 06 and iDVD 09/11 (I have used it a few times with iMovie 11).
The ADVC300 has been discontinued by the manufacturer. The included software (which is not really necessary but does enhance performance) is not compatible with OS 10.7 or newer.  You can still find the ADVC300 for sale in a few outlets as well as eBay. It will sell between 50% and 100% ABOVE its retail price. Yes, it's that good.
If you can’t find the ADVC300, use the Grassvalley ADVC110.
I have a drawer full of analog-to-digital converters.   After using the Grass Valley ADVC300 I find nothing else acceptable.
The program that comes with the ADVC300 has some nice filters that can improve video and audio of the source material. The ADVC300 will take Audio and Video from any source (VCR, Tivo, Satellite Receiver) and convert it to FireWire (iMovie will treat it like a camera).
I would use iMovie 06 with iDVD 09/11, why?
iMovie 09, 11, and 13 uses 'single field processing' meaning every other horizontal line of the video is thrown out, which reduces the sharpness of the footage. iMovie 06 uses ALL of the image to form the video.  (Also the latest iMovie CANNOT set Chapeters !)
After lots of experimenting I get the best results using OS 10.6, iMovie 06, and iDVD 09/11.  My movies look just like Hollywood!
My primary computer is a Mac Pro, so I just use one of the four hard drives and boot OS 10.6. You can also partition a single hard drive to achieve the same results.
This may seem like more trouble than you want to go through.  However, I find the superior quality to be well worth it.