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Old July 25th, 2010, 08:59 AM   #1
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prebuffer too short

Maybe a question for Dan Keaton.

According to the manual prebuffer should be 7 seconds with bit rates of up to 100Mb/s and 4 seconds with bit rate of 140 Mb/s. My nanoflash has a prebuffer of (sometimes just short of) 4 seconds at 140 and at 100 Mb/s. A prebuffer of 6-7 seconds is realized only at 80 Mb/s or lower. This means that 7 seconds is not possible with I-frame anyhow. Is this correct? Or am I doing something wrong?

Using an EX-3, cards SanDisk 32 60MB/s and the latest firmware 1.6.29 on the nano.Checked it by filming the second hand of a clock, gave sufficient time between attempts to fill the buffer.

Last edited by Cees van Kempen; July 25th, 2010 at 11:28 AM.
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Old July 25th, 2010, 11:31 AM   #2
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Dear Cees,

Thanks for pointing out the discrepancy.

We will test this and either fix it, or adjust the manual.
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Old July 25th, 2010, 11:35 AM   #3
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Dear Dan,

Thanks for your prompt reply. No need to mention I would prefer to have it fixed, instead of manual adjusted.

Is there a chance anyway that the length of the prebuffer will be increased in future?

Dan, please also see my other post of today, regarding incidental faulty clip dimensions.
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Old July 26th, 2010, 10:33 AM   #4
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I'd be willing to pay a premium (extra $$) for a Nano a larger pre-buffer with a programmable size. 15-30 seconds at high bitrates would be preferable. Often, I'm covering wildlife with sparse action and see this option as a great editing time and space saver.

Also, I'd prefer a normal-sized HDMI connectors. I find myself using the HDMI size adapters, and the subsequent lack of a snug connection demands additional attention to cable placement.

Last edited by Gints Klimanis; July 26th, 2010 at 12:41 PM.
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Old July 26th, 2010, 11:35 AM   #5
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I fully agree with Gints,

Any second extra prebuffer will be very valuable. It is for this reason I also find it very important to be able to shoot I-frame with the 'promised' 7 seconds (@100Mb/s). 4 seconds is very short in wild life action.

Would really like to know if improvements on the prebuffer (longer) might be expected in future.

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Old July 26th, 2010, 11:36 AM   #6
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I meant wildlife action, instead of wild life action :-)
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Old July 27th, 2010, 03:03 AM   #7
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Quote:
Originally Posted by Gints Klimanis View Post
Also, I'd prefer a normal-sized HDMI connectors. I find myself using the HDMI size adapters, and the subsequent lack of a snug connection demands additional attention to cable placement.
Hello Gints,

I used to have the same issues with HDMI size adapters. Now I use an HDMI to mini HDMI cable, (like this one http://www.bhphotovideo.com/c/product/481677-REG/Sony_VMC_15MHD_HDMI_Male_to_Mini.html ) and disconnections become scarces.

However, HDMI even at normal size, is not a very reliable connection system. I have even loss of video signal between my DVD player and LCD TV sometimes!
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Old August 6th, 2010, 06:09 AM   #8
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Quote:
Originally Posted by Dan Keaton View Post
Dear Cees,

Thanks for pointing out the discrepancy.

We will test this and either fix it, or adjust the manual.
Dear Dan,

I have noticed you adjusted the manual. Any chance of increasing the prebuffer length, or at least to increase 100Mb/s to 7 seconds? Now the max with I-frame is 4 seconds and in practice it often is even a bit shorter.
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Old August 6th, 2010, 06:15 AM   #9
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Dear Cees,

The size of the Prebuffer is limited by the amount of memory we can devote to the Prebuffer.

Four seconds of video at 100 Mbps uses a lot of memory.


Do you have one of our Remote Controls? This would allow you to have the Record Switch, with Tally Light, in your hand, ready to start recording within the Prebuffer time limit.
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Old August 6th, 2010, 06:27 AM   #10
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Dan,

No I don't have this accessory. I tried to get information about possibilities like that on this forum one day, but did not get the information I was looking for. Alas you accessory page on internet is also still under construction. Where can I find more information about this product? How to get it in The Netherlands? And (I am in the questioning mode :-) ), can you use it in combination with TC, so you can easily change from using an EX3 handheld/shoulder (TC required since on/of button on the lens) to tripod (with remote).

Cees
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Old August 6th, 2010, 06:48 AM   #11
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Dear Cees,

If you ask your dealer, they can get this "Remote Control with Tally Light and Timecode cable" from Symbiosis, our European distributor.

Or you can look on www.nanoFlash.net, under "Remote Controls" to see this accessory, and others.

The nanoFlash has a menu option, System|Trigger, which allows for 8 different ways to trigger the nanoFlash to start recording.

At this time, we do not have a option for "Trigger on Incrementing Timecode" or "Remote Control".

It is very easy to change this option to "Trigger on Incrementing Timecode" when you go handheld.
(If this is the last menu option that you used, then when you return to the menu, this will be the menu option displayed. Thus, you can change back and forth in a few seconds.)
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