is the AF100's 24 mbps enough to handle fast motion/complex scenes???

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Nicholas Natteau

Veteran
As a current hacked GH1/GH13 owner who shoots 42 Mbps in AVCHD mode, I'd like to know if 24 mbps is enough to handle such complex scenes as water flowing, fast motion, trees blowing in the wind.

It seems like 24 mbps is not that much more than 17mbps, but is it enough of a difference to handle any scene?

The reason I'm asking is that I'm seriously considering buying the AF100. The only thing holding me back is my uncertainty about AVCHD performance at 24mpbs. At a maximum bitrate of 24mbps, can the AF100 handle a scene with a lot of movement or fast motion?

Thanks in advance for any advice / feedback.
 
Bit rate is not everything. The consumer-level codec in the GH1(3) is NOT the same as the AVCCAM codec of the AF-100. When I was shooting with the HMC-40, which uses the same (or very, very similar) codec as the AF-100, I never had a problem with high-detail scenes. And I'm not expecting to have a problem with the AF-100.
 
Stephen... I concur as I have the HMC150. The GH1 is not the same codec and frankly not the same league. You have a lot of rants against AVCHD and I for one have loved it. I've never missed DVCPRO HD at all, and certainly not P2 cards. It's just that the fan boys have gone crazy after the hack, yet fail to realize that it's not a proper videocamera and although it might do the job, it's a PITA to use. Just like the 7D is a PITA... For me, back in the day I used P2 but even that was a PITA due to data size and lenght of run time. I think with a complex world, it's about having a decent and more enjoyable process... That's the evolution of having a real videocamera and not a hacked something or other... I for one also don't think that having a recorder will get you much more out of the image, other than redundancy on the media. That'll save me 2k to put into glass.
 
Justyn said:
I for one also don't think that having a recorder will get you much more out of the image, other than redundancy on the media. That'll save me 2k to put into glass.
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I am also very interested to see this... I know it has been stated that side by side the native footage vs shots pulled off of the recorder (can't remember which one) were "practically identical", but that was with the pre-pro models. It will be interesting to see the final verdict with a few more stringent tests witht he final production models.
 
Nicholas Natteau said:
It seems like 24 mbps is not that much more than 17mbps, but is it enough of a difference to handle any scene?
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Those megabits aren't the same. The AVCCAM megabits are worth a lot more than the GH1 megabits! It's like having 24 Pounds Sterling, vs. 17 pesos. Sure, the number may not sound that different, but the value is hugely different.

24mbps on the AF100 is probably equivalent to somewhere around 50 or 60mbps on a GH13. Wild guess, but I don't think I'm wrong.

The only thing holding me back is my uncertainty about AVCHD performance at 24mpbs. At a maximum bitrate of 24mbps, can the AF100 handle a scene with a lot of movement or fast motion?
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Of course it can. It can handle most anything that gets thrown at it. I have seen a tiny bit of crunchiness show up in an extreme case of ... well, basically a codec torture test, lots of waterfalls, gobs of ripples across the surface of the water, billions of blades of fine grass and lots of trees with tiny leaves blowing around. In that specific case, I could see a little bit of sharp edges here and there. If you paused it and pixel-peeped it, yes you could see some ... I wouldn't call it "macroblocking" because it wasn't anything like HDV, but ... maybe "microblocking" is the right word. Anyway -- something that 99% of people would never notice while it was in motion.

Here's the other thing -- if you shoot variable frame rates, the camera actually increases the bitrate. Not at liberty to detail my exact findings yet, but let's put it this way -- you need a Class 6 card, as a Class 4 card can't even handle the bitstream the AF100 throws at it.

I think probably 95% of the folks out there won't need or even bother with an external recorder. I think that those who do extensive VFX might get a Nano for effects shots or chroma keying (although I bet it will key adequately in the native codec; people have pulled good keys from EX1 footage).
 
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Justyn said:
I for one also don't think that having a recorder will get you much more out of the image, other than redundancy on the media.
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The major benefits to going with an external recorder will be:
1) It does provide redundancy of media, which some people will definitely be attracted to. If I was shooting for a client and handing the footage off, like in the tape days, I'd like to have my own copy too, so redundancy is good.
2) It provides for 4:2:2 color for those who need it for VFX or extensive chromakeying work.
3) It makes the edit process a little easier for Apple editors, because the recorders can record in direct Quicktime format.

Whether any of those reasons is justification for you to spend the $2k-$3k for a recorder, well, that's a personal decision. I think that folks should definitely try out the native codec before springing for an external recorder. I think most people will find that the native codec is plenty adequate for most purposes.
 
jmmusic said:
Hi, Barry. Do you have any actual tests that show this?
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I have a lot of experience playing with the GH13, and I know AVCCAM pretty well. I am giving seat-of-the-pants impressions, not direct test results. I will absolutely assert that the AF100 at 24mbps is embarrassingly superior to the GH1 at 24mbps, and it is my opinion that you would have to push a GH13 to at least 50mbps before it would be competitive with the AF100 at 24.

I don't have a direct way to compare codecs directly but am actually working on trying to do exactly that.
 
Thanks everybody for replying and thanks Barry in particular for that detailed explanation. I had no idea that the AF100's 24Mbps codec was actually much closer to the GH13's 50 to 60 Mbps performance. If that's the case, then I'm definitely getting the AF100. Thanks for clarifying the 24 mbps vs 17 mbps issue.
 
I'm really happy with the 24mbps that the hmc151 offers, never had anything weird happen, no macro blocking, just nice pictures. I guess the 24mbps in the AF-100 are as good or better (natural evolution of engineering).
 
I forgot to ask, does the AF100 also record in 24 Mbps at 720p60 or only at 1080p?

If the mbps is 17mbps at 720p60, is that still enough to handle all kinds of motion or complex scenes if one chooses to shoot at 720p60???
 
Nicholas Natteau said:
I forgot to ask, does the AF100 also record in 24 Mbps at 720p60 or only at 1080p?

If the mbps is 17mbps at 720p60, is that still enough to handle all kinds of motion or complex scenes if one chooses to shoot at 720p60???
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If it works as the hmc both modes use 24mbps.
 
Nicholas Natteau said:
I forgot to ask, does the AF100 also record in 24 Mbps at 720p60 or only at 1080p?

If the mbps is 17mbps at 720p60, is that still enough to handle all kinds of motion or complex scenes if one chooses to shoot at 720p60???
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PH mode is the top-quality mode and it's available at full bitrate in 1080p, 1080i, and 720p.

There are lower-bitrate modes available too; there's a 17mbps mode and a 6mbps mode, but those are only available in 1080i.
 
Fantastic, thank you. I've gone ahead and ordered my AF100. B&H says it's "back-ordered". I guess it'll be at least two months before I receive it.
 
I think many underestimate the value of uncompressed quality acquisition. If that actually does get down to the $1K level (Ninja), then IMO it's just as important as nearly anything you can add on to the AF100.

I have no doubts that the AVCCAM will probably look perfectly fine in almost all situations...at first blush. It's when you have to do some heavy lifting in post where it may not be so great.

What happens if you need to lift the (potentially noisy) shadows in an underexposed shot that happens to also have alot of detail and motion in the frame? If it's AVC, it may look *ok* after alot of fiddling, but in all likelihood it won't be possible to push the image even close to as far as a (nearly) uncompressed 4:2:2 image. (Ninja, KiPro, NF)

What the outboard recorder enables is the ability to deliver on Blu-ray the same, or better quality as PH mode, instead of something much more degraded due to heavy compression in the original files.
 
I agree that using an external recorder will benefit most when shooting under exposed footage that will need to be corrected in post.



Elton said:
I think many underestimate the value of uncompressed quality acquisition. If that actually does get down to the $1K level (Ninja), then IMO it's just as important as nearly anything you can add on to the AF100.

I have no doubts that the AVCCAM will probably look perfectly fine in almost all situations...at first blush. It's when you have to do some heavy lifting in post where it may not be so great.

What happens if you need to lift the (potentially noisy) shadows in an underexposed shot that happens to also have alot of detail and motion in the frame? If it's AVC, it may look *ok* after alot of fiddling, but in all likelihood it won't be possible to push the image even close to as far as a (nearly) uncompressed 4:2:2 image. (Ninja, KiPro, NF)

What the outboard recorder enables is the ability to deliver on Blu-ray the same, or better quality as PH mode, instead of something much more degraded due to heavy compression in the original files.
Click to expand...
 
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