|
|||||||||
|
Thread Tools | Search this Thread |
January 6th, 2010, 06:58 PM | #1 |
Major Player
Join Date: Sep 2008
Location: East Bay Cali
Posts: 563
|
What is the Hardest Test for "overcranking" EX1r ?
I now Want to test my various SDHC to SxS memory adapted Flash Chips, to see where they or the adaption might cause a problem, on the EX1r .
What is the worst that i can throw at it? Resolution, frame rate , Alternate adjustable frame rate , I or P . Then I assume i throw at it the worst mess of a moving picture, with what else? lots of Contrasting images, lots of color changes? Break my memory. It seemed to me that 720 60p is the fastest , but i dont understand "overcranking" beyond the available maximums because nothing can be set OVER the max speeds it can already video at?? Did EX-1/3 Cameras do the STOCK 720 60p with the adapted chips??? or is there something different about being "overcranked" ? Did the data rate on "overcranking" exceed the 35Mb/s or does having the cams IN overcrank mode allow for higher data rates?
__________________
----------------sig----------------- Re-learning everything all over again, one more time. Last edited by Marty Welk; January 6th, 2010 at 08:25 PM. |
January 6th, 2010, 09:00 PM | #2 |
Inner Circle
Join Date: Feb 2004
Location: Brooklyn, NY, USA
Posts: 3,841
|
All XDCAM EX standard frame sizes and frame rates are 35mbps VBR whether 720p60 or 1080p24.
Overcranking can push the data rate to about 87.5mbps. That would be 720p24/60fps. I'm hearing the top SDHC overcrank is MxM card with ATP ProMax SDHC cards at something around 720p24/50 sustained without a Media Error but I thought I heard someone claim higher. Sandisk Extreme Class 10 might go to that rate as well. Overcranking records at such high data rates because the resultant file will play back at the base frame rate at 35mbps. In other words 24/60 records at 87.5mbps so it'll play back at 24fps at 35mbps. 24/48 would be 70mbps 30/60 would be 70mbps 25/50 would be 70mbps They are all recording twice the base framerate. 24/60 is the widest disparity between base framerate and recording so that is 87.5mbps. 24 goes into 60 2.5 times. 35mbps x 2.5 = 87.5mbps. |
January 6th, 2010, 09:31 PM | #3 |
Major Player
Join Date: Sep 2008
Location: East Bay Cali
Posts: 563
|
great that made a whole lot of sence.
so the 24 frame rate is using the 35Mb/s still then cranking THAT up, the data rate keeps climbing. now i have something that will really break it.
__________________
----------------sig----------------- Re-learning everything all over again, one more time. |
January 6th, 2010, 10:23 PM | #4 |
Major Player
Join Date: Sep 2008
Location: East Bay Cali
Posts: 563
|
My transcend 16g chip, which always tested out at the full class 6 on the computer, and has always worked wonderfully. Coped with 1280 60/24fps even through vast color changes, and wild camera work.
I tested to see if there really was way more data and it was lots more data. then ran it for long periods of time, to be sure. Then i got to thinking (oh nooo) I am always trying to get less compression going on, and increase the 35Mb/s recording, so when i film fast moving stuff i dont have compression problems. and logically there i am Filming 60fps at a Much higher data rate. and the only thing is the File is tagged for playback at 24fps, there really is 60fps of normal motion there? If i play this file back at 60fps edit it at 60fps and output it as 60i after interlacing it. then dont i have a much higher data rate then they intended/allowed? a cheap trick to have a Mini Nano right there in the camera itself? or to simplify the process and double the data rate, set it for 720-30, overcrank that to 60 have 70Mb/s data, and 2X speed it later, sounds easy, doesnt it always :-)
__________________
----------------sig----------------- Re-learning everything all over again, one more time. |
January 6th, 2010, 11:52 PM | #5 |
Major Player
Join Date: Sep 2008
Location: East Bay Cali
Posts: 563
|
well chock that one up as Stupid idea #7526389
it didnt take me long to realise there is no Audio on an overcrank, even if i am using external audio i am not going off without a audio sync signal /backup audio. i knew it was to easy.
__________________
----------------sig----------------- Re-learning everything all over again, one more time. |
January 7th, 2010, 09:59 AM | #6 |
Major Player
Join Date: Nov 2007
Location: Stockholm, Sweden
Posts: 462
|
Marty,
I accidently discoverd a couple of weeks ago that the USB-bus of the EX1r seems to allow higher data speeds and thus higher overcranking than the old EX1 on SDHC media. Your results seem to confirm this. See my original thread here: http://www.dvinfo.net/forum/sony-xdc...overcrank.html I'd be interested in results from more people with EX1R cameras and different combinations of SDHC-cards and adapters. Is the bottleneck really gone? |
January 12th, 2010, 05:57 PM | #7 |
Regular Crew
Join Date: Dec 2009
Location: Edmonton, Canada
Posts: 61
|
I have an EX1 with the MXR using the Scandisk Ultra class 4 16GB cards. London Drugs had a sale at the time for 65.00 each. I bought 6 of them. I set up the camera at 720P 48 and all cards passed. Then I thought about the possibility of the variable bitrate that may be at play. I did the test again but this time I fairly quickly panned the camera back and forth about 45deg. This time only three cards passed the test of being stable indefinately. The other three failed somewhere between 10 and 30sec. Took three back but didn't push my luck with onother three. Does this make sense?
Larry |
| ||||||
|
|