Footage on SxS cards at 60fps?

[Michael B. McGee]

I just caught wind of the E-films MxR 3-for-2 sale. sounds tempting and i think i'm ready to make the economical switch. so, with that said i'm thinking about selling my SxS cards. i'd like to keep one for over-cranking at 60fps (HQ that is, if it makes a difference from SP). i'm curious to know how much footage i can get from a 8gb or 16gb card at 24P and/or 30P playback? i'm horrible at converting and plus isn't the data rate different when shooting S&Q?


thanks in advance.

-Mike

[Vincent Oliver]

You won't get any "footage" on a 8 or 16gb memory card. However using a 16gb card you will get

57 min @ 720 - 25 or 50p
57 min @ 1080 HQ
79 min @ 1080 SP

[Michael B. McGee]

are you sure? that doesn't seem right. those are the same times as 24P shooting. if you are right then all logic (at least mine) goes out the window.

[Vincent Oliver]

Just checked again, this time setting the camera up for NTSC (24P is not an option for PAL)

57 min @ HQ 1080/60i
79 min @ SP 1080/60i
57 min @ HQ 1080/30P
57 min @ HQ 1080/24P
79 min @ SP 1080/24P
57 min @ HQ 720/60P
57 min @ HQ 720/30P
57 min @ HQ 720/24P

I guess with an 8gb card you should half the record times. I do not use cards less than 16 gb

TIP of the DAY

SDHC cards will not allow you to record using overcranking. However if you keep an SxS card in one of the slots and use that to capture the overcranking scene, you can then transfer that clip, in camera, to a SDHC card without losing the overcranking feature.

[Alister Chapman]

Those storage times are based on Playback times. When shooting S&Q the data rate for playback is 35Mb/s so shooting at 60fps records at 70Mb/s, playing back at 35Mb/s. So if you shoot using S&Q at 60fps you will only be able to shoot for about 27mins on a 16Gb card.

720P60 (non S&Q) records and playsback at 35Mb/s.

[Adam Stanislav]

Originally Posted by Michael B. McGee

if you are right then all logic (at least mine) goes out the window.

No, it does not. 35 mbs at 24p gives you the same number of bits to store on the same size disk as 35 mbs at 60i does. It is not the number of frames per second that matters, it is the number of bits per second. So you should fit the same number of minutes in a given disk space whether you shoot 24p, 30p, or 60i.

[Vincent Oliver]

Originally Posted by Michael B. McGee

i'm curious to know how much footage i can get from a 8gb or 16gb card at 24P and/or 30P playback?
-Mike

This was the question. I have not checked the recording times for S&Q but I am sure you are right Alister. The battery has run out in my calculator and come to think of it also in my brain. :-)

[Michael B. McGee]

Originally Posted by Alister Chapman

Those storage times are based on Playback times. When shooting S&Q the data rate for playback is 35Mb/s so shooting at 60fps records at 70Mb/s, playing back at 35Mb/s. So if you shoot using S&Q at 60fps you will only be able to shoot for about 27mins on a 16Gb card.

720P60 (non S&Q) records and playsback at 35Mb/s.

Thanks Alister. those numbers sound better. anybody want to buy a couple of 8gb SxS cards?

[Nathan Hudson]

Another wrench to throw in there is that the codec uses a Variable Bit Rate.

[Vincent Oliver]

Originally Posted by Michael B. McGee

Thanks Alister. those numbers sound better. anybody want to buy a couple of 8gb SxS cards?

You can't overcrank to 60 fps with a SDHC card, so I am not sure what your question was all about.

If you want to overcrank then keep your 8 gb cards.

[Michael B. McGee]

i said, "i'd like to keep one". which will be a 16gb SxS.

[Vincent Oliver]

A quick and easy answer to your original question would be to put empty 8 gb and 16 gb cards in slots A and B and then select the various recording options, the recording time is displayed in the top left hand corner.

My final word on this.

[Michael B. McGee]

Originally Posted by Vincent Oliver

A quick and easy answer to your original question would be to put empty 8 gb and 16 gb cards in slots A and B and then select the various recording options, the recording time is displayed in the top left hand corner.

My final word on this.

that might be your final word, but i think you're still incorrect. just like Alister mentioned, those are/"should be" playback times not record lengths. i just performed a test since i started the topic and here's what i discovered:

format: HQ 720/24P recording S&Q at 60fps
media: 8gb SxS card with 28 minutes displayed on LCD.

i pressed record on the camera and started my stopwatch simultaneously. i wanted to see what the "real time" record length would be.

results:
clip length was 31:46 minutes
real time was 12:42 which is 2.5 times slower than clip/playback length. (60 vs 24)

first of all i found it interesting that i was able to get a clip of 31:46 and not approximately 28 minutes like the LCD displays. now i was recording black with the lens hood shutters closed. so, there was absolutely no detail whatsoever.

so what does this mean? does the real time record length reflect with the frame rate as my results suggest like with film or is Alister correct in that the camera records at 70Mb/s at 60fps?

i have 2 more questions:

1. at what point does/should the camera record at 70Mb/s in S&Q Motion, ie: 30/45/60fps?

2. if these EX cameras normally(24/25/30P) record at 35Mb/s does that mean at 24P i'll have more detail/info in each frame than shooting at 25/30P? or does the VBR balance all of that out?

[Vincent Oliver]

I give you full credit for perservering with this topic Michael.

From my work I just shoot until a card indicates it is full and then I continue on another card. I think you have answered your own question with your experiment. Maybe if you shot some autumn leaves using the same card you might only get 26 minutes of record time, in the same way that a JPEG of a clear blue sky will be a smaller file than a JPEG of a woodland scene.

[Michael B. McGee]

Originally Posted by Vincent Oliver

I give you full credit for perservering with this topic Michael.

From my work I just shoot until a card indicates it is full and then I continue on another card. I think you have answered your own question with your experiment. Maybe if you shot some autumn leaves using the same card you might only get 26 minutes of record time, in the same way that a JPEG of a clear blue sky will be a smaller file than a JPEG of a woodland scene.

yeah, i know i'm getting really technical here, but i just like to know how things work. i'm really curious about this 70Mb/s bitrate at 60 fps. i can't seem to find any literature from Sony verifying this statement.