So, there are two tasks at hand:
- Capture analog video as close to its original form as possible, this includes the interlaced structure of the video.
- Render the video in a format appropriate to the delivery platform.
- DVD video does not support 50p/60p, so you need to author as interlaced for DVD.
- Youtube does not deinterlace correctly, so you need to author as 50p or 60p. Also, Youtube turns 50p/60p on for resolutions with 720 lines and higher.
So...
First, make sure you have captured interlaced video. You can load it into VirtualDub, turn on double frame rate deinterlacing as I show in my video linked above, and make sure that your captured video is indeed interlaced.
Second, to deliver for youtube you need to deinterlace. To preserve the motion, you need to deinterlace your PAL video to 50p. I started the Honestech software that I have, VHS to DVD 3.0 SE. It has these settings:
As you can see, it does not go higher than 30p. At best you can have either 30i or 30p, but not 50p or 60p. (NTSC is 29.97 frames/s or 59.94 fields/s, also 59.94 frames/s for HD).
Interlacing and deinterlacing options are checkboxes, not radiobuttons. I guess, this means that you can deinterlace your source footage, then re-interlace it if needed.
In any case,
30 fps is the limit, not good enough. But this is my version, yours may look different. If you can choose 50p, please do. Check "Deinterlace source", uncheck "Interlace Encoding".