DMR-E80H quality questions

[JeffM]

Two questions:

What exactly is dubbing technically? Is it an exact bit-by-bit copy (zero quality loss)?

What is the minimum, but acceptable quality level when transferring VHS tapes to DVD (XP,SP,LP,EP)?
Is XP mode overkill for VCR tapes? The VHS tapes I have are pretty much standard quality, not
high quality S-VHS.

[BobK]

> What is the minimum, but acceptable quality level when transferring VHS tapes to DVD (XP,SP,LP,EP)?

The minimum acceptable quality level for you is whatever you think it is after watching it. Obviously the minmum acceptable quality level for the manufacturer is EP or they wouldn't have made the machine capable of EP.

> Is XP mode overkill for VCR tapes?

Probably. I wouldn't use it.

[JeffM]

What I'm trying to ask I suppose, how does a DVD compare to a standard VHS tape, quality-wise?
How can I rate a VHS tape's quality in terms of DVD quality?

[JeffM]

Found some online specs - Don't know if they are accurate.

Now, how to translate lines of resolution into its equivalent recording mode (XP,SP,LP,EP)?

DVD: 480+ lines of resolution - digital
S-VHS: 400 lines of resolution - analog
VHS: 240 lines of resolution - analog

[piano632]

Roughly speaking:

XP = broadcast quality
SP = S-VHS quality
LP = VHS quality
EP = what streaming video looks like over a 56k modem connection

Recording VHS tapes to XP would probably be overkill, but then again you would be assured there is no quality loss at all. DVD discs are cheaper than videotapes these days, so it never hurts to use a higher quality setting. That way you won't regret it later on. If it were something important/irreplaceable, I would definitely use the higher quality settings. Even though LP is about equal to VHS in terms of resolution, LP will occasionally give you noticeable pixelation during fast-moving scenes or crossfades.

[JeffM]

Ok, if the DMR-E80H recording modes give me these picture resolutions:

XP: 704x480
SP: 704x480 // this correct?
LP: 352x480
EP: 352x240

Recording in EP gives me 240 horizontal lines, the same quality as a VHS tape.
Recording in any other mode would be a waste of lines.

Does this sound logical?

[piano632]

It's not just the resolution lines that count, the amount of bits used per second makes a big difference. EP mode is barely watchable in many cases due to heavy pixelation (as I stated above, it looks like streaming video over a 56k modem connection - far worse than VHS quality). LP might be acceptable for some recordings, but it still will have noticeable pixelation. SP has only slight pixelation here and there. XP rarely has any pixelation.

[JeffM]

Ok, so I have to be aware of the data transmission speed, as if it was a streaming video.
Not just looking at a still picture, but pictures displayed over time?

Found some numbers online, don't know if they are correct:

XP, 1hr: 8Mbps
SP, 2hr: 5Mbps
LP, 4hr: 2.5Mbps
EP, 6hr: 1.5Mbps

56K: 56 Kbps
ISDN: 128 Kbps
DSL: 1.5 Mpbs
Cable Modem: 5 Mbps

EP mode would be as good as streaming video on a DSL line?

[JeffM]

Well, I 'll probably go with SP, to cover all VHS and super VHS tapes.