1hr take: class 4 cards OK, h4 audio sync drifts

J Davis

J Davis

Veteran
I have been running tests just because I like to know my gear before I start shooting.

SDHC Sandisk class 4 Video HD

First thing I wanted to test was my SDHC cards and these are left over from my HF100 which I have now sold. The cards I have are 8 gig Sandisk Video HD and they are rated class 4.
Longest test I did with HF100 was 1hr30m shot at 1080p AVCHD 17mbps. Used log & transfer to FCP ... no problems.

Now for the GH1 .. same card and due to less disk space than usual on my mac I cut it short at 1hr 5min. GH1 recorded fine, no problems at 1080p AVCHD 17mbps. Used the same log & transfer to take it into FCP ... took a long time .. and there was no problems. Of note - the total size on the sdhc card for this test was 4.6gig and once it was transcoded to prores it was a 67gig .mov file

So as far as my tests go, I think its fine to use the Sandisk Video HD class 4 speed rating.

Here's a link to the 8 gig card I used, costs about $30 LINK
and they have the same card with 4gig, 8, 16 etc cheapest is $20 LINK

AUDIO SYNC with H4

Well I figured if I'm going to transcode such a huge file I may as well do an audio sync test at the same time. I am using the H4 not the H4n. To save time I did not remove pulldown and I don't beleive this would have made a difference - please tell me if I am wrong. So with the prores file at 29.97 and the timeline at 29.97 the audio was out by 10 frames at the end of the hour.

I think this is good info to know especially as I only own one cam and you never know when someone is gonna want to pay you to shoot a long interview or something.
 
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Thanks for being the guinea pig. It'll be good to save some money on SDHC cards.

Have you tested 60P yet? Wonder if Class 4 can handle that.
 
I saw somewhere on vimeo (I think the Zacuto profile page) where they used the H4n and showed how to sync it with the 5DMkII footage and for some reason (I haven't tried to figure out why yet) they adjusted the audio speed to 99.99%.

Perhaps there is something you need to do that is similar to ensure the audio remains in sync?
 
Isaac_Brody said:
Thanks for being the guinea pig. It'll be good to save some money on SDHC cards.

Have you tested 60P yet? Wonder if Class 4 can handle that.
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Yeh but not a long test. Longest at 60p was 6-8 minutes. Pushed it thru cinetools and dropped into 24p timeline, played beautifully.

Don't mind being the guinea pig as I was planning to run these tests anyway. If the cards from the HF100 hadn't worked I would have shelled out cash for the class 6 (but no point doing that till after testing).

The fact that I can shoot on a $20 4gig card is awesome news to tell a potential client. I think the limit on that card is 45 mins of 1080p.

There are some other tests I did that concern the mounting of the H4 for solo run & gun and in particular the problem of handling noise and lack of a shock mount. For those that haven't read it, the thread for that is here LINK
 
e-steve said:
I saw somewhere on vimeo (I think the Zacuto profile page) where they used the H4n and showed how to sync it with the 5DMkII footage and for some reason (I haven't tried to figure out why yet) they adjusted the audio speed to 99.99%.

Perhaps there is something you need to do that is similar to ensure the audio remains in sync?
Click to expand...

Yep .. the .wav from the H4 was longer.

I used CTRL click on the tiime line counter to convert to frames and it was 117215 frames long.

10 frames out means the .wav should have been 117205 frames long and if you divide it out it comes to %99.991468 ... blah blah

I could have saved myself all this hassle and just watched your vid
(but I am a mistrustful soul ... I like to learn the hard way! )
 
Good for left over cards but seems like no reason not to get class six, cost-co sells two 4gb 15megabyte/second cards at $30 for the pair....or 4x2gb.
 
Whatever the card .. its important to test the hell out of it before showing up on a shoot and disappointing a whole lot people.
Me? ... I like brand name 4gig cards ... and a bunch of them to use in rotation.
 
Regarding removing pulldown and synching with H4n audio

Will the audio from the H4N sync well to pull down removed 1080P? Thats one of the few questions I have with this combo.
 
John Caballero said:
Regarding removing pulldown and synching with H4n audio

Will the audio from the H4N sync well to pull down removed 1080P? Thats one of the few questions I have with this combo.
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I believe that the 10 frame error I saw would have been the same before/after pulldown. As far as a difference between H4 and H4n .. that I don't know as I tested with H4.

e-steve said the zacuto vid shows that they saw the same error rate I saw and they used the H4n

EDIT
either way if you are removing pulldown to get true 24p then you are probably doing narrative film type stuff .. right?
in which case it is unlikely you would need to correct for the error as its usually lots of short takes.
I'm doing 24p narrative and I will not be correcting for the error unless its a shot that goes for 5-6 minutes and has dialog near the end
 
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I believe that the 10 frame error I saw would have been the same before/after pulldown. As far as a difference between H4 and H4n .. that I don't know as I tested with H4.

e-steve said the zacuto vid shows that they saw the same error rate I saw and they used the H4n
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Thanks.

BTW: I just bought this tripod for when I get the GH1. Its pretty smooth for the pans but two cool things about it is first that you can lower it to 11'' and second that about 5 inches bellow the head you can unscrew it and use that portion up for handheld shots. You can put the camera on top a little sideways in between the handle bars, then press the handle bars against your chest and hold the 5'' of tube with your hand. I think is gonna work pretty good. You can take it from tripod to handheld in a minute. It is also very light but sturdy.

http://www.adorama.com/TFV3H.html?searchinfo=voyager+tripod
 
Car3o said:
17mbs/8=2.125MB/s which in theory a Class 2 card could do. Class 4 is 2x the speed necessary to record video.

Class 6 cards from A-data run you $9.00 over at newegg

http://www.newegg.com/Product/Product.aspx?Item=N82E16820211067

People spending money on ultra III's or whatever are either really bad at math or don't mind spending money on unnecessary gear.
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Actually I was testing out old cards .. I haven't bought new cards for a while and had no idea about those prices.

So are A-data cards a reputable brand?
So is this the card that you use, have tested and recommend?
Or did you just go to newegg and search for all class 6 cards and order by price just to prove a point. LINK
 
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J Davis said:
Actually I was testing out old cards .. I haven't bought new cards for a while and had no idea about those prices.

So are A-data cards a reputable brand?
So is this the card that you use, have tested and recommend?
Or did you just go to newegg and search for all class 6 cards and order by price just to prove a point. LINK
Click to expand...

A-data is the memory I use in my PC, kicking 4 gigs of it. Over 2years now?
I had planned on using it on my d90 and will use it with a Gh1.
It wasn't this particular card, but I had one under my wish list and it was only $7, same brand, but they no longer sell it.
Not to prove a point, but to point out to others they don't need to spend money on SanDisk Ultra whatevers.
 
Car3o said:
A-data is the memory I use in my PC, kicking 4 gigs of it. Over 2years now?
I had planned on using it on my d90 and will use it with a Gh1.
It wasn't this particular card, but I had one under my wish list and it was only $7, same brand, but they no longer sell it.
Not to prove a point, but to point out to others they don't need to spend money on SanDisk Ultra whatevers.
Click to expand...

A challenge for you -
buy a GH1 and the $9 A-data cards that you recommend, run a bunch of 1 hour tests and post the results. That way we can all benefit. Good idea no?
 
J Davis said:
A challenge for you -
buy a GH1 and the $9 A-data cards that you recommend, run a bunch of 1 hour tests and post the results. That way we can all benefit. Good idea no?
Click to expand...

Great idea. The cheapo cards are only useful if they've been tested and work fine. Until then I'll stick to the tested Sandisk whatevers.
 
A-data are quite reliable and have used them on the HMC150 and EX1 with K&S adapters. I think I posted that I even accidentally left the adata card in the washing machine and it still worked fine afterwards.
 
J Davis said:
A challenge for you -
buy a GH1 and the $9 A-data cards that you recommend, run a bunch of 1 hour tests and post the results. That way we can all benefit. Good idea no?
Click to expand...

no problemo...i'll even buy a pair of $15.00 basketball shoes and report back how they'll hold up just as good as Nike.

If the cards suck, hell I'll be out a massive 9 bux that would've probably went to some double cheese burgers anyway.
 
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