Transcend and simultaneous tape & card recording...

[Laurence Kingston]

I have a theory that I'm not sure is accurate or not:

The theory is that if you are using a slower 133x card such as the Transcend, that you will get good results if you record to just the card, but not if you record to tape and card simultaneously.

The reason (according to this theory) is that with the slower card, there is a little more buffering time required after each time you stop recording. With both tape and card however, the tape has stopped while the card writing is still buffering and the Z7 will let you start recording again before the buffered write to the card has stopped. This leads to errors on the card but not the tape.

If this theory is true, with a 133x card such as the Transcend 16GB and 32GB, recording to just the card is fine since the camera won't let you start the next clip until after the writing has stopped. It's just when you record to both tape and card and then, just when you are recording in a quick "run and gun" style of quick starts and stops.

When I get some time I'll start testing this theory out (the next few days are kind of busy editing wise).

Does anyone else think this might be the case or am I off base in this idea?

[Marshall Levy]

Yes, that can be deemed correct. I alluded to this in several other posts and is given based on the read/write/recordation process of the data to the card and the applicable buffering in both saving the file and queing for the preceding recordation.

[Laurence Kingston]

This sounds like the kind of thing that might be fixable with a firmware update.

In my head I see something like this happening:

The Z7 is in standby. In card only mode, from there it goes into record when you hit the red button, and back into standby when it gets a message from the card writer telling it the buffering is over. In tape it gets the same message from the tape transport. In dual record mode, it might be still just getting the message from the tape.

A firmware update could either wait messages from both the tape transport and card writer before going into standby, or it could just wait for a message from the card writer since it is likely to be slower.

On the other hand, with a fast 306x card, maybe the card writer is done before the tape transport is finished. I don't have a faster card so I can't test this.

[Marshall Levy]

It shouldn't increase the time difference in syncing between tape and card based on a 133x, 306x card, etc. I saw no difference at all when I tested all the cards a few months back, and even according to Sony, there shouldn't be any deviation.

Who knows. Too bad there are so many discrepencies with this camera.

It works well with tape, it works well with card, but together, who knows.

[Hedley Wright]

It might explain why I've had the occasional failure to record to cf although the camera has recorded the clip to tape

[Laurence Kingston]

There are two different ways to setup simultaneous record to CF card and tape.

One is to use the Z7 as it comes set from the factory with the Z7 in tape only mode and the card writer unit in "follow" mode. This is the same way you would use the card writer with a camera not designed for it like a HVR-Z1.

The second is to put the card reader in the proper mode for the Z7 and S270 and put the Z7 in the mode where it records to both card and tape.

When you work with the camera these modes feel quite different. In the first, you have one single record indicator on the camera screen and viewfinder and exactly the same thing should be recorded to both tape and CF card.

In the second, you have two record indicators in the camera viewfinder and screen and you can actually see the CF card record indicator going into record first.

It is entirely possible that with slower (133x) cards, the first method of doing a dual record is more reliable than the second.

[Brian Standing]

I've been reading the manuals for the Z7 and the CF recorder in anticipation of buying a Z7 sometime next month.

I'm wondering if turning on the CF Recorder's "pre-buffer" feature might help this problem of the CF recorder starting after the tape does. According to Sony, this feature is intended to capture a few seconds BEFORE you press the record button.

Would this help bring the CF recorder up to "speed" a bit more quickly? Has anyone tried this out?

[Laurence Kingston]

I don't believe the problem is the CF card "comming up to speed" but rather it starting to try to record again before the last clip has finished buffering to the card.

[Brian Standing]

Ahhh.... I see. Sounds like a return to the old techniques of film shooting might be appropriate. Cameramen may have to yell out "Speed!" after a few seconds between takes so the CF card can catch up.

Is it common for folks to hit the record button on and off again in very rapid secession? It seems like under normal circumstances, there's at least several seconds between takes. Does this tape/CF sync problem rear it's head even if you wait 5-7 seconds before pressing the RECORD button again?

[Kevin Walsh]

Has anyone tried the new Transcend 16gb 300x card?

[Laurence Kingston]

Here is a link to the new Transcend 16GB card:

http://www.transcendstore.com/ts16gcf300.html

or here for a better price:

http://www.newegg.com/Product/Produc...end-_-20208419

[Steve Mullen]

Originally Posted by Laurence Kingston

I don't believe the problem is the CF card "comming up to speed" but rather it starting to try to record again before the last clip has finished buffering to the card.

Turning on PRE-BUFFER might let the NEW data flow into the buffer while the PREVIOUS data was still being written to the card.

Ideally you want a card with a higher speed than necessary to simply write data from the camera. That would enable it unload the buffer while still writing.

It seems Sony only tested it's own cards -- which is perfectly reasonable. And, perhaps the reason their cards are expensive is Sony designed them to meet these types of demanding applications. (Speed testing is not the same as worst case testing.) Perhaps the reason they are not yet available is that Sony found it needed to enhance its design after testing.

The division making and selling camcorders has no influence on the division making media. It's not unknown for divisions to get out of sync with release dates. Anyway -- HDV is a tape format and you can still use your camcorders -- so might Sony reason. A few months wait is not going to cause the tapeless revolution to not occur.

[William J. Wirth]

Originally Posted by Laurence Kingston

I don't believe the problem is the CF card "comming up to speed" but rather it starting to try to record again before the last clip has finished buffering to the card.

From my experience, this seems to describe exactly what I am experiencing. I have 3 cards, Transcend 16gb 133x, Sony 8gb 306x and a Kingston 8gb 266x. I always record to tape and card.
Frequently, when I do short takes (< 5 seconds), the clip will not be recorded. In addition, the next clip of any length to be recorded to the card will be, apparently, written incorrectly. What I mean, is that when I import into Premiere, Premiere will determine the clip speed to 119.88fps or 59.94fps. The clips recorded to tape are always just fine.
So an explanation of a clip not being completely written to the CF card, or certain bits not set, makes sense to me. Card speed may well be a factor but it doesn't seem likely in my case since it happens to me with all the cards above. It certainly is curing an itchy trigger finger.

[Gary Nattrass]

I tend to find that the CF goes into record first and they I wait a long time for the tape deck to come out of standby. Once it is out of standby both units seems to go into record virtually at the same time.
As said it is good top have the twin rec indicators in the viewfinder as that you can see that all is OK, I have done some home video jobs and I just used the CF on its own and it was really quick.

[Zoltan Lorincz]

I have worked with sync. rec. several times and had no problems the synchronization problems can come from reaction time of media. When the card is not ready and the tape is then the camera will record only on tape until the next clip. When the card is ready and the tape not the card will start just when the tape becomes ready. You can lost the clip from the cart when you make fast stop start one after the other. If you are careful with this things you will have no problems. I worked in sync rec. tens of hours with no problems.