Panasonic AF100 HD-SDI?

Kindredmachine

Kindredmachine

Well-known member
We're looking into new cams and the announced AF100 really caught my eye. A 4/3" CMOS sensor seems like it could be pure liquid sweetness, but I noticed that it's an AVCHD cam. Last I heard AVCHD uses Mpeg4 (h.264) at 24mb/s? Wouldn;t this create an overcompressed image that would look terrible? Allof our projects are for Bluray release and I would think the difference between mpeg4 compression (even a good one) and mpeg2 is night and day?

I did notice however, that it has HD-SDI output. From someone with more experience with SDI, do you suppose this means we could record full 4:2:2 color Mpeg-2 50mb/100m/s onto an external source, say onto a Nanoflash? I've never used SDI so I'm not sure if that would be a universal options for all cams that carrie this or if still have to "wait and see" when we get closer to release?

http://www.bhphotovideo.com/c/produ...AG_AF100_Micro_4_3_Professional.html#features
 
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Kindredmachine said:
But I noticed that it's a AVCHD cam... say wha? Isn't that like buying a Ferrari and swapping out the engine for a 4 cilinder? Last I heard AVCHD uses Mpeg4 at like 24mb/s? BLAH, whats the point?
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What's the problem? It's a codec that performs better than that offered by a major competitor on a $20,000 2/3" camcorder, so ... hey, it isn't perfect, but it certainly isn't bad.

I did notice however, that it has HD-SDI output. From someone with more experience with SDI, do you suppose this means we could record a full 100mbs image (before it's compresses to a terrible 24mb/s image) onto an external source, say onto a Nanoflash?
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Well, if you want to compress it to a "terrible" 24mb/s image, you'd have to record onto the NanoFlash in HDV mode. :D

The onboard AVCHD recording will BEAT THE LIVING HELL out of HDV, and I think you're really selling it short. It's really surprisingly good, considering the bitrate. It's better than 35mb/s MPEG-2, and probably about equivalent to 45mb/s MPEG-2.

But -- regardless -- if you want to use the Nano, of course you can. It'll output a full HD uncompressed signal, which you can record on the Nanoflash at 280mbps Intraframe, if that's what you want. No problem.


However, you won't be recording a 10-bit image, because the Nano only records 8-bit.
I've never used SDI so I'm not sure if that would be a universal options for all cams that carrie this or if still have to "wait and see" when we get closer to release?
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Nothing to wait and see about -- SDI is a standardized output, so yes it'll work.

I'm strongly considering a Nano as well, to pair with it. I think AVCHD is a fine codec, but the notion of 280mbps intraframe is really appealing.
 
AVCHD uses a h.264 codec which is I'm pretty sure is Mpeg4 right? If Mpeg-4 compression at 24MB/S can really create the quality, grain and color in this cam of 45mb/s MPEG-2 then that would be fantastic but honestly I have a hard time believing it. But thank you very much for the information regarding the Nanoflash. If we can indeed use the SDI output to bypass the Mpeg-4 24mb/s compression and capture a true 4:2:2 Mpeg-2 50mb/100mb/s then this camera could potentially blow away anything else on the market for under $10k.
 
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Kindredmachine said:
AVCHD uses a h.264 codec which is I'm pretty sure is Mpeg4 right?
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AVC, aka h.264 is, indeed, a flavor of MPEG 4. There are many flavors of MPEG4. BTW, Blu-Ray can also be encoded with h.264.

At the same bit rate, video that has a lot of motion or texture that's encoded with h.264 can look much better than it can with MPEG 2.
 
Barry_Green said:
However, you won't be recording a 10-bit image, because the Nano only records 8-bit.

Nothing to wait and see about -- SDI is a standardized output, so yes it'll work.

I'm strongly considering a Nano as well, to pair with it. I think AVCHD is a fine codec, but the notion of 280mbps intraframe is really appealing.
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Personally, I'd look at a Ki Pro from AJA or a Cinedeck. The Ki Pro costs a little more and is bigger, but it offers full 10 bit recording to Apple's Pro Res codec. The Cinedeck is quite a bit more, but it can record in 10 bit or 12 bit to Cineform's codec.
 
Thanks for the info... Since we're going from SD productions into HD productions this year, my perception of h.264 is changing. I just assumed we would use Mpeg-2 compression for our upcoming Bluray projects but now I don;t think that'll be the case. It seems most studios are now using the AVC (h.264). I feel like I'm behind the times. The last 3 years has moved fast.
 
Kindredmachine said:
Or maybe my perception of 24mb/s compression is skewed. My expereince has been with the HDV format.
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Yeah, I can see where you're coming from, but HDV is MPEG-2, not MPEG-4. Think about it this way: Sony themselves say that if you want to get equivalent picture quality to 25mb/sec HDV, you could do it with 9 megabits of h.264. Nine. 21mb/sec of properly-implemented h.264 is vastly superior to HDV.
 
Kindredmachine said:
I just assumed we would use Mpeg-2 compression for our upcoming Bluray projects but now I don;t think that'll be the case. It seems most studios are now using the AVC (h.264). I feel like I'm behind the times. The last 3 years has moved fast.
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Yes indeed, I think you'll want to reconsider that notion. While Blu-Ray does support both MPEG-2 and h.264, h.264 is just a vastly superior codec. The often-quoted comparison is that h.264 delivers equivalent quality to MPEG-2 at less than half the bitrate, or, put another way, h.264 is two to two and a half times more efficient. Which is why I said AVCHD should be easily a match for 45 megabits/sec of MPEG-2.
 
Yep, you're right. I've been reading up on h.264 and that seem to be the way to go, especially at higher bitrates. But I'm still teetering betwween an EX1R wit Nanoflash to get the 100mb/s bitrate with 4:2:2 color VS the upcoming AF100. I read that the AF100 even with a nanoflash will still push out 4:2:0 color. What do you guys think? Would you prefer the 4/3" chips even at 4:2:0 color over the EX1R with 1/2" chips and 4:2:2 color... both using nanos of course capturing at 100Mb/s. It's a tough call for me since both rigs will sitting at around $10k.
 
Kindredmachine said:
I read that the AF100 even with a nanoflash will still push out 4:2:0 color.
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Nonsense.

Would you prefer the 4/3" chips even at 4:2:0 color over the EX1R with 1/2" chips and 4:2:2 color... both using nanos of course capturing at 100Mb/s.
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That's a question nobody will have to answer, because the HD-SDI and HDMI on the AF100 are going to certainly be 4:2:2.

The only question is whether the AF100 would be 8-bit or 10-bit, and again, for a nano user, that would be irrelevant because the nanoflash records 8-bit.

As for a true comparison between those two, we'd have to see them both to be sure. But in regards to your question: I think you'll find that almost everyone would prefer the bigger chip... people are using DSLRs just for the bigger chip, even with all the compromises that it involves. People will put up with no decent audio inputs, no manual controls, heck - not even 24fps, they'd conform the 5D's 30p to 24fps, they'd put up with no exposure tools (no zebras, no waveform, no vectorscope, no "marker"), they'll put up with having to record double-system sound and then sync up their sound in post, they'll put up with no ability to zoom whatsoever, they'll put up with not even being able to monitor while recording (on the GH1), they'll put up with not being able to shoot wide-angle deep-focus shots because of the moire and aliasing, they'll open up their wallets to buy rigs to cover up the idea that you can't shoot handheld... they'd do almost *anything* to get that huge sensor.

With the AF100, you shouldn't have to sacrifice any of that. The AF100 should be (I said "should" be) the ideal marriage between an EX1 (well, EX3 actually) and DSLR. All the good of both, with none of the drawbacks of either.

If the promise holds, and the images are as sharp and detailed on the AF100 as they are on the EX1, then your choice is: do you want shallow DOF and interchangeable lenses, or not?

But we won't know the real answers until we get to use a working model.
 
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I was suprised to hear that as well but here the article that states Panasonic said "live raw output will be 4:2:0 color"... DVX doesn't allow me to post the full URL without blocking it, but it's... http://eoshd (dot com) /content.php?157-Panasonic-AF100-features-RAW
 
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Awesome post. I'm with you, but tired of strumming my fingers waiting for the 'convergence' to gel.

Barry_Green said:
Nonsense.


That's a question nobody will have to answer, because the HD-SDI and HDMI on the AF100 are going to certainly be 4:2:2.

The only question is whether the AF100 would be 8-bit or 10-bit, and again, for a nano user, that would be irrelevant because the nanoflash records 8-bit.

As for a true comparison between those two, we'd have to see them both to be sure. But in regards to your question: I think you'll find that almost everyone would prefer the bigger chip... people are using DSLRs just for the bigger chip, even with all the compromises that it involves. People will put up with no decent audio inputs, no manual controls, heck - not even 24fps, they'd conform the 5D's 30p to 24fps, they'd put up with no exposure tools (no zebras, no waveform, no vectorscope, no "marker"), they'll put up with having to record double-system sound and then sync up their sound in post, they'll put up with no ability to zoom whatsoever, they'll put up with not even being able to monitor while recording (on the GH1), they'll put up with not being able to shoot wide-angle deep-focus shots because of the moire and aliasing, they'll open up their wallets to buy rigs to cover up the idea that you can't shoot handheld... they'd do almost *anything* to get that huge sensor.

With the AF100, you shouldn't have to sacrifice any of that. The AF100 should be (I said "should" be) the ideal marriage between an EX1 (well, EX3 actually) and DSLR. All the good of both, with none of the drawbacks of either.

If the promise holds, and the images are as sharp and detailed on the AF100 as they are on the EX1, then your choice is: do you want shallow DOF and interchangeable lenses, or not?

But we won't know the real answers until we get to use a working model.
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Kindredmachine said:
I was suprised to hear that as well but here the article that states Panasonic said "live raw output will be 4:2:0 color"... DVX doesn't allow me to post the full URL without blocking it, but it's... http://eoshd (dot com) /content.php?157-Panasonic-AF100-features-RAW
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Get your news from accurate sources. There is not a single doubt in my mind whatsoever that it will be full 4:2:2 output.
 
Well that's music to my ears, I appreciate all of your input and it looks like I'm just going to hold off until the AF100 comes out. :thumbsup:
 
mcgeedigital said:
Any news on wether the output will be 8 or 10 bit, sir?
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No news of any such type, but I do hope to know more soon.

I won't be surprised if the output is 8-bit; all the AG-series are 8-bit, all the AJ's are 10-bit (except the HPX300/370, which is an AG but was built by the AJ factory, so it's a bit of a crossover).

I'm hoping for 10, but won't be surprised if it's 8-bit within a 10-bit wrapper.
 
hd-sdi would be somewhat pointless in a 4:2:0 color space. I can't imagine they would build this camera with all it's wonderful specs and only have 4:2:0 color space. But then again, I have seen weirder things happen.
 
Barry_Green, since I have your attention (which I greatly appreciate) I'm eyeing a SmallHD DP6 field monitor and they have a version with SDI and one without. I'm curious if one could output HDMI video to your field monitor AND output SDI video to your nanoflash simultaniously? Or when it comes to the signal going out, is it only one or the other at one time?

If that's the case, theirs a DP6 monitor with 2 SDI "ports" (for passthrough)... I'm assuming I could then run a SDI signal into the monitor and then out to a nanoflash (or vice versa) at the same time right?
 
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