New to this forum, have questions regarding SDHC cards

[K.C. Kennedy]

1. We just purchased a new NX5u and the question is regarding SDHC cards. I was picking brains of a B&H rep for a minute and he told me that 24mbps is an absolute minimum for NX5u. I saw Transcend cards which are 20mbps and I think people here use them without problems. Please, confirm.

2. Are there other less expensive options besides 32gb Transcend for $108 from B&H?

3. We are producing a small talk show from our house and the local cable channel haven't switched to HD yet, so we give them all the footage in SD. So, for the time being, what are my options with SDHC cards on a budget to shoot in SD mode?

Thank you all in advance.
KC.

[David Wayne Groves]

NewEgg has the Transcend SDHC 32Gig class 6 cards for $99.00 with free shipping, I have 2 that I use with my HDR AX2000...They work perfectly on all my High Def footage needs.....

[K.C. Kennedy]

Dave, thank you for your quick reply. B&H has a class 10 transcend 32gb for $108, doesn't sound too good to go down to class 6 for $9.

[Junior Pascual]

Transcend 32 GB, class 6 on Amazon.com for $89.00, free shipping.

[Gabroo Singh]

Adorama has the 16gb Lexar Class 4 for $24.95

LSD16GBSBNA060 Lexar 16GB 60x Platinum II Series, Secure Digital High Capacity (SDHC) Memory Card

[K.C. Kennedy]

and class 4 will support HD recording? B&H rep told me minimum I need is class 10... I'm confused.

[Ben Moore]

You don't need class 10 cards, class 4 and higher all work. I have all class 4's and have recorded at the highest bit rates many times with no issues. Don't confuse MB with Mbps, it sounds like B&H is using this confusion to upsell more expensive cards.

Ben


Also see this post:

http://www.dvinfo.net/forum/sony-nxc...s-hxr-nx5.html

[Junior Pascual]

Check you camcorder's manual. For the HXR-NX5/HDR-AX2000, class 4 cards are good enough.

[Heath McKnight]

On the local cable channel still on SD--shoot and edit in HD and output to SD, so when they do go HD, you'll have archived footage already in hi def.

Heath

[Jay West]

Maybe there is some confusion over acronyms? Sometimes you have to read closely to see whether they are describing MB (megabytes) or mb (megabits). 20 "MBps" is a lot more than 24 "mbps"

The cards are 20 MBps, sometimes abbreviated as 20 mBps, and which refers to megaBytes per second. Each "Byte" equals 8 "bits."

The NX5 records AVCHD at up to 24 Mbps (or mega-bits per second). To convert that to "megaBytes" you divide by 8. So 24 Mbps AVCHD is actually 3 MBps.

Incidentally, 24 Mbps is the "maximum" AVCHD recording rate for the NX5. (This is the "FX" setting.) The "absolute minimum" rate is the "LP" mode at 5 Mbps. It seems to me that the B&H rep may have been expressing a personal opinion that you should always use the FX settings (24 mbps) with the NX5 to get the best pictures or he/she may have been saying that a 20 mBps card is the absolute minimum card to use when shooting FX AVCHD on the NX5.

For shooting to SD, you've got basically two options with the NX5. One is to record at HQ 480/60i mode (9 Mbps Mpeg 2) for standard def video. The other is to shoot in FX AVCHD as Heath recommended (as do I.) Remember when shooting to give due respect to SD 4:3 framing if that is your delivery format. You output your edited HD footage to whatever format the cable company wants (DVD/Mpeg2? AVI or Quicktime file?)

[George Peterson]

Another vote for class 4's. Been using them for a year with no problems at all. HD max rate on Canon hf-s11 and panny tm700.

[Ben Moore]

So to sum it up, a class 4 card has a minimum transfer rate of 4MBps. Mulitiply that by 8 and you get 32Mbps which is faster than the 24Mbps the NX/AX cams record, so class 4 is enough with some left over :-)

[Cristian Adrian Olariu]

If you observe the LED's in the back, the recording is not happening in realtime. The camera records in a memory buffer a few seconds then transfers it on the cards. This means that the transfer speed is actually bigger than 24mbps. So if the cards have a bigger class leads to quicker transfer speeds (up to maximum bandwidth allowed by the components of the camera) and less usage of the cards that could mean less possibility of cards failures. I use only MS Pro Duo and I noticed that the LEDs are red much shorter time than green.

[Arkady Bolotin]

That’s absolutely correct. To secure a constant writing speed (necessary for programming memory cells of a memory card) camcorders use a buffer. If the memory card’s writing speed is not adequate, the buffer overflow may happen which would lead to dropouts in video recording or a complete loss of information.

The NX5/AX2000 buffer size is about 9 MB, and at the highest image quality setting it’s date rate is 3 MB per second. Therewithal, speed measurement for a class 6 memory card is 6 MB/s (for the class 4 it will be 4 MB/s correspondingly), therefore, it seems quite all right to use such cards in the NX5/AX2000.

And most of the time, it will be so. However, it’s important to remember that speed measurement is based on the best fragmented state where no memory card is occupied. Heavy fragmentation can reduce write speeds, consequently higher SD card speeds help compensate for fragmentation.

Practically this means that if you never erase recorded clips on the fly and clean up your memory card each time by erasing all the clips at once, you probably will be okay with the class 6 (or even with the class 4).

[Tom Hardwick]

By, 'erasing all the clips at once' you mean reformatting the card in camera, right?