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-   -   Backing up HD need to dub to HD tape? (https://www.dvinfo.net/forum/general-hd-720-1080-acquisition/91796-backing-up-hd-need-dub-hd-tape.html)

Kevin Carter April 18th, 2007 11:07 AM

Backing up HD need to dub to HD tape?
 
I'm making HD tapes, mini DV for small projects such as wedding and other small consumer stuff. not life or death, but here is question:

For convenicne, it's nice to back up mini DV (even HD) to a DVD-R, via camcorder to home unit DVD recorder.
But this DVD-R back up, will not be true HD (high def), or HD at all correct?

And if this is so, is it correct that only way to get a true HD back up is to do the more cumbersome and expensive deck to deck, tape to tape back up in real time?

thanks

Dick Nelson April 18th, 2007 08:52 PM

If I understand you, you want to back up edited projects or clips that started as HDV footage, yes? You can save the raw captured HDV data files to a data DVD-R and preserve it as HD, but you won't be able to stick it into a home player and view it.

Or, you can convert the HDV to an MPEG file and make a regular DVD for viewing, but it then will be standard definition.

Peter Ferling April 18th, 2007 08:57 PM

The other affordable alternative to an expensive deck is a cheap hard drive and a cool, dry place to store it.

Marcus Marchesseault April 19th, 2007 12:00 AM

Why are you backing up the footage? Are you just keeping a copy of the edited footage for future use? Are you trying to keep the footage in a format that can be re-edited? Why don't you want to use DVD-R since the data is just the same as having it on a hard drive? Again, why do you need to backup a tape, what is your purpose? The answers vary depending on your purpose.

Steven Gotz April 19th, 2007 07:02 AM

Just to get the answer in this thread, the only way to back up a HDV tape losslessly is to do the more cumbersome and expensive deck to deck, tape to tape back up in real time.

Once the HDV is captured, putting it back to tape is a little lossy.

Most of us keep the original tape, and also back up the material we used on an external hard drive. No loss there.

One of the problems with the original post was that most of us would disagree with:

"it's nice to back up mini DV (even HD) to a DVD-R, via camcorder to home unit DVD recorder"

That method of backup is virtually useless because the resulting MPEG2 is not viable for further editing. It is only valuable for making copies of the DVD. At that point, you might as well keep copies of the DVD with menus that was sent to the customer in the first place.

Marcus Marchesseault April 19th, 2007 07:35 AM

"Once the HDV is captured, putting it back to tape is a little lossy."

How is that possible unless some sort of transcoding was done?

Steven Gotz April 19th, 2007 07:40 AM

I don't know of any programs that can take a native HDV file, make cuts, and then put it back to tape without reworking the 15 frame GOPs. Some programs are better than others, but all have some loss, as far as I know.

If anyone has proof otherwise, it would be interesting to see. But I know for sure that even programs that claim to edit native are not sending it back to tape untouched.

Ervin Farkas April 19th, 2007 10:19 AM

Steven, what you just said means that once you edit the tape, regardless of the format, there will be some loss. I agree with that, and that's true even in the case of standard definition DV, except maybe if the only editing you've done is straight cuts.

How about a camcorder to camcorder direct transfer (or back to the same camcorder without touching the footage) of HD footage? Let's say your tape is so valuable, you want to make sure you have a second copy and store it in a secure place. In this case there will be no loss, correct? Also, there should be no loss when transferring back to tape HDV footage where you edited in the native m2t format all you've done is straight cuts at the GOP boundary, right?

Thanks,

Steve Leverich April 19th, 2007 11:03 AM

"How about a camcorder to camcorder direct transfer (or back to the same camcorder without touching the footage) of HD footage? Let's say your tape is so valuable, you want to make sure you have a second copy and store it in a secure place."

Ervin, this is what I do with all tapes - I shoot industrial safety/training video, and I do firewire dubs to a second cam so I have two copies of the original material - I then further back these up to multiple hard drives once captured - this because there may be times when old footage is wanted by my clients to use in a newer (but still germaine) application. Tape to tape is the only way I'm aware of to maintain zero loss with high reliability factor.

I think your post (and the one following it) were deleted to keep a mis-communication from turning into a locked thread... Steve

Steven Gotz April 19th, 2007 02:15 PM

Ervin,

Well, with DV straight cuts you don't have any loss. They have not figured out how to do that with HDV as far as I know.

Dubbing valuable tapes makes a lot of sense. And for protection against physical loss, capturing and writing back to tape is not so bad that it is not worthwhile, it is just not as effective as tape-to-tape.

Kevin Carter April 19th, 2007 08:54 PM

Ok guys, thanks for info. To clearify, I just shot some HDV on Sony HD Camcorder which I have two of.

So I now hand over the original mini DV to an editor. If his house burns down, I want a backup that is lossless and a clone of the original.

A dub from camcorder 1 to the same exact camcorder 2 via Firewire should make a perfect clone, correct? (using same HD tape in real time)

I think I got my answer that going FW to a home deck would make a lower quality mpeg -- that's life, but that is cheaper way to go as these tapes run about $10 pop.

Hard drive is great, I use it for my photos, but DV footage, it would be absurd. How much hardrive space is need for an hour of unedted HD footage?

Steven Gotz April 20th, 2007 07:01 AM

Kevin,

Tape to tape, no loss. And yes, the tapes are expensive but they are the most reliable backups.

Unedited HDV is about the same as DV - under 13GB per hour. With the price of 250GB drives as low as they are, you can store around 20 hours of video on a drive costing under $100 - which is about half as much as tapes, and a lot easier to get your video from.

Kevin Carter April 20th, 2007 11:00 AM

Thanks Steve:
I will have some spare 500 GB drives soon:
1) I heard that HDV takes up much more hard drive space than standard Def, no? I thought if would be like double or triple.
2) HD mini DV, not under $10 still anywhere right? if that price point was like $3 of regular that would make decision easier.
3) How cumbersome is it transerfering to hard drive as opposed to dubbing deck to deck? (software wise I only own final cut express DV and Quick Time Pro)

Steven Gotz April 20th, 2007 12:46 PM

1. Well, if you use a digital intermediate like Cineform, then yes, it is three times bigger. However, I archive the native HDV and throw out the intermediate files. I can always convert them again and it is timecode perfect.

2. Still around $10, yes.

3. Since I capture everything to disk before editing, I just archive it and put away the tape. That gives me a tape and a backup.

Kevin Carter April 20th, 2007 08:17 PM

thanks Steve, don't understand a word on point 1.

Kevin Shaw April 20th, 2007 10:33 PM

Quote:

Originally Posted by Dick Nelson (Post 662894)
You can save the raw captured HDV data files to a data DVD-R and preserve it as HD, but you won't be able to stick it into a home player and view it.

Ah, but it turns out you can play raw HDV files on a Playstation 3 if you put them in a folder labeled "videos" on an external hard drive or other suitable device. I haven't tried this on a data DVD yet, but I'd guess there's a good chance it would work.

Boyd Ostroff April 21st, 2007 08:07 AM

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Steven Gotz April 21st, 2007 09:47 AM

Shoot, I never seem to remember what was deleted. Oh well.

Kevin, the AVeL Linkplayer2 that I use can do the same thing from a data DVD. It is how I show my best footage to my friends. I have even been known to take the player with me to hook up to their TV. Better than carrying the camera.

To answer the question posed by Kevin Carter in a more complete manner:

I wrote:

Quote:

1. Well, if you use a digital intermediate like Cineform, then yes, it is three times bigger. However, I archive the native HDV and throw out the intermediate files. I can always convert them again and it is timecode perfect.
What this meant was this: A native 1080i HDV capture is 25Mbps just like DV is 25Mbps. Same file size.

With Native HDV, not all of the frames have all of the information because it is temporally compressed - meaning that the frames contain only the changes from the previous and following frames, and not all of the information they need to stand alone. Frames are grouped 15 at a time in a group of pictures (GOP) --This is WAY oversimplified, I know.

This is hard on a computer, because unlike DV where the program shows you the frame you want to see, with MPEG2, the computer has to figure out 15 different frames to show you that one.

However, if you use Cineform Aspect HD or Connect HD, you take the native file and rewrite it to where all of the frames have all the information they need. This takes a one hour HDV file from under 13GB to around 40GB.

When I capture HDV using Cineform, I can just capture the native file and convert it in what looks like a single step to the user. Or, I can choose to save the native and get the conversion also. But I want to use the converted file to allow my computer to edit without a problem.

Why is this a good choice to save the native as well? Well, if I finish my project and throw away the 40GB per hour files, and save the 13GB per hour files, and I ever need to pull out the project and edit it again, I can always just convert the native files to Cineform again whenever I want. It will look exactly as it did before, and the file name will be the same, and the timecode will be the same, so no sweat. Works great and I save a lot of hard drive space by only saving the smaller files.

Did that help?

Kevin Carter April 21st, 2007 04:49 PM

I understood a little of that Steve. thanks.
so, with FCP express HD, or quicktime pro, I can import the HD video to computer at the 13GB no problemo?

Steven Gotz April 21st, 2007 09:19 PM

Kevin,

You need someone to explain the FCP version of a digital intermediate. And I didn't even know you could capture footage with Quicktime on a Mac.

Sorry, but my Mac knowledge is limited.

Ron Little April 21st, 2007 10:16 PM

Steven, what format do you save your edited HDV movies in to play on a PS3 or Link player? Please give the settings.

Marcus Marchesseault April 22nd, 2007 04:46 AM

2) HD mini DV, not under $10 still anywhere right? if that price point was like $3 of regular that would make decision easier.

You should have no problem using standard DV tape in your HDV camera. They are the same format. If you are just making a backup and still keep the originals, there should be nothing stopping you from using normal (but good quality) DV tape.

Steven Gotz April 22nd, 2007 10:12 AM

The Linkplayer can play WM9 files, which I use for anything over 20 minutes. The quality is outstanding for anything up to an hour or so. I use a 8Mbps data rate - sounds like DV douesn't it - but I cut back to 5Mbps when I expect people to play it from the DVD on their PC. I also cut back my 1080i to 720 since that is all most people can deal with on their television anyway. Why waste bandwidth on extra pixels the HDTV will throw away?

The Linkplayer will also play a M2T file captured directly from the camera. No deinterlacing required. So that is the best option for anything 20 minutes or less. It looks as good as connecting the camera directly to the HDTV.

Ron Little April 22nd, 2007 07:46 PM

Thank you for the info. I will be looking into the link player.

Kevin Carter April 22nd, 2007 08:10 PM

marcus, well back up, but then if you had to rely on it you could not say it's HD.

Chris Hurd April 22nd, 2007 10:04 PM

Actually yes you can say it's HD, because it is HD.

HDV recorded on DV cassette is indeed HD.

That's a crucial thing to understand.

Kevin Carter April 23rd, 2007 10:20 AM

Done follow that at all Chris.
Are you saying I don't have to use the $10 HD tapes, and use instead the $3 standard mini DV tapes, and I'm still getting true HD?

Kevin Shaw April 23rd, 2007 10:29 AM

Quote:

Originally Posted by Kevin Carter (Post 665727)
Are you saying I don't have to use the $10 HD tapes, and use instead the $3 standard mini DV tapes, and I'm still getting true HD?

There's no functional difference between the $10+ HDV tapes and the cheapest miniDV cassettes: the more expensive tapes are just supposed to be less prone to recording dropouts. But the data recorded is identical regardless of the tapes used, just as DV recorded on a $3 tape is the same as DV on a $6 tape. I shot a few hours of HDV on the expensive tapes when I got my first HDV camera and decided that wasn't worth the price: since then I've shot dozens of hours of HDV on Maxell miniDV tapes from Sam's Club with few if any problems. I know others who are using the same tapes successfully as well.

Kevin Shaw April 23rd, 2007 11:17 AM

By the way, since HDV footage captured via firewire to a hard drive is supposed to be a direct copy, that could also serve as a legitimate unaltered backup. I just checked Pricewatch.com and found 250GB hard drives selling for under $54 each, which means you could back up about 18 hours of HDV footage for the same price as using cheap miniDV tapes.

Plus hard drives take up less space than tapes: I just did a comparison and found that two 3.5" IDE hard drives occupy about the same space as 11 miniDV cassettes in their storage cases. So two 250GB drives would hold more than three times as much HDV footage as tapes by volume, or two 500 GB drives would hold six times as much by volume.

Kevin Carter April 23rd, 2007 05:50 PM

Wow , this is news to me.
you are saying that this Sony tape that I bought (15 of) when I got my sony HD camorder

http://www.bhphotovideo.com/bnh/cont...goryNavigation

have no huge advantage over these, which I was just about to sell a bunch of on ebay:

http://www.supermediastore.com/maxel...nidv-tape.html

I totally assumed when I bought my camorder on B&H under their accessory tab, saw tape said: mini DV, Digital HD Video, that for sure one must get this expensive tape to get the HD part or else you are just getting standard def.
Not so? urban myth? I even heard before I got into HD, that the tapes would cost lost more (but also heard that the hard drive space would be triple)

So I should then sell the 15 expensive Sonys tapes on E bay and keep the Maxells?? thanks!
to sum up: there is nothing inhernt in the HD part of mini DV camorder
to lose the HD-ness, if you will, using the older $3 tapes, and no more hard drive storage needed to tranfer to hard drive.

Kevin Shaw April 23rd, 2007 06:59 PM

Quote:

Originally Posted by Kevin Carter (Post 666034)
Wow , this is news to me.
you are saying that this Sony tape that I bought (15 of) when I got my sony HD camorder

http://www.bhphotovideo.com/bnh/cont...goryNavigation

have no huge advantage over these, which I was just about to sell a bunch of on ebay:

http://www.supermediastore.com/maxel...nidv-tape.html.

In terms of your basic ability to record HDV, there is no difference whatsoever. The better tapes should (in theory) be more reliable in terms of fewer dropouts, but most people I know shooting HDV are not using special HDV tapes, just whatever they used for DV.

Chris Hurd April 23rd, 2007 07:13 PM

Tape is the single least expensive link in the entire production chain... so why not simply buy the best you can find? What kind of value are you assigning to your video... is your work worth only a $3 tape or is it worth more than that. Personally I wouldn't use anything less than the $15 tapes (and no I don't get a discount, I pay the same as everybody else).

The more expensive tapes are less prone to dropouts.

Kevin Carter April 23rd, 2007 07:30 PM

Chris, how do you reply to what Kevin is saying? have you done extensive a:b testing? it could be bunch of BS. I thought those expensive tapes were mandatory to achieve HD

Steven Gotz April 23rd, 2007 08:01 PM

Kevin Shaw is correct. The real value of the better tape is reliability. Keep in mind that a bad frame of DV is one bad frame. A bad frame in HDV could be 15 bad frames due to the 15 frame GOP.

I use the good tape. I don't worry that one day I might have voided my warranty or be told that I wore out heads using the wrong tape. I use the good tape because I shoot material that only happens once. I can not have a retake.

Andrew Kimery April 23rd, 2007 08:05 PM

Just to toss in my anecdotal 2 cents here...

Over the past few years I've seen several hundred hours of HDV footage shot on MiniDV tapes and only remember one drop out (which was most likely due to the camera owner/operate not keeping his camera clean, IMO). Many of those tapes were shot in the tropics under less than ideal conditions and shipped back to Los Angeles in zip lock bags (inside a padded box of course) and they didn't have any errors.

IMO the expensive "HDV" tapes are up there w/Monster Cables. On paper there may be a theoretical advantage, but in practice the gains are insignificant or non-existent.

As long as you use quality tape stock and keep your gear clean I wouldn't fret over drop outs.


-A

Ben Winter April 23rd, 2007 08:16 PM

Quote:

Originally Posted by Chris Hurd (Post 666082)
Tape is the single least expensive link in the entire production chain... so why not simply buy the best you can find? What kind of value are you assigning to your video... is your work worth only a $3 tape or is it worth more than that. Personally I wouldn't use anything less than the $15 tapes (and no I don't get a discount, I pay the same as everybody else).

The more expensive tapes are less prone to dropouts.

I agree, it's like people lining up at the gas station with the cheapest gas when it's 10 cents less than the one across the street, and then spend $8 on a cup of coffee.

$15 goes farther in confidence and quality if I want to reuse my nice Sony Master tapes, which of course I do. I'd have less confidence in the nth run-through of a $3 tape.

Kevin Shaw April 24th, 2007 05:42 AM

Quote:

Originally Posted by Chris Hurd (Post 666082)
Tape is the single least expensive link in the entire production chain... so why not simply buy the best you can find?

Because tape is a variable cost which can be controlled, and can make a significant difference in profit margin for those of us with budget-conscious customers. I've compared the $15 tapes to $3 tapes and found no functional difference for my purposes, so that's close to $100 difference per wedding (or other similar event) in my pocket. If I used the $15 tapes I'd have to raise my prices by about $100 per project, which for some customers will be the difference between getting their business and not getting it. I've never had a customer ask what kind of tape I use, but they all care about price.

In theory I agree with Chris' comment, but in practice it doesn't fit what my customers want, which is cost-effectiveness.

Ron Little April 24th, 2007 07:12 AM

Kevin I agree. I did a Greek wedding that took 16 tapes from multiple cams. $48 versus $240 off the quoted price big difference to my pocket. The tapes I buy at Sams come with three labels and I use all three. Once for the original raw footage twice for original raw footage and the third time to master finished movies. I have been doing this for years and haven’t had a problem yet. Doing it this way makes my tapes $1 per use. Not bad. Master tapes get stored away and 99% of the time never used again.

Kevin Carter April 24th, 2007 08:57 PM

thanks Andrew (also others), that's what my hunch would be, and the Monster cable anaogy puts it perfectly.

I assume, you are all, Ron included, talking about your experinces with shooting HD footage, I hope...

Ron Little April 24th, 2007 09:31 PM

Kevin I have two HDV cameras and use the maxell tapes. I figure if I do get a drop out I will use the B roll. If I am shooting with one camera I shoot some of the location for cover shots.


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