If SDHC card is 20mps, and camera is 24mps recording. Hows that working? at DVinfo.net

Go Back   DV Info Net > Panasonic P2HD / AVCCAM / AVCHD / DV Camera Systems > Panasonic LUMIX G / GF / GH / GX Series

Panasonic LUMIX G / GF / GH / GX Series
4K and AVCHD on a Micro Four Thirds system camera with interchangeable lenses.


Reply
 
Thread Tools Search this Thread
Old November 27th, 2011, 06:58 PM   #1
Major Player
 
Join Date: Sep 2004
Location: North Hollywood, Atlanta
Posts: 437
If SDHC card is 20mps, and camera is 24mps recording. Hows that working?

I just realized my GH2 SDHC memory card is only a 20mps card. IF the GH2's 24p mode records at 24mps then its data rate exceeds the memory card. Yet i am able to record video w/o any warnings. I wonder though, how this is working? Is the camera making a sacrifice?
__________________
Tyson X
Tyson Persall is offline   Reply With Quote
Old November 27th, 2011, 08:02 PM   #2
Major Player
 
Join Date: May 2007
Location: Alpharetta, Georgia, USA
Posts: 758
Re: If SDHC card is 20mps, and camera is 24mps recording. Hows that working?

The answer is most cards from a reputable manufacturer exceed the advertised specification. To put it another way, the advertised specification is the absolute MINIMUM that the card will do. The manufacturer has built in a margin of error. So while skating on the edge, so far the card has been fast enough to let you get away with it :-) But now that you realise that is the situation, are you comfortable with that?
Bill Koehler is offline   Reply With Quote
Old November 27th, 2011, 08:18 PM   #3
Major Player
 
Join Date: Sep 2004
Location: North Hollywood, Atlanta
Posts: 437
Re: If SDHC card is 20mps, and camera is 24mps recording. Hows that working?

Thanks. Nice answer. Good to know... I was just wondering if it was dropping frames to accomplish the recording or something. I did notice that when shooting RAW stills after 2 or 3 shots it freezes up for about 20 seconds while saying writing to card. Guess thats where a faster card helps for sure.
__________________
Tyson X
Tyson Persall is offline   Reply With Quote
Old November 27th, 2011, 08:32 PM   #4
Inner Circle
 
Join Date: Aug 2006
Location: Efland NC, USA
Posts: 2,315
Re: If SDHC card is 20mps, and camera is 24mps recording. Hows that working?

Look carefully and you will see the card is rated at 20mB/sec not 20mb second. 20mB/sec is about 160mb/sec which is much greater than what the camera requires.
__________________
http://www.LandYachtMedia.com
Chris Medico is offline   Reply With Quote
Old November 27th, 2011, 09:18 PM   #5
Inner Circle
 
Join Date: Dec 2004
Location: Arlington, TX
Posts: 2,230
Re: If SDHC card is 20mps, and camera is 24mps recording. Hows that working?

Yes, megabits and megabytes. The codec is in megabits (1/10th the size)
Tim Polster is offline   Reply With Quote
Old December 3rd, 2011, 12:51 PM   #6
Regular Crew
 
Join Date: Sep 2009
Location: Fort Wayne, IN (USA)
Posts: 85
Re: If SDHC card is 20mps, and camera is 24mps recording. Hows that working?

Quote:
Originally Posted by Tim Polster View Post
Yes, megabits and megabytes. The codec is in megabits (1/10th the size)
Actually, 1/8 the size. A byte is a group of 8 bits.
__________________
Blog
Jordan Nash is offline   Reply With Quote
Old December 4th, 2011, 09:01 AM   #7
Inner Circle
 
Join Date: Dec 2004
Location: Arlington, TX
Posts: 2,230
Re: If SDHC card is 20mps, and camera is 24mps recording. Hows that working?

Yeah but 1/10th sounds better! I was rounding to make a point but that is wrong as it is important to get the facts straight.
Tim Polster is offline   Reply With Quote
Old December 5th, 2011, 05:04 PM   #8
Regular Crew
 
Join Date: Sep 2009
Location: Fort Wayne, IN (USA)
Posts: 85
Re: If SDHC card is 20mps, and camera is 24mps recording. Hows that working?

Quote:
Originally Posted by Tyson Persall View Post
I just realized my GH2 SDHC memory card is only a 20mps card. IF the GH2's 24p mode records at 24mps then its data rate exceeds the memory card. Yet i am able to record video w/o any warnings. I wonder though, how this is working? Is the camera making a sacrifice?
Don't forget that your recording is compressed, so perhaps it's 24Mbps when played out, but less than that as compressed data?
__________________
Blog
Jordan Nash is offline   Reply With Quote
Old December 5th, 2011, 05:24 PM   #9
Inner Circle
 
Join Date: Aug 2006
Location: Efland NC, USA
Posts: 2,315
Re: If SDHC card is 20mps, and camera is 24mps recording. Hows that working?

The video is played out uncompressed via HDMI. At 1080p24 the data rate is about 100MB/sec (800Mb/sec). The rate of 24Mb/sec is the compressed rate.
__________________
http://www.LandYachtMedia.com
Chris Medico is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Panasonic P2HD / AVCCAM / AVCHD / DV Camera Systems > Panasonic LUMIX G / GF / GH / GX Series

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 07:55 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network