Mini DV stalling at the start

[Ana Conlon]

Hi all

I have a Canon XH A1 and I'm capturing a wedding but I'm having issues with my mini DV tape. This tape starts with the vows (very important) and in the first 5 minutes of the tape its skipping in parts. This means that when capturing the footage its broken up segments with words and film missing.

I'm almost certain that this footage recorded ok (ie I didn't notice the skipping or stalling in the view finder when filming). I've played back this piece of footage a 100 times while repeatedly trying to capture it and I've noticed that the damage is only in certain parts. Also sometimes its doesn't skip in the same places 2 but there are certain parts that it always skips. I've been trying to capture these 5 minutes and glue the footage together in Final Cut but its driving me mad! I probably would be able to piece it all together, except the tape does stall in 4 key places consistently.

I have a feeling that the footage isn't impossible to salvage but I'm afraid to tamper with the tape, for fear I'll cause more damage than good. Any ideas or suggestions would be greatly welcome.

[R Geoff Baker]

DV playback has error correction abilities, but this function is device dependent -- 'better' devices will have better capabilities. To that end, a stand-alone DV deck always has better functions than a camcorder -- so take your problematic tape to a professional dub house with a high-quality deck and ask for a copy of the tape. Typically it will copy without issue, though I have on occasion found that if they copy the problem part a couple of times, and each time the problem exhibits in a different area, I'm able to 'fix it in post' ...

Also possible that your camcorder heads are a bit dirty, that contributes, so a pass with a headcleaner is worth while -- but a pro deck may just be the ticket.

Cheers,
GB

[Ana Conlon]

HI GB,

Thanks for that its a small but important section of tape so I'll try the head cleaning first and if that fails I'll try the latter.

Can I ask what might be causing the problem...would if be the heads during recording or what if its because the camera gets a knock during recording?

thanks

ana

[Don Bloom]

Tapes drop off material during recording and playback and the heads and transport mechanism collect this junk. It's possible that the heads have or had some of it while recording. It is also possible that running a cleaning tape thru to get the stuff off the heads will take care of it. It is also possible that it won't. CAUTION!!!!! Follow the instructions for the cleaning tape exactly. Don't overuse it. If the tape says not to run more than 10 seconds, then don't. Cleaning tapes are abrasive and can do damage if overused.

If that doesn't do it then I agree. Find a good dub house and see if they can "fix" it for you.
You will almost never see a dropout in the VF or LCD. I had a problem eariler this year with pixelation from 1 of my cams and it had to go in for service and I had no idea it happened until I went to load it in. Luckily I had other cams to cut to and could fix some of the pixelation when I had to.
Good luck

[Allan Black]

R Geoff,
my 50years tape experience tells me, if each time the problem (drop out) exhibits in a different area, then basically that's dirt or grit being moved along the DV tape surface as it's shuttled over the tape guides and head.

With much repeated shuttling (or winding) the tape back and forwards over the same spot, it is possible to literally grind the grit into the tape surface so the drop out will appear at the same spot each time.

The answer is to run your tape cleaner before EVERY single important recording, even if it's the next day.
Don't rewind the cleaner when it gets to the end, discard it and buy a new one, if fact buy 2 so you never get caught without one.

Ana, I'd take the tape, your video recorder and tape cleaner to a pro house for help too.

Cheers.

[R Geoff Baker]

Allan, I agree with you in principle but my experience (which is back thirty-five years to the days of 2" tape -- how you manage 50 years of experience in video beats me ... though from one old codger to another it does feel like fifty years!) suggests the possibility that the error correction circuits are able to cope with a frame or two then get overwhelmed, but the precise moment of failure changes from attempt to attempt. That's where the deck will do better -- the error correction buffer will be more robust, and may bridge a minor problem.

My direct experience with DV failure goes back to the time of the dreaded tape mixing fiasco -- 'dry' lube vs 'wet' lube as it was termed -- I had a camcorder that had lived happily on a diet of Sony tape, and after a brief spell of Panasonic tape it all went to pieces. A professional cleaning set it to right, but it is worth noting that some of the debris had attached to the tape -- the problem spread to the playback deck too. Luckily, the dub house was experienced and capable, and all was set to right very quickly.

Note too that the first evidence of this sort of dirty head / drop-out is often in the audio, which is uncompressed and so not part of the error correction or error concealment process. That is not to dispute Allan's advice to follow a strict and complete cleaning regiment -- I agree whole-heartedly.

I should add that the other good habit is to use the first sixty seconds of your tape for nothing but bars -- this is the most likely part of the tape to fail. And I make a habit of 'repacking' -- run the tape forward to the end, then rewind before using. Tapes that have been subject to temperature changes in storage will benefit from this limbering. Don't get me started on 'striping' -- a waste of time and possible problem causer -- real striping was only ever for edit masters, never for camcorders, as camcorders always lay down a new timecode stripe when they record.

HTH
GB

[Allan Black]

Hi RGB ... all good stuff. I had 50yrs with magnetic tape, only the last 30 including video :) The first mag tape I ever saw was paper tape, a thin roll of cardboard sprayed with a magnetic coating, it topped out at around 2KC and wore down very quickly.

But I started professionally and conluded my career with German BASF tape 1/4" through to 2" tape.
Along the way my company used the best 'sounding' tape which was Scotch 960.

There's a company in Sydney called Greencorp Magnetic tape which started up during my time and we participated in their development and production of their mag audio recording tape. So I got to study all the properties and operational use of magnetic tape close up.

Not cleaning tape heads is a major no no, mag dust and airborne grit kills tape and because DV tape travels so slow and machines are used outdoors in all conditions airborne grit is a major killer, especially in windy conditions.

Other tips I've posted here before are, before you eject a DV tape, wipe down the top of the recorder to clean it before you open the tape transport. If you're going outdoors to record and the tape only has a few minutes left on it, change it before you go out, in a dust free area.

Never leave DV tapes lying around out of their cases, store them vertically in the cases in a resealable airtight plastic fridge container with some fresh silicagel in a stable temperature cupboard.

Cheers.

[Ana Conlon]

I'm actually really concerned now....I though it was a one off. I have quite a few weddings to capture and I'm really worry that this may appear across them all. I was sure I'd see any problems during recording in the view finder. So if there are problems with the other tapes, I won't know until I capture them. This wedding is the first for last month so its quite possible the others get gradually worse! Eeek!

I bought a head cleaner this morning and ran it 3 times for 10 second each. This had no effect on the damaged tape. Its behaving the same and I can't see any improvement. This particular tape has been used before. I reuse my mini DV tapes as I was told in college you can use them up to 10 times without any issue. The most I would reuse them would be up to 5 times. Is there any possible way that this might just be the tape because it has been used before? I'm hoping against this is the problem I need this to be an isolated issue!

There seems to be conflicting advice when it comes to the head cleaning tape. Don seems to think using the head cleaner often can damage the heads (I heard this also). But Allan and GB suggest cleaning each time before recording.

I also run a new tape to the end as per Dons advice. This didn't improve the situation either.

GB I'll run the bars and perform the repacking before each recording, that's simple enough. I haven't noticed the first evidence of the dropping out to be in the audio.

Also, it does seem to be a little worse after trying to capture it several times. I think this might be Allan's suggestion of grinding the grit into the tape. I may have even spread the dirt around a little. I also have to say that don't practice any of the tips Allan's provided for care. But I will be much more vigilant in the future. Fear will do that to you!

I will go to a dub house and see if they can get better results but I was wondering if the stand-alone DV deck is very expensive. It might actually be more cost effective to purchase one then go to a dub house several times if I have lots of damaged tapes.

[Allan Black]

Ana, first off please don't 'fear' using magnetic DV tapes. If you follow the advice given here then you'll enjoy happy times not only recording but in post production and your clients will too :)

You won't 'see' tape dropouts in the viewfinder while you're actually recording, only when you play the tape back.

If you live in a city, new buildings, road construcion and repairs etc. send almost invisible diamond hard grit into the atmosphere, the wind blows it around and some of it eventually lands on your video recorder, if you don't wipe it off, when you pop open the transport it can get in there and cause trouble. You can see the this grit and dust when you wipe a cloth over your furniture, it can leave scratches too. Even in the country this occurs.

Unfortunately, as you say, if you just bought a head cleaner then your recorder hasn't been cleaned regularly? So I think your video on your damaged tape is not repairable, as I mentioned the micro grit has been ground into the tape surface at that spot causing the dropout.

I believe the notices about DV cleaning tape damaging DV heads are so folk don't run the tape, get called away and the tape runs to the end, it happens. Heads have typically a 1000hrs+ head life, so running a cleaning tape for 10secs a day won't do any damage. I don't think you need to buy a stand alone tape deck either.

I'd buy some new DV tapes and only use those, following the cleaning advice here.

btw the cleaner tape should be the same brand as the DV tapes you use. HTH.

Cheers.

[Don Bloom]

Well the first thing you should stop doing is reusing tapes. Tapes are so cheap now that it really makes little sense to reuse them. I've been running mini DV tapes since 1995 (VX1000) and have never ever reused a tape even when they were $10.00 each for a 60 minute tape. Why? Simply because things like this can happen.
As for not overusing the cleaning tape, think about it. They are abrasive, sort of like sandpaper and while the old Beta cams had very robust heads the mini DV heads are not as robust (not my opinion but that of 2 very high quality Sony authorized repair centers in my area). That is not to say they will fall apart if you use a cleaner a lot but the tolerances are very close and precise and overuse could be problematic. Plus unless you run in a dusty dirty environment all the time there is no valid reason for running a cleaner before every job. I have used the cleaner when I felt it was necessary and by that I mean after I have run perhaps 50 or 60 tapes thru the camera(s) or I have been using my cams in a hostile enviornment, like a baseball game when dust is kicked up and floting all over the place.
I did have a problem earlier this year as I mentioned above but that was because I had almost 1600 hours of record time on the heads of that particular camera. I had the recording head replaced for a very decent price and am now as good as new. AAMOF I had my B camera gone thru with a fine tooth comb and while it has about 1200 hours of record time the heads are just fine according to my tech whom I trust completely.
As for blacking tapes, I haven't done that since I don't remember when, no need to.
I don't recall saying to run a tape to the end, I hope you weren't talking about a cleaning tape, I'm sure you weren't. It doesn't matter if the tape (not cleaner) is run to the end or not.
Here's what I would do. First stop trying to playback the bad tape (and that may very well be exactly what it is-it has happened no matter what the tape brand) try a fresh NEW tape and record something, preferrably something with a little movement to it. A static shot can be maddening to look at and try to see if somethings there. You start to see things that aren't. Load it in and see what shows. If nothing great, if something, then take the camera in for a good cleaning and alignment of the heads. Make sure the pinch rollers are also checked for proper tension.
Problems like this are a logic problem. First do this, then do that, then do the next thing. One thing at a time until you solve it. Otherwise you don't know what fixed it and if it happens again, then you're back where you are now.
Last, I agree...don't be afraid of tape. It's been around a long time and while it sometimes has a problem so does solid state. Use fresh new tapes for every job. Why bet a used tape on a $1000 job when for $2.00 you can buy a new tape.
Good luck

[R Geoff Baker]

I doubt you want to invest in a good stand alone deck -- the better ones will run to 5K or more.

Quarantine the problem tape, don't run it again in your camcorder. Let the dub house sort it out.

Stop recycling tapes. They are cheap -- just use new ones.

Develop good tape handling habits and stick with them -- repack your tapes, start with bars, don't reuse or reshoot, don't eject mid shoot, don't shuttle the tape mid shoot in less you really really need to ... Store your tapes properly.

I've largely moved now to solid state recording, but I still have a couple of hundred tapes in the archive that get used occasionally -- truth is solid state has it's own set of problems and worries!

Cheers,
GB

[Jeff Pulera]

I posted a response the other day, or so I thought, but it's not here. I either never hit the post button...or it got deleted by management.

My response was that when the glitching is random - it is not a bad frame that repeats - you MAY get better playback results using the analog outputs of the camera rather than Firewire. Something about the D-A error correction circuits I guess. I've used this trick many times over the years to save my butt.

I have a capture card with analog inputs, so that's how I capture in that case. If you don't have that option, maybe you have TWO DV cameras with analog inputs, such as Sony VX-2000. In that case, you can dub from one DV tape to another using the analog connections and possibly remove a lot of the problem.

No guarantees but has helped me in the past. I put a link to a blog post I did about this issue with before/after images in my previous post. If that got it deleted, how about just deleting the link then if I am violating some policy, so people can benefit from the main posting at least. I'm not selling anything ;-)

Saving Compromised MiniDV Footage - Safe Harbor's Tutorials blog - Safe Harbor 800-544-6599

Thanks

Jeff Pulera

PS - I've been re-using miniDV tapes forever, has not posed an issue. Shoot events mostly, so one long record pass, one long capture pass. Not worn out at that point...in fact, just as likely to get dropouts on NEW tapes!

[Ana Conlon]

Hi all again,

All great advice and I now have a new strict policy of not reusing tape. It wasn't the cost, I was going on advice I was given in college. Either way its not worth the worry so even if you can reuse tape I'm not taking any chances!

I like Dons tip of getting the camera cleaned ....it's due an MOT I have it a year now so a good once over can only help. Don I don't know where I read about running the new tape through...maybe I'm mixing it up with advice from another site?

I'll know during the week if this is an isolated problem, I've a few more weddings to capture. I'm pretty stressed worrying about it. I can deal with this one wedding but if there is more I'll tear my hair out! I performed a few test last night and the camera is grand. I'm covering a wedding today and tomorrow and I have just come down with a really bad flu. Between worrying about my tapes and feeling sick this won't go down as one of my best days!

I'm going to investigate solid state. I'll have to educate myself on the pitfalls before the move. And thanks for the link Jeff I'll have a good read of the advice. I'll report back and let you all know how I got on with it all.

[John Peterson]

Had a similar problem with my Sony VX2000 two years ago.

Both Sony and Panasonic and the Service Center I brought it to said that the transport in the camera wasn't designed for 83 minute tapes. Only 63 minute tapes.
I used 83 minute tapes for a number of years, but now that the transport is a little worn the problem became exacerbated.

All three said that the problem shows up at the beginning of the tapes since that is the point at which the transport has to drag the largest volume of tape across the heads.

Could that be your problem?

John

[Ana Conlon]

I just though I should come back to this thead I started. I never really posted a update on my progress. The problem was miss alined heads, I found this out after I had my XH A1 serviced. The skipping appeared on the odd tape just in a small sections but I was able to work over the problem by hiring a professional stand alone deck. Just reading back over the thread makes me a little sick...I was so stressed over this but thanks to all the good advice I got though it unscaved.

Thanks to all of you for the great advice...I hope I never experience anything like it again!