Large DVCAM 184 Tape Capacity in Gigabytes?

[roxics]

I can't seem to find this information through a Google search. I'm curious about the capacity of large DV/DVCAM tapes, not in time but in gigabytes.

DVCAM 184/DV 276 tapes. Right now I'm assuming that if a MiniDV tape holds 60 minutes and takes up 13GBs for storage, then a large cassette holding 276 minutes is equal to 60GBs.

Am I correct?

Bonus question. I've never handled these tapes. How large are they physically compared to Hi8 Tapes? Larger/smaller, thinner/thicker?

 

[Alex H.]

The DV codec (miniDV, DV, DVCAM) runs ~5min/1GB.

The full-size DVCAM cassettes are larger than Hi8 in length and width, but are not quite as tall.

 

[Greg_E]

184minute tapes are the same size as all the other full DVCam cassettes, that is:

roughly 5x3x.5 inches the case is 5.5x3.75x.75 inches (Sony spec. tapes)

Now the data issue is not all that it seems, you need to know which tape speed it is running at (assuming you are using this for data backup). At DVCam speeds you get 184 minutes, but at DV/HDV speeds you get 276 minutes. I've never used one of the Sony data backup devices that used these tapes, not widely popular compared to LTO, but I have a pile of tapes here and still have some SD DVCam decks around. Wish the HD DVCam decks didn't cost so much, they would make a great backup record with our students in the studio.

 

[roxics]

Thanks guys.

I would have thought the total data capacity of the tape would be the same no matter if it's DVCAM or DV, but that every minute of DVCAM footage would just take more data than DV. Hence the shorter run time.

 

[roxics]

I guess I never realized how large the large size DV tapes are. I always thought they were the size of an audio cassette or Hi8 tape. But it sounds like they are closer in size to Beta tapes.

 

[Barry_Green]

I would have thought the total data capacity of the tape would be the same no matter if it's DVCAM or DV, but that every minute of DVCAM footage would just take more data than DV. Hence the shorter run time.

Well, yes and no. As said before, the speed of the tape is a driving factor.

DV and DVCAM take up the exact same amount of bitrate. But in DVCAM, they run the tape faster, which lets them spread out that 25 mb/sec across more surface area on the tape, which makes it more reliable.

So the data capacity of the tape depends on how fast you run the tape. Theoretically the tape could hold 276 minutes of 25 mb/sec, when operated in DV mode. But when operated in DVCAM mode, the tape runs faster, so you only get 184 minutes of video storage. In both modes the tape is supporting 25 megabits per second, it's just changing how much physical tape is used to store those 25 megabits.

 

[egproductions]

Well, yes and no. As said before, the speed of the tape is a driving factor.

DV and DVCAM take up the exact same amount of bitrate. But in DVCAM, they run the tape faster, which lets them spread out that 25 mb/sec across more surface area on the tape, which makes it more reliable.

So the data capacity of the tape depends on how fast you run the tape. Theoretically the tape could hold 276 minutes of 25 mb/sec, when operated in DV mode. But when operated in DVCAM mode, the tape runs faster, so you only get 184 minutes of video storage. In both modes the tape is supporting 25 megabits per second, it's just changing how much physical tape is used to store those 25 megabits.

Yup. I believe digital 8 is also the same 25mbps as DV and DVCam but it records using hi8 (8mm) tapes....and running faster, maybe.

 

[roxics]

Well, yes and no. As said before, the speed of the tape is a driving factor.

DV and DVCAM take up the exact same amount of bitrate. But in DVCAM, they run the tape faster, which lets them spread out that 25 mb/sec across more surface area on the tape, which makes it more reliable.

So the data capacity of the tape depends on how fast you run the tape. Theoretically the tape could hold 276 minutes of 25 mb/sec, when operated in DV mode. But when operated in DVCAM mode, the tape runs faster, so you only get 184 minutes of video storage. In both modes the tape is supporting 25 megabits per second, it's just changing how much physical tape is used to store those 25 megabits.

Ahh, that makes a lot of sense. I should know this, I once owned a PD100. lol.
But that definitely clears it up. Thank you

Yup. I believe digital 8 is also the same 25mbps as DV and DVCam but it records using hi8 (8mm) tapes....and running faster, maybe.

You are correct. I was just reading about this and it jives with what Barry was saying. In Hi8 it's a two hour tape but in Digital8 it's a one hour tape because it's running faster but still recording DV25.

 

[combatentropy]

roughly 5x3x.5 inches

I guess I never realized how large the large size DV tapes are. I always thought they were the size of an audio cassette or Hi8 tape. But it sounds like they are closer in size to Beta tapes.

I think you were right the first time. They are the size of a note card.



It was a nice size, large enough to write a good label on, small enough to put in your pocket.