Recording SD or HD to Compact Flash at DVinfo.net

Pavan Moondi · July 27th, 2010, 10:49 AM

Using the Z7U.

I'm trying to minimize how many Compact Flash cards I need for shooting longer events so I decided to shoot SD/DV instead of HDV.

I made the necessary changes in the camera, but when I insert the 16GB card I have, it says I can still only record 73 minutes of footage?

I read in a review that you can only record 73 minutes of footage to a 16GB CF card, regardless of whether its DV or HDV. Is this correct? If so, how on earth is this possible? 16GB is 16GB and DV should have a significantly smaller file size, no?

Bernd Eller · July 27th, 2010, 11:52 AM

I guess, it´s not what you want to hear, but your camera and cards are behaving exactly as they should. DV and HDV2 (1080i) share identical bitrates, so you get the same length of recording.

Adam Gold · July 27th, 2010, 01:11 PM

Quote:

Originally Posted by Pavan Moondi

DV should have a significantly smaller file size, no?

No. HDV and DV have different compression schemes but the file sizes are identical.

Pavan Moondi · July 27th, 2010, 01:30 PM

appreciate the responses. Disappointed for sure, but thankfully I found a place nearby that has reasonably priced compact flash cards, so I suppose I might as well film in HDV.

Charlie Steiner · August 10th, 2010, 04:07 PM

get a 64GB --- well worth the price, over 4.5 hours of video

Zach Love · August 11th, 2010, 01:24 AM

They're both 25Mbps. DV was invented in the '90s along with DVCam & DVCPro, all 25Mbps.

When things started going HD, HDV was created nearly a decade later. A lot of time in the digital world & they were able to create a completely new codec in HD res but still 25Mbps.

While HDV has many limitations & faults of a codec, (4:2:0 color space & Long GOP compression), the biggest selling point is that it uses the same tapes as DV (or miniDV) & since it is at the same bit rate (25Mbps) & tape speed as DV, it was easier for manufactures & users to transition from DV to HDV & back to DV.

Now if you get a AVCHD camera you're file sizes are going to be even smaller (depending on the compression you choose). So the statement that "HD = bigger file sizes" isn't always true, what is true is the bigger the bit rate, the larger the file per min.

Progress can always be confusing, especially when it changes the rules of how things used to be.

July 27th, 2010, 10:49 AM	#1
Pavan Moondi New Boot Join Date: Jan 2010 Location: Toronto, ON Posts: 11	Recording SD or HD to Compact Flash Using the Z7U. I'm trying to minimize how many Compact Flash cards I need for shooting longer events so I decided to shoot SD/DV instead of HDV. I made the necessary changes in the camera, but when I insert the 16GB card I have, it says I can still only record 73 minutes of footage? I read in a review that you can only record 73 minutes of footage to a 16GB CF card, regardless of whether its DV or HDV. Is this correct? If so, how on earth is this possible? 16GB is 16GB and DV should have a significantly smaller file size, no?

August 10th, 2010, 04:07 PM	#5
Charlie Steiner Regular Crew Join Date: Jul 2008 Location: New Orleans, LA Posts: 66	up the ante get a 64GB --- well worth the price, over 4.5 hours of video

August 11th, 2010, 01:24 AM	#6
Zach Love Major Player Join Date: Jul 2006 Location: Chicago, IL Posts: 944	They're both 25Mbps. DV was invented in the '90s along with DVCam & DVCPro, all 25Mbps. When things started going HD, HDV was created nearly a decade later. A lot of time in the digital world & they were able to create a completely new codec in HD res but still 25Mbps. While HDV has many limitations & faults of a codec, (4:2:0 color space & Long GOP compression), the biggest selling point is that it uses the same tapes as DV (or miniDV) & since it is at the same bit rate (25Mbps) & tape speed as DV, it was easier for manufactures & users to transition from DV to HDV & back to DV. Now if you get a AVCHD camera you're file sizes are going to be even smaller (depending on the compression you choose). So the statement that "HD = bigger file sizes" isn't always true, what is true is the bigger the bit rate, the larger the file per min. Progress can always be confusing, especially when it changes the rules of how things used to be. __________________ Nothing says you're a serious video maker like S-VHS

July 27th, 2010, 11:52 AM	#2
Bernd Eller Regular Crew Join Date: Jul 2007 Location: Upper Franconia, Germany Posts: 60	I guess, it´s not what you want to hear, but your camera and cards are behaving exactly as they should. DV and HDV2 (1080i) share identical bitrates, so you get the same length of recording.

July 27th, 2010, 01:30 PM	#4
Pavan Moondi New Boot Join Date: Jan 2010 Location: Toronto, ON Posts: 11	appreciate the responses. Disappointed for sure, but thankfully I found a place nearby that has reasonably priced compact flash cards, so I suppose I might as well film in HDV.