Call On All Hv20 Owners - To Test For Dropouts
 

CALL ON ALL HV20 OWNERS - TO TEST FOR DROPOUTS

there have been quite a few reports that the HV20 randomly drops out every now and then.

I myself have replaced my HV20 twice because of this issue. i tested with several different tape brands in both HD and standard versions... i used head cleaners and one HV20 actually started chewing tapes after 4 hours of use and two head cleanings....

what is a drop out?

it's when the video cuts out for a second or two.
usually this is because the heads on the camera need cleaning and a simple head cleaning tape will fix it.... but this seems to be an issue with the HV20 it's self.


i think this issue mightn't have been noticed on a large scale for a couple of reasons... the dropouts are so sporadic that people who use the camera only a little bit might never come across it... some people mightn't be aware what dropouts are or that it's a problem with the camera... people using the camera for short takes ( 2 min, 3 min, 30 sec) might have just been lucky and not come across it yet.


how do i test?

the easiest way i've found is - put your camera in front of your TV and record a full hour of tape - the constant movement and sound of television make a dropout easy to detect.

then import your footage onto your computer - make sure you've got 'create new clip on start/stop' selected - after you've imported your footage, if there is more that one file, then you've had a dropout.

you can got to the same time in the time code on your tape to check it really was a drop out and not something else...

report back with what brand tape you were using and how many drop outs, if any, occurred in an hour.


i've found -

JVC PRO HD - 7 or more an hour
SONY HD - at least 1 an hour
SONY Exc - at least 1 an hour

Hi Patrick...........
 

I'm not entirely sure there was actually a question remaining at the end of your post...........

However - It would seem that whatever brand of tape you are using when shooting HDV, the incidence of "dropouts" increases exponentialy the longer you shoot. It is an inherant problem with the "GOP" thing to make HDV work with tapes (never a stable medium).

If I get by with only 3 dropouts on a 60 minute tape on my XH - A1, I consider myself lucky - and I use a cleaning tape before replacing any used tape in the machine.

The same rate is happening with my HV20.

The Panasonic tapes you'll see mentioned everywhere on this site seem to have the best user feedback, but at the end of the day, you ARE going to get dropouts using tape, and at HDV levels, they are VERY noticeable.

What more can I say? It's an extremely poor medium to capture such brittle data streams, and as soon as someone comes up with a cost effective way of doing it better, you'd better believe the entire industry will stampede in that direction.

CS

My HV10... I recorded and imported 30 tapes, only noticed 1 dropout in all the footage...
My HDR-FX7, imported 12 tapes and noticed 3-4 dropouts, but that was a tape I dropped in the dirt... so I don't really count that.
My old Canon Elura 2... I never saw a dropout.. ever... in 30-40 tapes+

I mixed tapes on the HV10 and Elura2, even re-using some

The FX7 has gotten Sony Premium and Sony HDV Master Tapes... that's it...

I record my tapes to the end or very close to the end (52-58 minutes)

chris... 3 dropouts an hour is normal?!!?!
i never had a drop out with SD DV stuff. i am new to HDV though...

i have a friend with the sony A1P HDV camera. he's never had a drop out ever.... that's why i though the 3 HV20's i've owned and the other ones i've been told about and maybe all HV20's were faulty.

the people at the camera store i get my stuff from said it shouldn't be happening.. and they know there stuff. they were the ones that told me other people are having the same problems with the HV20.

are you sure your HV20 and A1 aren't faulty?

hmmm
 

The only drop-outs I've noticed are when there's a shock to the camera:

I shot a band (continuous for about an hour, 2 other cams also shooting) and I was crawling around on the floor getting funky angles and jarred the camera pretty good once and it dropped maybe 4 frames.

This past weekend I was shooting a short and got too close to an actor who spun around and walked right into the camera. I was really disappointed about that drop-off, because it was damn funny.

Jason

The day Canon releases an HV20 like camera that records to flash card can't come soon enough.

You will always get dropouts with HDV because tape, no matter how expensive, will always have imperfections that disrupt recording. HDV uses MPEG2 compression with a 15 frame GOP (Group of Pictures) which means that the slightest glitch in the tape coating loses you 15 frames.Whereas in DV you might see a flash frame or a brief flurry of coloured pixels, in HDV you lose at least half a second of recording. This is one of the reasons why keen HDV users like to record direct-to-disk or have a backup recorder or second camera for important events, just in case.

I've noticed with my two Sony HDV cameras that you will see a few dropouts on the first couple of tapes you use, and thereafter you will rarely see them.

Three dropouts in 60 minutes is either very bad luck or evidence of some other problem - possibly the wrong brand of tape or excessive use of head cleaners. I use Sony Premium tapes in my 2 year old Sony FX1 and I have not yet needed to use a head cleaner.

One thing I think your missing in the equation is the length you shoot non-stop. The dropouts become prevelent when shooting 40 to 60 minutes non stop. There are probably very few peope who do this. I do because most of my video is shooting music sets and I never pause or stop the camera.

so far i'm getting drop outs when using panasonic master series tapes ( out of 2 tapes - more then several drop outs per tape ) .. when i use the cheap panasonic's ( $3 ea) out of 3 tapes i've had 2 drop outs

What tapes? I had an awful time with Fuji tapes in my Sony. No dropouts since switching to Sony "HD" tapes.

Patrick (and others)............
 

No, I don't think three drop outs an hour is "normal", it's just what I'm getting (sometimes). Occasionally I'll get a clean run end to end, sometimes one, sometimes more.

I'm still working my way through a batch of Panny DVM63MQ tapes before I upgrade to the newer version, there must be a reason Panny upgraded this tape stock. I'm hoping that will improve the situation.

As for other factors - both my cameras take a bit of a battering, and we share the house with 8 cats - a sort of giant fur ball with a house around it. Either of these could be taking their toll.

Before I went HDV I had only 4 dropouts in 7 years on my XL1s, and that took more of a battering than my current cameras.

As for using a cleaning tape "too much" well, I'm trying it to see if that improves the situation, so far it hasn't (but I'm only about 6 tapes into this trial).

I guess the bottom line for me is that, untill someone comes out with a guaranteed perfect tape from end to end OR a diffent recording mechanism altogether (I am SERIOUSLY thinking of going over to a Firestore unit) then this is what I'm going to have to put up with on HDV.

As I said, tape will never be perfect and long GOP data streams require it to be just that - ergo, it must fail occasionally, it's just a question of how occasionally that is.

One test you might like to perform will give you an idea of what is going on - go back to your shooting the telly test, but shoot it in SD. If the whole thing is perfect do the same test with the same tape and shoot it in HD. If you get dropouts in HD and not SD it's ...............interesting.

CS

I go between 7-10 min at a time, sometimes 20+ min straight... still no dropouts that I've noticed...

Using my HV20 with JVC HD tape, I've noticed the dustier the outdoor environment the more dropouts occur.

Indoors over 4x60min tapes, 2 dropouts. Shooting 2x60min tapes outdoors in a slight breeze in the Arizona desert, 2 or 3 dropouts per tape. During playback one at the 50min spot on the last tape, goes blue screen for 3 secs.

I believe very fine dust getting into a cam, can get onto the tape path and dropouts result.

dropouts in HD versus SD
 

I've read a few posts that talk like the tape will be more sensitve to dropouts in HD versus SD. Why would this be since the data rate is the same. The same number of bits per inch are being recorded in both modes. Does the "GOP" thing only come into play in HD mode and this might be why we're seeing more dropouts with the HV20. Obviously most people are shooting in HV since they bought an HD camera and even if downsizeing to SD the quality is so much better than shooting with an SD camera.

John ...

Yes, the data rate is the same for both DVand HDV, but an HD frame is about 1.5 MegaPixels while an SD frame is about half a MegaPixel - roughly 3 times as much information is being squished on to the same bit of tape for HDV by the use of MPEG2 compression.

I'm not an expert on MPEG2 codecs, but it works something like this :

Instead of recording every pixel in every HD frame, only one complete frame is recorded (called the I-frame) in a group of 15 frames (the GOP), followed only by the pixels that have changed in the following frames . On playback, all of the frames in the GOP are reconstructed from the I-frame and the differences, but if the I-frame is wiped out by a tape dropout then the group of frames cannot be reconstructed, leaving a big hole in your playback.

So you'll notice many more tape dropouts in HDV than you will for DV.

Tony

Okay Guys, I had to chime in here.... I am using $3.00 TDK tapes from Costco, and I am just no seeing any drop out issues. I do sometimes wonder how accurate the camera is with respect to appending new footage after the camera is restarted, because I notice blank spots and time code restarting in some situations, but I just haven't seen any drop outs during a shot, at this point. This includes the 3 hours of shooting I did for 48 Hour Film Project film last month.

Already chimed in here: http://www.hv20.com/showthread.php?t=1288 and here: http://www.hv20.com/showthread.php?t=1181

OK Peter. I hear what your saying, that you think it's 99 percent, or some high percentage, of the dropouts are do to dirty heads. I have to disagree with you. I just don't think all of us, or even 50 percent of us experiencing dropouts, due to dirty heads. How can we test this and come up with a scientific conclusion as to where the dropouts are or aren't coming from? It may be difficult and time consuming but maybe it would be worth the effort.

I think that Tony is probably dead on with his I-Frame summation. If a bit doesn't get written correctly in an I-Frame it screws up a bunch of frames. Before I-Frame (which I'm guessing came along when HDV did) a changed bit in one frame didn't do that much like a bad I-Frame bit would. Doesn't this make sense as to why we're discussing much more dropouts than were happening with our SD cameras? I'll be honest, I've been shooting videos for 3 years (about 300 archived on my sheves right now) and never owned a tape head cleaner until a month ago and I've only taken it out of my bag once. I think even than, it may have been because of you Peter & that's because I respect your opinions here a lot.

To me it only stands to reason that if the head cleaner has even a mild abrasive in it, you wouldn't want to use it very often. Can we find some unbiased documented information about the use of mini dv tape head cleaners somewhere. I'll go do a little Googling around and if I come up with something, I'll post it here.

I use TDK tapes from Costco. I am currently on the third tape and I noticed two drop-outs overall so far.

If I understand you, I think we're saying the same thing. Dropouts are more noticeable on HDV because of the long GOP encoding - that means 15 frames gone per dropout compared to one frame (intraframe compression) for DV. It's essentially a 1/2 second freeze of the image. Talk about in your face. But I-Frames don't cause dropouts - dirty heads do.

Dry-type head cleaning tapes are abrasive so you don't want to use one more than necessary. And only for 10 seconds at a time. But I think the camera will fail for other reasons long before head wear due to occassionally using a cleaning tape.

I may be wrong, but it seems to me Canon has pretty low quality control on things like dirty heads on the HV20 and dusty sensors on their DSLR's. I've used three brand new DSLR's from Canon and all had filthy sensors. Given how many people have reported dropouts/freezes on new HV20's (including me), those heads must be clogged from the factory. I've run my cleaning tape 2 times (~20 secs.) so far and the amount of dropouts dropped pretty significantly.

So... is the camera defective? Personally I don't think so. But I guess we'll see...

Just a quick thought. From my experience, the first and last 30 seconds of a tape are more likely to produce drop-outs. Also, as most of you already know, switching between Sony and most other brands of tape may result in head clogs and drop-outs. Pick a quality tape brand and stick with it.

The HV20 or any camera should be able to run for an hour without issues. We produce weddings and ceremonies are often 45 to 60 minutes long. If you're camera handling is rough or you bump it often, expect problems. This is an inherent problem with small, lightweight cameras like the HV20.

For those of you experiencing multiple drop-outs, why haven't you sent it back to Canon?

Because shooting HD, it's normal to have occasional dropouts. If that wasn't a reality, practically everybody who owns one of these new HD camcorders would be shipping them back. Tapes are not always perfect & as Peter has pointed out, heads get dirty occasionally, & lastly, I can live with a few occasional dropouts.

Something's not adding up here. There are many people who have gone HD on other forums and my local NPVA and I have not heard about HDV drop-out issues. For all event videographers, any drop-out equal to 15 frames could be disastrous. If it were true that drop-outs are systemic with HDV, why would anyone go HD for wedding coverage as an example? One drop out per hour is one too many.

Years ago, I used an Elura for capture and experienced occassional A/V drop-outs. But, when I recaptured, they were often gone indicating it was a problem with the capture device. For those of you with multiple drop-outs per hour, are you capturing with your HV20 and are you sure the drop-outs are on tape?

For years I have followed this forum and read many problems reported by GL2 users. Yet, we produced weddings with GL2s with no problems for 3 years. That makes me think that sometimes reported issues on forums may not be issues at all.

That being said, I'll be monitoring other forums for HD drop out problems. If there truly is a problem with the HV20 or especially the more popular prosumer models, then I'm staying SD.
Bob

Bob. I can tell you in my case and I assume this is relevent to what you're saying about capture. I frequently sit back on my couch and watch the tape I'm capturing to my computer by connecting the HDMI cable to my HiDef screen as Pinnacle does it's thing on the computer. With pretty much frequency I will frequently see maybe one dropout per tape as I'm watching it on the big screen. Now what I should do is note the place or time on the video and go back to it after the capture has completed and just play it to the big screen and see if it drops out at the same place. That would be good too know. I had wondered the same thing that you mentioned but with so many of us reporting drop outs and we surely are not all using the same capture program, it leads me to believe it's not a capture problem. Read some of the comments on a similiar thread over on the HV20.

Yeah! I guess it might be bad if the video dropped out just about when he said "I da da da da do". Maybe you better practice the use of "voice overs" - over dubbing. Think they might notice? No - All kidding aside, if I was shooting weddings, I would be investing in the best quality tape I could purchases, which at the very least, would mean scaling up to HD minidv tapes.

I've only captured about three hours of video so far from my HV20 to my computer and haven't noticed any dropouts (I've shot maybe 15 hours total so far.) Today I was watching footage playback from the camera on my TV and on the second viewing there were two dropouts where on the first go round there were none. Can anyone confirm that the dropouts they're seeing are really recording dropouts, and that we're not just seeing playback problems with the camera?

In a way it doesn't really matter if the dropout is generated while recording or only on playback, since the only good dropout is none. But at least if it was just a playback problem and the data on the tapes was otherwise intact, there'd be less worry around this for mission critical recordings like weddings.

Peter,
Can you play that tape on your HV20's LCD to confirm the drop out occurs at the same location? Better yet, can you play it on another device or try capturing it as SD on a more robust editing deck like a DSR-11? In my mind, if the drop out moves around or is intermittent then it's a playback and not recording issue.
Bob

Playback dropouts
 

Peter

I'm going to make it a point to stop, rewind, and play back the place where I see a dropout the next time I'm watching a tape on the big screen. Like you say, no matter why or when it's happening, it's bad. At least if it was a glitch that didn't repeat itself, we have a chance of capturing a clean clip by recapturing. It's kind of like when I go to troublehoot someones computer, I always ask, "Is the problem repeatable". Most likely if they say no, than I tell them it was most likely a glitch and there isn't a whole lot I can do until it starts happening more often.

Hmmm...logic tells me that's the behavior of dirt on the tape heads. If it was not there once but showed up the second go round then there is something moving over the tape heads causing this interferance. Maybe for some unknown reason these tape heads are more prone to collecting dust. Being that it just reads 1's and 0's coupled with the long GOP architecture any little interferance would cause this dropout.

I do get freeze frame effects
 

So I never have any issue in capturing and making DVDs or QuickTime movies. IT all works great.

There does appear however to be odd behavior when playing back from the camera to (as an example) any of my HDTVs. Its intermittent and does not appear to be specific to any place on a given tape.

I will get a freeze for a few seconds then it will continue playing. The tape never stops but its like the data stream gets interrupted or something. It looks like a freeze frame then it starts to pay again.

The same tape will capture to the HD and make perfect unaffected DVDs or QuickTime movies. It may be HDMI related Im not sure yet.

Anyone else seeing this one?

Greetings:

Has this dropped frames problem been resolved by Canon? I bought an HV20 from B&H back in December and although I've only recorded one full tape, I didn't get any dropped frames when I transferred it to my laptop. I plan to test this somemore on my new HV20.

Not necessarily. You can also lose only 1 frame of information on a dropout with hdv. HDV has better error correction than dv and if the dropout occurs at the end of the gop then you only lose the end portion of it.

i've shot box after box after box of tapes, and noticed maybe 2 or 3 dropout in over a year. i also use my camera as a deck for multi-cam shoot ingest. unfortunately something is probably wrong with your camera. i use generic panasonic tape. $3-4 each. you'll definitely have problems if you switch between certain types of tape. search for "dry wet tape"

Not that Im aware of
 

There is no information on this from the Canon side that I am aware of.

It seems to be some HDMI playback issue in so much as I have never had to deal with this in any other area. It may be an HDMI controller chip issue. I would think if this was a "known issue" on the Canon side a firmware update or something would be a fix but thats just a guess on my part.

Could just be your camera. I had a wonderful experience (note sarcasm) with my XL1s with constant drop-out issues that took Canon over a year to finally agree that the camera was bad. Sadly, it turned me off from them completely, even though I had *loved* my GL-1 and had no problems with it, including rarely a dropout, for years of hard field use. The HV20 was my first toe-dip back into Canon product waters and I haven't had a problem yet - said knocking on every piece of wood around me.

I'm using the same Sony premium mini-DV tapes I've always used. And actually these are about 4 years old, from when I was shooting a lot and bought several cases.

This is not a "Canon" only issue. The half second freeze happens when a certain bit gets written wrong on HD recordings to tape. It happens with some frequency to most everyone shooting minidv in HD mode. I believe that many don't ever see it because they shoot a lot of start stop sequences. I'm sure if you shoot uninterrupted for the full hour on several tapes, you will encounter a dropout. There haven't been any statisticss that show one brand tape is better than another as for as reports about this problem.

If I was a professional shooter shooting HD clips, I would most certainly be purchasing HD certified mindv tapes. Since I'm not, I will live with an occasional drop out and continue to purchase my Sony Premium tapes from B&H for about $2.50 each in quantity.

try limbering the tape
 

Dropouts have been a problem since he invention of helical scanned tape.

Many are caused by dirt, but some are caused by loss of the lubricant applied to the tape in manufacture. Small spots on the tape can become dry, and you get a glitch in the picture.

Old pros used to "limber up" the tape and smoothen out the lube by running each new tape (in player, not camera mode) forward to the tape's end, then back. No more (or fewer) dropouts.

Charles Eidsvik

I'm disappointed by dropouts with my HV20. I generally shoot events, which means a continuous take for up to an hour. I get 3 or 4 major dropouts with each tape. Initially I was using Sony DV premium. I then cleaned the heads and tried Panasonic AY-DVM63AMQ, but it is no better. Fortunately I have been using the HV20 as my B camera. Otherwise it would be a disaster. I am now planning to start capturing direct to laptop via firewire.
Patrick

What do you consider excessive?

The manual states: "To maintain the best picture quality, we recommend using cassettes designed for high definition recording (Canon Digital Videocassette HDVM-E63PR, etc.) and cleaning the video heads frequently with the Canon DVM-CL Digital Video Head Cleaning Cassette or a commercially available dry cleaning cassette."

"frequently", being the operative word.

Tony

I've had mine since Sept 2007, shot more than 20 hours, and have not detected any drop-outs. Some of the shot sequence was 20 minutes long straight. This year I'll be taping long form shoot sequences and will check if any occurs.

Tape dropouts
 

Hi all,

I just got back from a trip to Argentina where I shot my first 7 hrs with the newly aquired A1 (pal), using Panasonic PQ's all the way through. The whole project was shot in SD and I have a minimum of 1 dropout per tape. Over 5 years with my Sony TRV-900 I didn't have any at all, except for when sound peaked. Is it worth having the A1 checked out, or is this a "normal" thing? It seems like a lot of us are struggling with the same problem, it just doesn't seem acceptable from a 3800 euro camera. Not to mention that I can't really afford it timewise to service the cam right now. Any suggestions that haven't already been exhausted?

Bets regards,

Magnus