To dV or not to dV

We're about to get an HD camcorder that we can use for a few years.
The question is: should we stay away from those that record on dv tape and get instead one that records on flash cards/HD, or other ready-to-use media?
I'm afraid that the MiniDV format, with its real-time capture requirement, will soon be as obsolete as the mini-disc audio recorders. Any feedback will be much appreciated.

Alberto

hvx200. best of all worlds.

EX1 best of the new world.

or even better - get a RED and you'll be set for like 10 years.

>or even better - get a RED and you'll be set for like 10 years.

Yup, but the storage! Lol.

I agree with going on solid state recording. Get a camera that shoots on minidv and you're limited to dv quality resolution (or HDV), as well as frame rates and frame sizes. In today's world, you might not want to adopt a quality standard that limits you to a certain level of production (especially when the world is toggling between SD and HD, with HDV yet to be an established standard). Getting a tape deck is additional cost- you might factor a p2 card reader for a mac, but still it doesn't compare.

Where I am, it makes more sense to go for a HVX, partly because most deliveries are still in SD, but with some HD projects here and there. That being said, it shoots on DvcPro50, DV, as well as DvcProHD, which makes it the only camera in it's budget range you can chroma key on.

That being said, there isn't much of a format war going on between the two cameras, so Panasonic (or Sony) is unlikely to to give up either format to adopt the other.

After experiencing P2 world... No way I am going back to DV tapes. Instant replays on the set, near instant digitizing, easy duplication for bullet -proof backup scheme...

I have both Sony EX1 and PD170. I recently did a PD170 shoot where 2 days in a row I got tape dropouts. Maybe a bad batch of tapes or maybe time for a head cleaning. I am SOOO GLAD that tape is going AWAY.

For those who argue that SD delivery is still the norm . . . and it's true, it's GREAT to put HD clips in SD time lines and be able to reposition, blow up, keyframe moves with the extra frame size. Shooting HD for SD adds so much more flexibility and downconverts are fast with the current crop of Macs. With the EX1, importing ranges from 3.5x real time (USB) to over 7x real time (Express slot) so that itself makes up some of the overall time on the down convert to SD.

I guess I was right. My farewell and thanks to the MiniDV format, which opened the door to the editing room for so many with little money.
Many thanks also to all of you for sharing your expertise!

Alberto

It seems everyone loves the solid state workflow. To add to that, tape isn't necessarily a better way to store your rushes, especially mini dvs. Mini Dvs have a fairly short lifespan, so when you factor it in, a reliable RAID is a better solution, with a tape/dvd backup.

Craig, just wondering about HD to SD downconverts. Do you run into interlacing jiggies on resizing HD to SD, especially on the finer lines? And never try running a P170 next to HVX footage- the colors are much nicer on the HVX.

Hmm... The only thing I like about real time capture from tape is that i get a chance to preview the footage as it is going in. With the P2, it's just numbers, and i wish i could get a little preview monitor so I can look at the rushes as it's being ingested (even if it's playing in fast motion).

But my overall take, solid state wins hands down. If you're working in an almost full HD environment, the EX1 offers sharper images with various HD frame sizes, but with mpeg2 compression and 4:2:0 color space. I haven't worked with EX1 footage, so I would be cautious about the mpg2 and 4:2:0 color space. The HVX200 offers the choice of multiformats, and the other features I mentioned. It doesn't shoot full HD 1020 size, but it's almost a definite choice for areas with one foot in SD and another in HD. And yea, the HVX also allows you to shoot on mini DV (in case you run out of p2s and happen to have a mini DV tape).

For more information, read up on Adam Wilt's article. Yup, the opinion here so far generally seems to imply the death of mini dvs. Yea, it had its time back during my school projects too.

> a reliable RAID is a better solution, with a tape/dvd backup.

I really like the idea of DVD (optical disc) backup. I've been using DL-DVD. Later this year Sony's U1 (XDCAM disc) will be firmware updated to be used as data backup . . . any data whether XDCAM HD, EX1, P2. XDCAM data disc backup should be very secure although not cheap.

>Craig, just wondering about HD to SD downconverts. Do you run into interlacing jiggies on resizing HD to SD, especially on the finer lines?

Yes, I'm seeing it with fine lines. There's gotta be a workflow to solve this otherwise we'd be seeing this on commercial SD DVDs. I'm not seeing when I do compression for web though of course.

>I haven't worked with EX1 footage, so I would be cautious about the mpg2 and 4:2:0 color space.

Given the color corrected footage I've seen from both Magic Bullet and Color, the 4:2:0 holds up well. I've only seen a scant few chroma key examples but they hold up well to. I suspect this is because while the ratio is 4:2:0, the number of pixels in 1920x1080 means those samples are quite close together, creating clean edges.

I do think the EX1 has some "key" advantages over the HVX200. Longer record times on the cards, much faster data transfer, higher resolution (and no pixel shifting) and more control of Depth of Field due to 1/2" chips. While there can be some "rolling shutter" issues in some cases (not common), I've yet to see any "real world" disadvantages of 4:2:0 vs 4:2:2 specific to the EX1 (which is much higher resolution than other 4:2:0 cameras). I also like that the EX1 has much less noise / great low light performance compared to HVX also.

Keep in mind the EX1 has 10 bit 4:2:2 Uncompressed out of HD-SDI if one really wants that.

Now add the fact that Sony is announcing a 60GB hard drive recorder that connects to camera SxS slot OR it can be used to dump cards in the field (drive uses the smaller camera battery for up to 10 hours of power) for probably around $1500 (we'll know Sunday) this adds greater record flexibility.

If you'd like an EX1 with interchangeable lens ability . . . EX3 will be announced tomorrow.

I really like the EX1 eco-system over P2 overall. Obviously just my preference but I just wasn't happy with some of the drawbacks (for me) of the HVX200 and Sony answered my concerns with the EX1.

> wish i could get a little preview monitor so I can look at the rushes as it's being ingested (even if it's playing in fast motion).

Maybe not quite what you're looking for but both the Sony Clip Browser and Sony XDCAM Transfer tool allow you to screen the clips and the Transfer Tool can be a decent logging tool too. I believe you can play the clips while they're importing too although usually I'm looking at other clips from the same card while a given clip is importing.

> tape isn't necessarily a better way to store your rushes, especially mini dvs. Mini Dvs have a
> fairly short lifespan, so when you factor it in, a reliable RAID is a better solution, with a
> tape/dvd backup.

Gotta disagree there. While Mini-DV tape isn't a robust tape format, they still tend to be less cranky than pure data. Data on drives can get corrupted, and if the drive itself is damaged or corrupted, you can lose about 100 tapes worth of data in a split-second. Also, since data files are dependent on ever-changing computer software and hardware, they can be messed with even if the original data were intact. Every time you access a file, it's at risk. Every time you copy the files to another storage device, they can morph or change.

That, and the fact that timecoded tape allows you to recapture easily. So you can always make a digital backup copy (captured clips) easily. You can't say the reverse is true -- to backup clip files to tape, it's hours and hours of work, and it still doesn't safeguard your editing decisions.

When a tape is damaged, you tend to lose only a bit at a time (eg. pixellations every 20 seconds). It's possible to cut around it. Even if a deck goes haywire, you can often retrieve other parts of that tape and get something. With digital files, it's often all or nothing -- an incomplete QuickTime movie usually will not play and cannot be converted or edited; even if you have 95 per cent of the file, it is still likely that you won't get the clip to play, and there's no way to tell the file to "ignore" corrupted portions. File corruptions also tend to look much worse than tape corruptions.

Finally, tapes can withstand transportation better than drives, even though drives are much more portable.

Tapeless workflow is probably the wave of the future; it just hasn't been perfected yet as far as I can tell. They have to figure out a way to make it as robust and tangible as professional tape standards.

I have a batch of Mini-DV tapes going back seven to eight years. Most of it is still fine. I usually don't trust drives to last that long...especially drives that are cheap enough to be considered good for storing huge amounts of archival data. As storage space continues to tumble in price, of course, this will change.


www.derekmok.com

> File corruptions also tend to look much worse than tape corruptions.

True. The same can be said about digital errors versus analog errors on the VCD versus VHS mediums years ago. When there is an error on the disc, it blocks and pixelates, on analog mediums, they just get a little fuzzy, eventually resulting in snow (romantic terms, eh?).

I think the answer to archiving has been LTO tapes. I've seen some of them, but never actually seen the limits of the medium or how reliable it is. Theoretically it's more reliable than hard disks. That might be the answer to archiving rushes, with about 800 gigs per tape.

Thanks for reminding on the corruption bit. Yea, the corruption is a lot worse when it happens on hard disk than on tapes. Usually I'd have both a Digital Beta archive, a final cut movie, the project file AND the media manager copied clips on a separate drive.

Tapes versus drives in terms of transportability... I was rather thinking of DVD-roms. I had a batch of mini-dvs sent from hong kong, that couldn't play or digitize properly. It broke up every couple of seconds at some parts of the tape. It was so bad (around 20 mins viewable per hour of shoot, or 1/3 useable) we asked them to check the footage again and resend. We were suspecting the radiation at the customs check might have screwed up the magnet on the tapes and also thankfully they didn't send us the only copy of the tape. I doubt it was recorded on LP mode either.

With digital formats, you HAVE to store copies into at least 2 different mediums (or hard disk). The only issue with hard disk is that if one fails, it is around the time when the batch of hard disks start to fail.

The way i see it, the difference isn't that big when we're talking mini DVs vs hard disk reliability. They both have pros and cons, with mini DVs giving the slight edge currently, but with digital storage fast catching up. Digital Beta is far more robust and reliable as storage than either.

>
> >Craig, just wondering about HD to SD
> downconverts. Do you run into interlacing jiggies
> on resizing HD to SD, especially on the finer
> lines?
>
> Yes, I'm seeing it with fine lines. There's gotta
> be a workflow to solve this otherwise we'd be
> seeing this on commercial SD DVDs. I'm not seeing
> when I do compression for web though of course.
>

The squiggies are likely caused by interlacing lines on SD (same as what you get with fonts, i believe also similar theory to quantization errors when going on to a lower audio sampling rate). When compressing for the web, you deinterlace the footage, so it shouldn't be apparent, and also the fact that it's a lossy codec. To get rid of it, I think Nattress was mentioning including a soft touch with a vertical blur filter or a very gentle gaussian blur setting.

>
> Keep in mind the EX1 has 10 bit 4:2:2 Uncompressed
> out of HD-SDI if one really wants that.
>

That's similar to capturing DV over SDI via Kona 3. You capture uncompressed, and depending on the setting, it adds a chroma smoothing. An alternate workflow, but doesn't really bring the same benefits of shooting in an advanced color space.. at least in theory. The chips might prove the difference.

> Now add the fact that Sony is announcing a 60GB
> hard drive recorder that connects to camera SxS
> slot OR it can be used to dump cards in the field
> (drive uses the smaller camera battery for up to
> 10 hours of power) for probably around $1500
> (we'll know Sunday) this adds greater record
> flexibility.
>

How does that fare in comparison with the firestore? I haven't yet worked on footage from the firestore yet.


>
> I really like the EX1 eco-system over P2 overall.
> Obviously just my preference but I just wasn't
> happy with some of the drawbacks (for me) of the
> HVX200 and Sony answered my concerns with the
> EX1.
>

I'm seeing the HVX as a good answer to the SD/HD transition world, as you can shoot in DV50, DV25 or DvcproHD, so you're not limited to a particular format. As you noticed, down conversion introduces squiggies. I haven't compared the quality of footage from the EX1 vs HVX. But the PD170 vs HVX was a definite show stopper. I know the price range is very different, but at the way it was looking, I'd think it doesn't compare to a Z1 either. But a clean key on 4:2:0 will be quite surprising. I bet they captured via HD-SDI outs, but it's still surprising. Hair and movement would be pretty hard to get out cleanly, also the mpeg2 compression might cause some further complications.


> > wish i could get a little preview monitor so I
> can look at the rushes as it's being ingested
> (even if it's playing in fast motion).
>
> Maybe not quite what you're looking for but both
> the Sony Clip Browser and Sony XDCAM Transfer tool
> allow you to screen the clips and the Transfer
> Tool can be a decent logging tool too.

Is that the same as the P2 log and transfer in FCS2? Personally, I am afraid of renaming the p2 clips because you might get reconnection issues if the .mov goes bad, so i usually keep the Panasonic generated clip names and rename it later. But during the DV log and capture days, I usually watch the clips as it's going in and use that time to plan my edits. With the P2 log and transfer, it seemed a little crashy on my G5 FCS2, so i try not to do anything when it's transfering.

Quote
> Keep in mind the EX1 has 10 bit 4:2:2 Uncompressed
> out of HD-SDI if one really wants that.
>

That's similar to capturing DV over SDI via Kona 3. You capture uncompressed, and depending on the setting, it adds a chroma smoothing. An alternate workflow, but doesn't really bring the same benefits of shooting in an advanced color space.. at least in theory. The chips might prove the difference.

Not quite. If you're coming from the EX1 camera head (rather than SxS) that 4:2:2 10 bit Uncompressed is UNTOUCHED by the codec. It's straight off the head so it's TRUE 4:2:2 10 bit Uncompressed. This is something that the HDV200 does not do (you're getting DVCPro HD compression). Full 4:2:2, full 10 bit, NO compression. Of course one needs some FAST capture ability (RAID) or maybe AJA to ProResHQ. In other words if you can capture from the head, pre codec, you get "the real deal."

Quote
How does that fare in comparison with the firestore? I haven't yet worked on footage from the firestore yet.

Firestore can't capture XDCAM EX codec from the EX. Sony's new drive attaches to EX camera SxS slot and takes the full 1920x1080 35mbps VBR straight in. No hard drive on the market does that AFAIK. Think of it as like a 60GB SxS card which will need to use the small camera battery as power. It can also be used as sort of the Sony equivalent of Panasonic's P2 Store.

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I'm seeing the HVX as a good answer to the SD/HD transition world, as you can shoot in DV50, DV25 or DvcproHD, so you're not limited to a particular format. As you noticed, down conversion introduces squiggies.[/quote

Down conversion only occasionally has the "squiggles" depending on content. As you mention there's ways to beat the "squiggles."

Quote
I haven't compared the quality of footage from the EX1 vs HVX. But the PD170 vs HVX was a definite show stopper. I know the price range is very different, but at the way it was looking, I'd think it doesn't compare to a Z1 either. But a clean key on 4:2:0 will be quite surprising. I bet they captured via HD-SDI outs.

EX1 vs HVX is a show stopper too IMHO. EX1 is sharper, more DOF (when desired) and less noise. Clean key on 4:2:0 isn't surprising when you consider the resolution. "Pixel density" has a significant impact on smooth clean edges for keys especially if one is shooting progressive. I'm not going to say the EX1 is "better" than the HVX for keying but it's holds up very well in the examples I've seen (in progressive).

Here's a bit that explains the math:

The HVX200 has a luma resolution of 960x540. 4:2:2 color sampling gives it a chroma resolution of 480x540.

The EX1 has a luma resolution of 1920x1080 (full raster sensor). 4:2:0 color sampling gives it a chroma resolution of 960x540, i.e. twice the chroma resolution of the HVX200.

Not quite the whole story but it gives you at least some partial insight as to why the EX1 keys reasonably well. Yes it would be better if it were 4:2:2 but keep in mind the pixel resolution really helps it.

and here's Juan Martinez from Sony explaining further:

Quote
Juan Martinez, Senior Manager Technology, Sony, posted the following in another forum regarding the EX1, color space and keying. I thought it was so important given the 4:2:2 vs 4:2:0 arguments I've seen, I'm posting it here. Juan, if you're looking in I'm sure you won't mind it. It's important to get this info out there.

"Actually, the Ex1 outputs honest to goodness 10-bit 4:2:2 at all resolutions via its built-in HDSDI/ SDI interface."

"Now, a word about "color space". In the old SD days, 4:4:4, 4:2:2 and 4:2:0 had absolute meaning and direct correlation to the picture quality (luminance and color resolution). In the case of HD, 4:4:4, 4:2:2 and 4:2:0 are relative. Thus, these ratios have no "real" meaning anymore. Therefore, it would be possible for an HD format with small luminance and color spatial resolution to claim 4:2:2... so, the only way to compare is to count the actual captured pixel resolution. Once, you know the exact number of luminance pixels stored, you can apply the ratio to compare apples to apples (for a given aspect ratio)."

"For compositing, all that is necessary is for color sampling to be tight enough for the keyer to effectively detect the edges. You will find that Ex captures 960 color pixels in the horizontal direction capturing a higher color resolution than some HD formats. The color sampling is also halved in the vertical to 540, which is still suitable for good keying. Lastly, at the core of modern compositing engines are sophisticated keying algorithms that even look at luminance transitions to more accurately detect the edges. Please try keying with Ex 4:2:0. I believe you will be surprised how good keys you will be able to achieve."

"Sorry for the long winded reply. I hope it helps."

"Juan Martinez
Senior Manger Technology
Sony Electronics"

"Now, a word about "color space". In the old SD days, 4:4:4, 4:2:2 and 4:2:0 had absolute meaning and direct correlation to the picture quality (luminance and color resolution). In the case of HD, 4:4:4, 4:2:2 and 4:2:0 are relative. Thus, these ratios have no "real" meaning anymore.

Who's he trying to kid? Color space sure does have a real meaning when doing keying or is he just trying to schmooz you all because it Sony speaking?

"For compositing, all that is necessary is for color sampling to be tight enough for the keyer to effectively detect the edges. You will find that Ex captures 960 color pixels in the horizontal direction capturing a higher color resolution than some HD formats. The color sampling is also halved in the vertical to 540, which is still suitable for good keying. Lastly, at the core of modern compositing engines are sophisticated keying algorithms that even look at luminance transitions to more accurately detect the edges. Please try keying with Ex 4:2:0. I believe you will be surprised how good keys you will be able to achieve."

I'm really choking on this one!

Chroma subsampling notation is indeed relative, and there are "gotchas" like HDV luma resolution being 1440x1080 and DVCproHD being 1280x1080, and HDCAM being 1440x1080, but HDV is 4:2:2, DVCProHD 4:2:2 and HDCAM 3:1:1. It's now a totally abused notation.

It's also not a "colour space". Please don't say 4:2:2 colour space. It's not, never has been, never will be. Please.

Yes, chroma subsampling can indicate key-ability, but it's not an absolute. How do you compare 4:2:2 from 960x540 pixel offset sensors with 4:2:0 from 1920x1080 sensors? Is the 4:2:0 worse because it's 4:2:0, or is 4:2:2 always better??

Graeme

[www.nattress.com] - Plugins for FCP-X

Quote

For compositing, all that is necessary is for color sampling to be tight enough for the keyer to effectively detect the edges.

Duh... which is why DV keys like sh!t.

As far as buying a camera, wait for NAB. Foolish to buy anything before then. I would look into the Red Scarlet coming soon. Portable version of their beauty.

That is all.

When life gives you dilemmas...make dilemmanade.

a lot depends on the sort of thing you shoot.

the guy i work with is out in very rough environments, with no technical backup at all, for extended periods of time.
a file-based system would be useless for him.


nick

As Nick and Derek have said, going tapeless has its downsides and what's best for you depends on your workflow. IMHO, if you can afford to go XDCAM HD that's the best of both worlds (the speed of tapeless w/the proven tape-like workflow).


-A

> Chroma subsampling notation is indeed relative

Ah. The luma resolution. Interesting. I used to look at the 4:2:0 subsampling with the GOP length, as obstacles to creating tough keys.

>If you're coming from the EX1 camera head (rather than SxS) that 4:2:2 10 bit
>Uncompressed is UNTOUCHED by the codec.

Frankly, I don't see a direct HD SDI capture as a practical option on many locational shoots.

However, for the resizing artifacts "squiggies", they are patch jobs. It's like saying that we can underexpose footage as we can always gain it back up in post, or let's just mic it up anyway, since we can always EQ later. You'll be increasing post production schedule. I say, shoot SD for SD deliveries.

As for tapeless vs tapes. There are pros and cons. When you go tapeless, you're always searching for a more secure archiving workflow. And as Nick mentioned, you're unlikely to bring external hard disks, a MBP and P2 cards into a jungle. For tapes, you do encounter problems, but they're generally hardier, and when you run into problems, you don't suffer as severe a heart attack.

For real time capture, vs non-realtime importing of clips, I don't really see that as an added advantage (maybe i'm too used to the log and capture workflow of tapes).

Of course, like i mentioned, the advantage of the HVX200, is that you get the option of delivering multiple formats- being able to shoot on DvcproHD, DV and DV50 (also being able to choose between shooting to tape and going tapeless). In a full HD world, I might look towards the EX1, due to the image clarity, DOF, and being able to shoot at full HD resolution, but I'd also test the mpeg2 compression and see how it keys on moving objects.

And Interlace vs Progressive has an impact too.

Thanks Graeme for your comments.
1920x1080, 4:2:0, Progressive can key "very nicely."
I suspect 1920x1080 4:2:2 "Uncompressed" out of HD-SDI will key even "more nicelyer"

John, the proof is in the pudding. I've seen NICE keys from the EX1 and I've seen it hold up to color correction in both Magic Bullet and Color. Juan Martinez said "try" and people have. That's pulling no one's leg when people have tested and seen the results.

And now the EX3 adds interchangeable lenses. Sony's coming out with 60GB SxS hard drive option which can be used to record from camera or backup SxS cards in the field.

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Frankly, I don't see a direct HD SDI capture as a practical option on many locational shoots.

AJA has a box which is fairly portable. That easily feeds a laptop and one of the small portable RAIDS on the market.

And of course you can do just fine with using 1080p30 off the SxS cards too. The above is for really demanding work and it IS designed to be PORTABLE.

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For tapes, you do encounter problems, but they're generally hardier, and when you run into problems, you don't suffer as severe a heart attack.

Nothing is EVER one size fits all. BTW as someone who has been in the "biz" for nearly 30 years and has been a facility Video Engineer, involved in preservation projects for PBS, MLB, Andy Warhol, video tape is NOT an archive format. Also given the potential issues with tape path tracking and tape stock problems, while tape is usually not all or nothing . . . it is ajada. With tape, checking the last few seconds on a shoot doesn't tell you the story,

With data (whether SxS or P2, etc). if the clip plays, it plays and there's NO DROPOUTS. Yes backup is more critical but redundancy is easy when it's faster than real time. Tape is better/safer in some cases but in many cases data offers a lot more advantages.

In the mid 90s I ran a multimedia dept. for a time. Those CDs still can have the data recalled on on computer with a CD player. That can't be said for the 2", 1", D2, 3/4" tapes. As time marches is on, old decks become scarce and the maintenance due to tracking issues etc becomes critical. I suspect backwards compatiblity with CDs and DVD data discs will be around and plentiful as compared to, let's say a JVC deck playing HDV 720p60 shot from those cameras.

Take your pick put data on optical disc has been more reliable for me. And now that Sony is going to make their U1 an open data recorder (even for P2 data), those XDCAM optical discs look like a reasonable way to go if you don't trust DL-DVD or Blu-ray.

DV keys badly not because of the chroma sampling, but because the chroma is most often not reconstructed "properly" but left looking boxy. That is the "fault" of the codec. However, it will help the DV codec have better generational quality.

Graeme