SP v. LP setting, quality difference?

[stantheman1976]

Is there really a big difference in the 90 minute setting vs. the 60 minute setting on a DV tape? I'm going to paris week after next and have a bunch of tapes and I just want to make sure I can record ecerything I want. I'm using Maxell tapes if it makes any difference.

[DVWannaB]

If you wish to convert to DVD later, I would recommend the 60 minute (SP) mode. You will notice the difference in conversion. I would dare say you should see the difference without conversion.

[guns1inger]

LP usually involves reducing the the audio from 48 to 32khz as well as reducing picture quality. Personally I wouldn't use it if you want keep the output long term.

[The_Doman]

The DV LP and SP have exactly the SAME picture quality.
They record exact the SAME digital data.
With LP the only difference is the recording tape speed so there is some more change of dropout failure.
Just use good quality tapes and it will work ok.
Ofourse if it's not really needed it's better to use the normal SP mode.

[GeorgeW]

LP usually involves reducing the the audio from 48 to 32khz as well as reducing picture quality. Personally I wouldn't use it if you want keep the output long term.

I"ve recorded in LP mode, and have never had a problem recording 16-bit 48khz audio.

As mentioned by The_Doman, the recording is exactly the same, except for the tape speed -- which increases the effects of a dropout (or error in the tape). Use quality tapes, and you should be ok (ymmv).

Once you have captured to your hard drive, it is the same exact digital video (60 minutes is still about 13gb of dv .avi -- regardless of whether it was recorded as SP or LP), and so the conversion to mpeg will yield the exact same quality (as long as there were no tape-quality issues).

A bigger issue might be in trying to play the LP tape in a camcorder other than the one that made the recording. Not all camcorders use the same tracking for LP, so the LP tape might be playable in camcroder-x, but not in camcorder-y (unless you have tracking controls).

[DVWannaB]

Not to drag this on or anything, but I think that is physically impossible that SP and LP are the same. SP mode generates a better overall picture than LP. That is why they made it the way they did. SP the best picture your cam can give and LP a compromise of quality to get more time per tape. While I agree that LP can be very good, I would not say it is exactly the same as SP. I still maintain that if you want a long term payoff for your work today, and there are no constraints as far as money to buy extra tapes or the fear of missing a shot of an event that is longer tan 60 minutes, then SP is the smart money move.

[guns1inger]

I know with my DV camera the manual even states that there is picture degradation and a general lower quality to LP mode recordings. Yes, you can override the settings in some cameras and get 16bit/48khz audio, however you don't get the same runtime. Otherwise all tapes would run 90 minutes at top quality.

[bugster]

I know with my DV camera the manual even states that there is picture degradation and a general lower quality to LP mode recordings.

As stated, the video data stored on the tape is exactly the same in the two modes. It is possible that less error correction/protection bits are used in LP (similiar to mode1/mode2 CD burning) to help achieve the longer runtime, but the actual video data will stay the same. Any lowering of quality will be caused by data loss during playback. This will be because the data is more tightly packed on the tape and maybe because of less error correction. I use LP frequently, and when transfrred to a PC, the file size of an hour of LP is exactly the same as an hour of SP. This shows that the amount of video data recorded in the two modes is the same.

[ropdoh]

guns1inger, your manual is wrong.

Definitely the same quality between SP and LP
for both video and audio.

The only problems I have had is that you are more likely to have issues (mainly audio in my experience) playing back LP video on a DIFFERENT camcorder.

I always use LP mode.
And haven't had any problems when I play back with the same camcorder that was used for recording.

[DVWannaB]

ok, I stand corrected. I'll revisit my manual. Maybe its the part I glossed over

[BSR]

Just wanted to confirm, what was said above about it being the same data.
Remember a thread like this probably a year ago with some good links to info, but with a quick search this is what I got.

http://www.videouniversity.com/dvformat.htm

QUOTE:
The consumer-oriented DV uses 10 micron tracks in SP recording mode. Newer camcorders offer an LP mode to increase recording times, but the 6.7 micron tracks make tape interchange problematic on DV machines, and prevents LP tapes from being played in DVCAM or DVCPRO VTRs.

i.e. Same data just packed closer together. Just hope your comcorder doesn't break, then you might not be able to play those tapes back, Dohhh. So be sure to record to DVD.