miniDV and DVCAM mixing

[Ed Mohar]

Silly little question. Mixing tape brands is bad, but what about tape types with the same brand?

I use the cheap Sony Premium miniDV cassettes for the majority of things on my camera, but I also use a JVC camera that can do miniDV and miniDVCAM and full DVCAM, but primarily uses full DVCAM's.

My issue is that I want to share decks and share miniDV cassettes between the cameras, but could the difference in tape format cause a problem even though they're all Sony tapes?

Anyone have any experience on this? Much appreciated.

[Christopher Drews]

An interesting tidbit is actually a 63 minute sony mini-dv tape recorded at DVCAM is only holds 43 minutes. Weird huh?

As far as codec is concerned, you'd be hard pressed to see a difference between the formats. They both are 4.1.1 with a max bit rate of 25MBs. Although I believe DVCAM can support 4 channels of audio @ 12 bit 44.1khz... Not entirely sure though.

Hope this helps,
-C

[Ben Longden]

The issue is really the use of wet or dry tape lubrication by different tape makers.

If you stick to tapes made by the same maker you will be fine.

My 570 is able to take the MiniDV tapes as well as the DVCAM tape, and I always have a few MiniDV tapes as spares in the bag. Mind you, the only tape stock to go through the camera is Sony.

The reason a 60 minute MiniDV tape lasts 40 mins is simple. When in DVCAM mode, the tape speed is faster... 28mm per sec.

Ben

[Shaun Roemich]

Originally Posted by Christopher Drews

Although I believe DVCAM can support 4 channels of audio @ 12 bit 44.1khz.

Both DV and DVCam (there are full size and mini variants of both - they are the same tape stock, just different quality control typically - I use them interchangeably) are capable of 2 channels at 48KHz/16 bit depth OR 32KHz/12 bit depth. ACCESSING the "extra" two channels in 32KHz mode CAN be problematic though so 2 channel at 48KHz/16bit is MUCH preferred.

[Ben Longden]

Not only that, but 48Khz is the broadcast standard...

Ben

[Christopher Drews]

I've never heard of 4 channels x 32khz@12bit on Mini-DV just DV-Cam. Good to know though. You'd need a DSR-1800 to even attempt something like that... or some variation of that deck.
-C

[Shaun Roemich]

Originally Posted by Christopher Drews

I've never heard of 4 channels x 32khz@12bit on Mini-DV just DV-Cam.

Typically DV equipment would give you the option of recording 2 tracks of 32KHz audio in camera (beginning with the Sony VX-1000) and certain decks (like my old Sony DHR-1000 - the DV version of Sony's DSR-30 deck but earlier) would allow you to add the OTHER two tracks in a linear editing pass. Back in the EARLY days I used to shoot this way and add voice over tracks or music beds in my linear digital suite, complete with Videonics edit controller and LANC deck control (circa '98)

[Tom Hardwick]

I think confusion arises because MiniDV is simply a description of the actual tape cassette, Mini being the adjective used to describe the DV (digital video) tape.

MiniDV tapes can record any flavour of LP, SP, DVCAM and so on, the tape simply runs at different speeds between feed and take-up spool. So Christopher - if you buy a MiniDV tape marked DVCAM it says 40 mins on it, but of course it will run for over 1½ hours in the LP mode.

tom.

[Ed Mohar]

Cool stuff. Thanks.

To recap, so in my A1 I can use miniDV and miniDVCAM (all sony) without issues, to record in HDV or DV

a 63min DVCAM tape running in miniDV will last longer than 63min, since DVCAM tapes are rated at a faster speed

and b/c DVCAM is a higher quality, the miniDVCAM can be more robust than miniDV

[Tom Hardwick]

Originally Posted by Ed Mohar

so in my A1 I can use miniDV and miniDVCAM (all sony) without issues, to record in HDV or DV. A 63min DVCAM tape running in miniDV will last longer than 63min, since DVCAM tapes are rated at a faster speed and b/c DVCAM is a higher quality, the miniDVCAM can be more robust than miniDV

OK, some of what you say is correct. Your first sentence is correct. Tape is just tape, and it's only the label on the outside that gives it a pretty name.

A 63 minute tape runs 63 mins, but in the Mini DV format it will only run 40 mins in the DVCAM mode. DVCAM mode makes the tape run faster, whether it be Premium, Excellence, DVCAM, JVC, Maxell tape, whatever.

DVCAM isn't higher quality. The digital bit-stream is the same for SP, LP and DVCAM.

DVCAM can indeed be more robust as the same digital info is spread out over more tape emulsion.

tom.

[Shaun Roemich]

Originally Posted by Tom Hardwick

DVCAM can indeed be more robust as the same digital info is spread out over more tape emulsion.

And often, but not always, "pro" tape may be of a different formulation with a thicker backing and potentially have a higher magnetic retention value. Sony used to have a poster that hung in many Sony Pro shops indicating what differences were evident in each of their tape stocks. But all these improvements only act to preserve the information on the tape through many variables and don't actually change the digital data (which is NEARLY identical between DV and DVCam, DVCam having locked audio as standard) being written magnetically to an oxide coating on a flexible medium.

[Shaun Roemich]

Originally Posted by Ed Mohar

a 63min DVCAM tape running in miniDV will last longer than 63min, since DVCAM tapes are rated at a faster speed

There are no 63 minute miniDVCam tapes. The longest one can find in DVCam tape speed in a mini case is 40 minutes (+ 2-3 minutes intended as leader/colour bars). A 63 minute DVCam tape would be a large cassette.

[Ben Longden]

Hi Shaun,
I think he means using a large DVCAM cassette in a camera that is able to have the recording mode switched from DVCAM to DV, thus slowing the tape speed..

Ben

[Tom Hardwick]

A point worth mentioning is that the writing speed (the speed of the spinning head against the slowly moving tape) is the same for LP, SP and DVCAM, which explains why there's no difference in the A or V quality.