Q: converting old VHS to DVD's to iMovie, help !

You need to convert the VOB files in the TS-Folder of the DVD back to DV which iMovie is designed to handle. For that you need mpegStreamclip:

http://www.squared5.com/svideo/mpeg-streamclip-mac.html

which is free, but you must also have the  Apple mpeg2 plugin :

http://store.apple.com/us/product/D2187Z/A/quicktime-mpeg-2-playback-component-f or-mac-os-x

(unless you are running Lion in which case see below))

which is a mere $20.

Another possibility is to use DVDxDV:

http://www.dvdxdv.com/NewFolderLookSite/Products/DVDxDV.overview.htm

which costs $25.

For the benefit of others who may read this thread:

Obviously the foregoing only applies to DVDs you have made yourself, or other home-made DVDs that have been given to you. It will NOT work on copy-protected commercial DVDs, which in any case would be illegal.

And from the TOU of these forums:

Keep within the Law

1. No material may be submitted that is intended to promote or commit an illegal act.
3. Do not submit software or descriptions of processes that break or otherwise ‘work around’ digital rights management software or hardware. This includes conversations about ‘ripping’ DVDs or working around FairPlay software used on the iTunes Store.

If you are running Lion or later:

From the MPEG Streamclip homepage

The installer of the MPEG-2 Playback Component may refuse to install the component in Lion. Apple states the component is unnecessary in Lion onwards, however MPEG Streamclip still needs it. See this:

http://support.apple.com/kb/HT3381

To install the component in Lion, please download MPEG Streamclip 1.9.3b7 beta above; inside the disk image you will find the Utility MPEG2 Component Lion: use it to install the MPEG-2 Playback Component in Lion. The original installer's disk image (QuickTimeMPEG2.dmg) is required.

The current versions of MPEG Streamclip cannot take advantage of the built-in MPEG-2 functionality of Lion. For MPEG-2 files you still need to install the QuickTime MPEG-2 Playback Component, which is not preinstalled in Lion. (The same applies to Mountain Lion and Mavericks even though they have it preinstalled.) You don't have to install QuickTime 7.

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!

VHS tapes home movies to DVDs

Gee whiz !!

I agree with you entirely and use the same method, but the OP states that the video is already on a DVD.

I always (try) show the utmost respect for people with a higher level than myself.

Please try to take the following with good humor.

It's a bit like someone asking for directions to the bank.  And then reminding them that bank robbery is illegal. 

I sometimes notice that people who live in the EU get “excited” when people talk about legally copying a DVD.  I am familiar with the “speech codes” that EU residents live under.  We don't have those in the United States.   There are very few things you cannot say or write in the United States.

Like you, I am opposed to piracy. As a movie fan, I well understand that if the creators are not compensated for their work, there will be fewer movies made.

AFAIK we are in complete agreement!

Except for the following (off topic):

I am familiar with the “speech codes” that EU residents live under.  We don't have those in the United States.   There are very few things you cannot say or write in the United States.

In my view the exact opposite is true. Part of the proof are these very forums.