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alarch
06-08-2011, 07:58 AM
Hello,
Are SDHC cards class10 at 20mbps suficient for 50 or 60p fullhd?
(technically I should not think so ...)
Do we have to go for sandisc extreme pro at 45mps or do someone know of any other afordable cards

And what time do we get for a 16 or a 32giga bite card?

Stephen Mick
06-08-2011, 08:04 AM
I shot 60-frame 1080p to my Class 10 Panasonic Gold SD cards without a problem. I think my 16GB cards could hold around 100 minutes of 1080/24p material.

ectobuilder
06-08-2011, 08:23 AM
Hello,
Are SDHC cards class10 at 20mbps suficient for 50 or 60p fullhd?
(technically I should not think so ...)
Do we have to go for sandisc extreme pro at 45mps or do someone know of any other afordable cards

And what time do we get for a 16 or a 32giga bite card?

First off, Class 10 cards are rated to give a MINIMUM sustained transfer rate of 10 MB/s. It is IMPORTANT to note that the capital 'B' signifies "BYTES" not "bits". A lower case 'b' is bits. There are 8 bits in 1 Byte (most codecs are spec'd in bits per seconds rather than Bytes per second, more on this later).

Now most Class 10 cards will deliver a burst of 20 MB/s some as high as 45 MB/s. However don't be fooled by these specs as the reason why you are on this forum thread is likely because you have an NXCAM or a camcorder that records to AVCHD.

Currently the official spec on AVCHD is that it will top out at 24Mb/s (that's bits NOT Bytes). With the FS100 it has extended to 28Mb/s. Therefore in Bytes that's 24/8 = 3MB/s or 28/8 = 3.5MB/s.

Therefore is Class 10 adequate? I think so, since 10MB/s is greater than 3MB/s and 3.5MB/s.

Take note that the newer SDXC cards are available now, and are backwards compatible to SDHC, I recommend SDXC over SDHC for the increased capacity. To ensure compatibility, just make sure your camcorder can read it (i.e. it uses the exFat format, therefore make sure your post-production computer can read it too). SDXC takes SDCards beyond the 32GB capacity limit and takes it all the way to 2TB. By default they all appear to come in Class 10 only. Having said that I'd recommend the Lexar Professional line of SDCards. These offer excellent bang for buck. They currently have 16GB, 32GB, 64GB and 128Gb. I have the 64GB (for $130 on bhphoto) and it works great.

jetswing
06-08-2011, 11:06 AM
Therefore is Class 10 adequate? I think so, since 10MB/s is greater than 3MB/s and 3.5MB/s.

If you shoot in S&Q Motion mode, it will have significantly higher throughput since the playback is 24Mbit/sec at the FINAL playback speed, which means it's written at 60Mbit/sec.

Regardless, the manual states that class 10 or higher card is needed for HD recording.

ectobuilder
06-08-2011, 11:38 AM
If you shoot in S&Q Motion mode, it will have significantly higher throughput since the playback is 24Mbit/sec at the FINAL playback speed, which means it's written at 60Mbit/sec.

Regardless, the manual states that class 10 or higher card is needed for HD recording.

Still more than enough. Remember, the minimum sustained transfer rate for Class 10 is 10MB/s. That is equivalent to 80Mb/s (Mbps). So it is still higher than the 60Mbps for S&Q.

Just out of curiousity, how is the 60Mb/s calculation done?

cheezweezl
06-08-2011, 11:57 AM
I'm using transcend class 10 cards. 16gb is $26 on amazon.

speedracerlo
06-08-2011, 01:19 PM
i got a 32gb sandisk extreme class10 30MB/s for $90

ectobuilder
06-08-2011, 01:21 PM
i got a 32gb sandisk extreme class10 30MB/s for $90

Pretty much overkill, first off 30MB is = 240 Mbps. No device that uses SDXC/SDHC uses that much bandwidth, just CF or SSD.

Secondly 30MB/s is burst speed I believe not sustained. Oh well 32GB is 32GB I guess.

Tony Hernandez
06-08-2011, 04:46 PM
If you shoot in S&Q Motion mode, it will have significantly higher throughput since the playback is 24Mbit/sec at the FINAL playback speed, which means it's written at 60Mbit/sec.
.

Thats not true. At 60P data is 28Mb/sec. (28Mbps), yes it means less quality per frame (may be a very litle as for viewable notice, but for sure on data), than recording at 24p.

daihard
06-08-2011, 06:16 PM
Be carful though, some cards are actually stating max rates. This usually means read rates and not always write speeds. That said, almost any class 10 is more then enough, as they are rated by sustained WRITE speeds.

nyvz
06-08-2011, 09:06 PM
Thats not true. At 60P data is 28Mb/sec. (28Mbps), yes it means less quality per frame (may be a very litle as for viewable notice, but for sure on data), than recording at 24p.

That's not true that that's not true. :P

at 1080p60 data is 28Mbps, yes, but at 60fps S&Q recording to 1080p24 24Mbps, it is 60Mbps.

ectobuilder
06-09-2011, 12:40 AM
That's not true that that's not true. :P

at 1080p60 data is 28Mbps, yes, but at 60fps S&Q recording to 1080p24 24Mbps, it is 60Mbps.

How is this being calculated?

cheezweezl
06-09-2011, 04:20 AM
How is this being calculated?

like this. normal 24p FX is 24Mbps. when you overcrank in S&Q mode, it maintains the 24Mbps, based on 24p. So if you overcrank to 30fps, it records at 30Mbps. 60fps is 60Mbps. That way when the footage is slowed down to 24p, you still have a 24Mbps stream.

So recording 28Mbps 1080/60p is NOT the same as recording 24Mbps 24p, and overcranking to 60. Overcranking is much better quality than native.

Think of it like this. This is not how the data is spread out under normal shooting, but if every frame was equal then....

24P 24Mbps = 1Mb per frame.
60P 28Mbps = .47Mb per frame.

this is why you may use a class 4 SD card for normal shooting, but S&Q requires a class 10 card. It's in the manual.

ectobuilder
06-09-2011, 05:02 AM
like this. normal 24p FX is 24Mbps. when you overcrank in S&Q mode, it maintains the 24Mbps, based on 24p. So if you overcrank to 30fps, it records at 30Mbps. 60fps is 60Mbps. That way when the footage is slowed down to 24p, you still have a 24Mbps stream.

So recording 28Mbps 1080/60p is NOT the same as recording 24Mbps 24p, and overcranking to 60. Overcranking is much better quality than native.

Think of it like this. This is not how the data is spread out under normal shooting, but if every frame was equal then....

24P 24Mbps = 1Mb per frame.
60P 28Mbps = .47Mb per frame.

this is why you may use a class 4 SD card for normal shooting, but S&Q requires a class 10 card. It's in the manual.

How did you conclude that in S&Q mode, there is a 1-to-1 relationship between frame rates and data rate (i.e. 1fps = 1megabit)?

cheezweezl
06-09-2011, 05:06 AM
well there isn't a 1:1 ratio really. it's actually variable bit rate and is content dependent. but my point is that is maintains it's relative bit rate when overcranking. so that means 24Mbps at 24fps equates to 60Mbps at 60fps in S&Q mode. this is an old issue that came up when the ex1 was first released. it was a debate between overcranking to 60fps in 720p/24 mode, or just shooting 720p/60 and slowing in post. same principle applies here...

MazingerZ
06-09-2011, 06:13 AM
You can test this, record for 10 seconds in both modes. Check the file size in each mode, divide that by 10, that's how much data is recorded on the card each second.

ectobuilder
06-09-2011, 10:47 AM
You can test this, record for 10 seconds in both modes. Check the file size in each mode, divide that by 10, that's how much data is recorded on the card each second.

Ah basic proof test.

Tony Hernandez
06-09-2011, 02:56 PM
like this. normal 24p FX is 24Mbps. when you overcrank in S&Q mode, it maintains the 24Mbps, based on 24p. So if you overcrank to 30fps, it records at 30Mbps. 60fps is 60Mbps. That way when the footage is slowed down to 24p, you still have a 24Mbps stream.

So recording 28Mbps 1080/60p is NOT the same as recording 24Mbps 24p, and overcranking to 60. Overcranking is much better quality than native.

Think of it like this. This is not how the data is spread out under normal shooting, but if every frame was equal then....

24P 24Mbps = 1Mb per frame.
60P 28Mbps = .47Mb per frame.

this is why you may use a class 4 SD card for normal shooting, but S&Q requires a class 10 card. It's in the manual.


AVCHD is max at 24mbps, sony implements up to 28mbps for 60p.
This means 28 divided by 60 frames, this means that to have the same quality as for 24P it need to be rated at 60mbps and not 28mbps like sony mentions on its specs, this means -over my tech. point of view- that recoding at 60P have 0.466Mb per frame like you write.

So and as notice:
24P 24Mbps = 1Mb per frame.
60P 28Mbps = 0.47Mb per frame.

So at 60P the quality per frame is inferior.

I hope to be wrong, i wish, but maths

harrisoncj
06-09-2011, 03:45 PM
It shoots 1080 60p on my class 6 Sandisk. I didn't think it would but I tried it out today.

cheezweezl
06-09-2011, 04:09 PM
I hope to be wrong, i wish, but maths

congrats, you get your wish. AVCHD may max out at 28Mbps but that would be in it's playback format. The FS100 records 60fps S&Q at 60Mbps with the intention of a file that plays back at 24Mbps. That's why you need class 10 cards to do it.

I just did the test so I could reassure myself and others. I recorded 10 seconds (roughly, by my iphone's stopwatch) of 1080p/60 28Mbps, and then 1080p/24 24Mbps overcranked to 60 frames.

the two files which contain the same number of frames (+/- 10% for human error), are completely different when it comes to file size. the 1080p/60 file is 35.9MB. The 1080p24 file is 76MB.

So, lets translate that file size to bit rate. 76MB x 8 = 608Mb. Then, 608Mb 10sec = 60.8Mbps. Now I can't claim to have recorded exactly 10 seconds, But I can say with confidence that I was off by less than one second. So this all adds up to 60frame overcrank at 24p FX records at 60Mbps.

And just in case you were wondering. If I do the same math on the 1080p/60 file, it comes out to 28.72Mbps. Exactly what it should be.



It shoots 1080 60p on my class 6 Sandisk. I didn't think it would but I tried it out today.

1080/60P or 1080/24P overcranked to 60? If it's 24p, then that is good news for all of us. class 6 cards are dirt cheap!!! If it was 1080/60P, you can actually do that with a class 4 card, according to sony...

harrisoncj
06-09-2011, 04:43 PM
24p overcranked to 60.

cheezweezl
06-09-2011, 04:50 PM
24p overcranked to 60.

that's great news. that may have just doubled my SD card supply. I have some class 6 just laying around. THANKS!!!

David G. Smith
06-09-2011, 05:00 PM
Oh man, these threads give me a headache! I mean, shoot.... I gotta use all my fingers, all my toes and drop my trousers just to count up to 23!!!! (.... Think about it.... Think about it!!!). :grin:

Tony Hernandez
06-09-2011, 05:05 PM
congrats, you get your wish. AVCHD may max out at 28Mbps but that would be in it's playback format. The FS100 records 60fps S&Q at 60Mbps with the intention of a file that plays back at 24Mbps. That's why you need class 10 cards to do it.

I just did the test so I could reassure myself and others. I recorded 10 seconds (roughly, by my iphone's stopwatch) of 1080p/60 28Mbps, and then 1080p/24 24Mbps overcranked to 60 frames.

the two files which contain the same number of frames (+/- 10% for human error), are completely different when it comes to file size. the 1080p/60 file is 35.9MB. The 1080p24 file is 76MB.

So, lets translate that file size to bit rate. 76MB x 8 = 608Mb. Then, 608Mb 10sec = 60.8Mbps. Now I can't claim to have recorded exactly 10 seconds, But I can say with confidence that I was off by less than one second. So this all adds up to 60frame overcrank at 24p FX records at 60Mbps.

And just in case you were wondering. If I do the same math on the 1080p/60 file, it comes out to 28.72Mbps. Exactly what it should be.




1080/60P or 1080/24P overcranked to 60? If it's 24p, then that is good news for all of us. class 6 cards are dirt cheap!!! If it was 1080/60P, you can actually do that with a class 4 card, according to sony...


Like you said .. "the 1080p/60 file is 35.9MB"
the 60P file is 287mb/10 seconds = 28mbps
So 28 mbps for a file that have 60 frames on a full second, well ?
That means each frame on 1080p60 -if a second have 60 frames- is 0.46megabit per frame
so:
1080p60 equal -0.5mb per frame
1080p24 equal +-1mb per frame

Or is there're some i missing ?

cheezweezl
06-09-2011, 05:24 PM
Like you said .. "the 1080p/60 file is 35.9MB"
the 60P file is 287mb/10 seconds = 28mbps
So 28 mbps for a file that have 60 frames on a full second, well ?
That means each frame on 1080p60 -if a second have 60 frames- is 0.46megabit per frame
so:
1080p60 equal -0.5mb per frame
1080p24 equal +-1mb per frame

Or is there're some i missing ?


no you got it right. if you shoot 1080p/60, it's only 28Mbps or .46666Mb per frame. 1080p/24 is 24Mbps or 1Mb per frame.

The important point is that if you record 60fps using the S&Q option while set to 24p, it records at 60Mpbs so that when you play back the slow motion, your 24Mbps data rate is maintained.

In other words, when you are recording 24p and you overcrank to 60 frames, there is ZERO loss in quality.

Tony Hernandez
06-09-2011, 06:17 PM
So why you tell me some time ago that im not true.
I was said that recording at 60P (1080p60) on FS100, have less quality than recording at 1080p24, and your file your comments and the ones by me then confirms that.

I dont like to have to use the Overcranking feature instead of default rec. for the 60P to have not less quality.

And another thing that i suspect is related to the overcranking feature.
Yet as for to know if that using the S&Q will be really mantain the quality, tell me:
Does the clips recorded at S&Q feature for slow motion (60P) from 24P mode, have 60 frames per second ? or only have really 24 frames in each second ?

Cause i think that starting from a 24p rec. mode, starts a 24fps rec. mode, and even doing slow motion, the frames maybe 24p on file, can you reply the above question ..
Your reply may allow to determine if as for mantain the quality in 60p, then the camera need to start from 24p then do slow motion feature, or anyway the quality wil be less for 60p.

cheezweezl
06-09-2011, 07:23 PM
So why you tell me some time ago that im not true.
I was said that recording at 60P (1080p60) on FS100, have less quality than recording at 1080p24, and your file your comments and the ones by me then confirms that.

I dont like to have to use the Overcranking feature instead of default rec. for the 60P to have not less quality.

And another thing that i suspect is related to the overcranking feature.
Yet as for to know if that using the S&Q will be really mantain the quality, tell me:
Does the clips recorded at S&Q feature for slow motion (60P) from 24P mode, have 60 frames per second ? or only have really 24 frames in each second ?

Cause i think that starting from a 24p rec. mode, starts a 24fps rec. mode, and even doing slow motion, the frames maybe 24p on file, can you reply the above question ..
Your reply may allow to determine if as for mantain the quality in 60p, then the camera need to start from 24p then do slow motion feature, or anyway the quality wil be less for 60p.

1. i'm not the one who said you were wrong.

2. we are talking about overcranking maintaining 24Mbps quality. we were never talking about quality of native 60p vs. native 24p. it's obvious that native 60p is less quality and not worth debating.

3. my comments and calculations were for anyone saying that when overcranking, the quality would not be as good.

4. i'm not quite sure what your goal is or even what you are asking me, but maybe this will help. overcranking is NOT the same as recording at 60p native. no sound and you end up with a 24fps, slow motion clip. however, it is recorded at a much higher bit rate than 60p native so if sound isn't important to you, you could always take that 24p slow motion clip and conform it to 60p using cinema tools or something. then you would have true 60p, at the best quality but with no sound.

5. my head hurts.

dustylense
06-09-2011, 10:09 PM
LOL! Guys, megaBITS and megaBYTEs are two very different things. You could shoot AVCHD on class 4 cards. Cheez, 60Mbs is is 7.5 megaBYTES/sec. Where those class 10 cards come in handy for AVCHD is transferring your footage.
Here is a calculator for you all to use: http://www.translatorscafe.com/cafe/units-converter/data-storage/calculator/megabit-to-megabyte/

jetswing
06-09-2011, 10:25 PM
LOL! Guys, megaBITS and megaBYTEs are two very different things. You could shoot AVCHD on class 4 cards. Cheez, 60Mbs is is 7.5 megaBYTES/sec. Where those class 10 cards come in handy for AVCHD is transferring your footage.
Here is a calculator for you all to use: http://www.translatorscafe.com/cafe/units-converter/data-storage/calculator/megabit-to-megabyte/

Class 4 cards have speed of 4MB/s which is good for regular HD recording. But for S&Q Motion recording class 10 is recommended. Some of the class 6 cards might be fast enough to handle S&Q. If you've spent $5k on a camera, you can afford couple of class 10 cards.

cheezweezl
06-09-2011, 10:56 PM
LOL! Guys, megaBITS and megaBYTEs are two very different things. You could shoot AVCHD on class 4 cards. Cheez, 60Mbs is is 7.5 megaBYTES/sec.

Yup. I know the diff between a bit and a byte. 8 bits in a byte. All my math on this thread reflects that.

With that said, I can reliably record 48fps overcrank on my ex1 on a class 6 card. That comes in at 8.75MB/s. So based on this, I could probably get away with using my old class 6 cards on the fs100 in S&Q. However, my class 6 cards are fast. Faster than some other cards badged as class 6. So I can see why Sony says to go for class 10 cards. That way, even the slower of the bunch can still pull it off.

Either way a new class 10 16GB card is $26. If you're too broke to swing that, you probably shouldn't be buying a camera. Maybe think about getting some lunch first. lol...

ectobuilder
06-10-2011, 12:33 AM
AVCHD is max at 24mbps, sony implements up to 28mbps for 60p.
This means 28 divided by 60 frames, this means that to have the same quality as for 24P it need to be rated at 60mbps and not 28mbps like sony mentions on its specs, this means -over my tech. point of view- that recoding at 60P have 0.466Mb per frame like you write.

So and as notice:
24P 24Mbps = 1Mb per frame.
60P 28Mbps = 0.47Mb per frame.

So at 60P the quality per frame is inferior.

I hope to be wrong, i wish, but maths

Remember that perceived image quality has to do with 1) Spatial Resolution (pixels/color) and 2) Temporal Resolution (respect to time; frame rate).

Therefore in theory 60p should give a higher perceived quality due to it's inherent higher Temporal Resolution over 24p.

However as you pointed out, each frame should get HALF the dedicated throughput of data when recording in 60p than in 24p (with the FS100 implementation of AVCHD).

HOWEVER, keep in mind that this might be offset by the fact that we have increased Temporal Resolution by 2.5 times over 24p.

Also the compression level of AVCHD may reach a plateau where the human eye can no longer easily perceive the difference in image quality due to compression. This may be supported by the fact that 24Mbps AVCHD off of the FS100 have been compared to footage recorded to ProRes422 HQ @ 220Mbps and the perceptive difference is negligible to the naked eye.

cheezweezl
06-10-2011, 01:39 AM
...and the perceptive difference is negligible to the naked eye.

sure, until you start grading it and it falls apart....

ectobuilder
06-10-2011, 03:03 AM
sure, until you start grading it and it falls apart....

Yes yes of course.

MazingerZ
06-10-2011, 03:59 AM
sure, until you start grading it and it falls apart....

I haven't seen any 1080p60 28Mbps material fall apart yet.
And I mean a properly exposed video with normal grading.
And viewing it at normal 60fps, not slowed down or viewing it frame by frame.

cheezweezl
06-10-2011, 11:44 AM
To be fair, Ive been to busy to throw any of this footage on the resolve as of yet. So i cant speak to the 28mbps with any real world experience. But you can grade pretty much any footage that has been properly exposed. It's those shots that have serious problems or shots that are underexposed to preserve highlights that will separate the men from the boys, codec-wise.