Cineframe 24 on FX1 unusable !

[Joel Corral]

i shot some footage on my HDR-FX1 using the preset for CF24. why would anyone want this footage? to me it looks rather choppy nothing like film.

can someone shed some light for me? what am i missing here?

[Chris Hurd]

Like any other frame rate, CF24 is an aesthetic -- a stylistic choice. Some folks will like the way it looks and some won't.

[Barry Green]

I think the only thing you're missing is Sony's marketing leads people to think that CineFrame 24 would be a film simulation. It clearly isn't a very good one.

As Chris said, the CF24 can be thought of as a digital effect. If you like it, use it, if you don't, don't. But it's not really filmlike at all, that is true.

[Joel Corral]

well i also have a GL2 and when i shoot in frame mode @ 30fps its rather nice. i like it, but this CF24 is really not even close. i was hoping for a non interlaced look with that CF24 but oh well.

[Barry Green]

I'm totally in agreement, CF24 might work for a talking-head interview shot, but nothing else -- the motion rendition is very erratic.

CF30 should give you a similar effect to frame mode on the GL2 though.

[Heath McKnight]

My student wants to use the CF24 for his film on Sunday. I'm thinking he should nix the idea and just use some software to go to 24p.

Thoughts?

heath

[Barry Green]

I've seen enough CF24 to say that nobody should ever use it who's trying to get a filmlike feel. It just doesn't work.

For software 24P conversion, what software are you thinking of -- is there one out yet? DVFilm's working on theirs but it's not out yet. I guess the full version of MB should be able to do it. Thing is, if you don't have existing software you may not be able to do it.

CF30 looks pretty good, and it gives a sort-of-filmlike feel, so CF30 may be an option to consider.

[Heath McKnight]

Thanks, Barry!

heath

[Graeme Nattress]

I did some FX1 60i to 24p conversions using Film Effects, www.nattress.com and the results looked very good - very 16mm film like. The results looked a lot better than the inbuilt 24p look, which to my mind is wrong because it doesn't put the right amount of motion blur into the simulation, which makes everything it shoots look like a battle scene from Gladiator.

Graeme

[Barry Green]

Yeah, I finally got the chance to view CineFrame 24 on a large-screen HD 1080i monitor.

It's useless.

CineFrame 24 is not, in any way, a film-look effect. It's a bodge of fields that produces a stutter effect, if that's what you want, but it looks completely un-filmlike. We shot 24P on the XL2 and the DVX side-by-side with CineFrame 24 on the FX1, and the difference is jarring (as was the weird strobing double-imaging mess that is CineFrame 24).

I've heard good reports from both Graeme and Marcus about their 60i->24 conversion software, so that warrants further investigation.

But if you want to make video with a film look in-camera, forget about CineFrame 24, it's not what you want and I think it was a mistake for Sony to include it in the camera -- they probably did it for marketing purposes, to "claim" it shoots at 24fps, but it most certainly does not.

[Graeme Nattress]

Thanks for confirming what I saw. It looked like judder-city to me. I'm pretty good at looking at a Film Look now and telling how it was done, and spotting when it's wrong. CF24 is wrong. It's very, very un-film-like. Now, how can I get Sony to buy my algorithm?? Or is it a case of "not invented here" with Sony.

Most likely it's just a quick thing they added in for the marketing dept.

Graeme

[Jeff Kilgroe]

<<<-- Originally posted by Barry Green : Yeah, I finally got the chance to view CineFrame 24 on a large-screen HD 1080i monitor.

It's useless. -->>>

There are a lot of people saying this, yet I've noticed most everyone complaining about CF24 has not done the 2:3 pulldown in post to convert to 24p. CF24 is not intended to be viewed without conversion to 24fps, so I'm a little puzzled as to why people are complaining so loudly about it as they stream it out of the camera to an HDTV monitor... Of course it's going to stutter and look like crap. :?

Now, that said, I've borrowed an FX1 and have been playing with it a bunch the past few days. I'm actually getting some decent results with CF24, however, I'm getting better results with 60i to 24p conversion. The CF24 seems to over-soften the image and the blur length doesn't look right. Doing a 60i to 24p conversion still isn't as filmic as true 24p, but I can get a lot more control and detail out of the footage this way.

As I have said before in other posts, I'm going to hold off buying at least until the Z1 arrives. I'll probably wait for NAB and see if Panasonic announces anything before committing... But I think that I will be buying either a Z1 or a PAL FX1 so I can shoot in 50i. The 50i video is still the same resolution and still encoded into the same 25Mbps data rate. But with 17% fewer frames/second, the actual compression level should be noticeably lower. I'd love to get my hands on some 50i footage to play with or a 50i capable camera to test my theories.

BTW: Love your DVX book, Barry.

[Barry Green]

Glad you liked the book, Jeff!

As far as CF24 and extracting 24P -- I know what you're saying, and I've heard that argument before, but frankly that argument just doesn't work. I know people are saying it, but I just can't agree.

CF24 is an in-camera simulation of 24P that's then written to tape with 3:2 pulldown, to approximate the look of 24fps film after it's been telecine'd to tape. Both the XL2 and the DVX shoot actual 24P, then implement 2:3 pulldown and write the footage to tape simulating how film would look after having been telecine'd.

Watched side-by-side, the DVX and the XL2 look like film. The FX1 CF24 looks "wrong". It isn't in any way filmlike. Furthermore, it gets much worse: CF24 introduces a pulsing, waving quality to the video -- shoot a resolution chart and you'll see that not only doesn't CF24 render motion properly, it can't even render a still frame properly.

No matter what you do or how you use it, CF24 is not at all filmlike. It's a weird stuttery digital effect, and if you want to use it for some "gladiator"-like weird look, then that's probably okay, but as a "film simulation" it simply doesn't work.

Viewing it at raw 24P wouldn't improve things any, because it's the creation of the 24 frames where the errors occur.

As far as you getting more success with 60i->24P, that's exactly what I'd expect. Trying to convert 60i to 24p real-time, in the camera, is asking way too much, apparently. But Graeme's or Marcus' programs can take all the time they need to do the best job possible.

And as far as Z1/CF25/50i, that's where the hope for the in-camera film simulation crowd lies. CF30 looks a lot better than CF24 does, so CF25 should look very nice indeed, and the slowdown to 24P isn't much of a big deal at all. Until JVC, Panasonic or Canon introduce a high-def 24P camera, CF25->24P is the high-def way to go.

[John Gaspain]

got this from mullens site http://home.earthlink.net/~dvcnyc/Sony%20HDR-FX1.htm

try this out and let us know if it fixes the "Strobing", I highlighted the most pertinant in BOLD below:

8. According to Sony USA, in CineFrame 24 mode, the camcorder uses DXP (i.e., DSP) to “synthesize a 24Hz temporal rate video from 1080i60.” According to Sony, the same intelligent deinterlacing employed in CineFrame 30, is used to create 1080 video with 30 frames-per-second. Then, according to Sony, 24fps is synthesized from the 30fps video. (Region 50 camcorders do not offer CineFrame 24.)

To record 24fps video to tape as 1080i60, pulldown must be applied. When 2:3:2:3 pulldown is applied to the 24 samples, 1080i60 video is generated. As shown in Diagram 11, 2:3:2:3 pulldown is applied to the 24 samples to generate 1080i60 video. (Six times each second, four samples are converted to five frames, yielding 30 frames.) By applying pulldown, 24fps video is carried as 1080i60 HDV video. With 2:3:2:3 pulldown, two judder frames (number 3 and number 4) are included within every five video frames.


Given the difficulty of converting 30fps to 24fps, it is possible that Sony has not yet fully disclosed how 24fps video is generated. (That may await a presentation at Sundance.) There are several alternate schemes that could be used:

a) The imaging system could be clocked at 48Hz, rather than 50Hz or 60Hz, yielding 1080i48 interlaced video. Then intelligent deinterlacing would be used to create 24 frames-per-second video that has no interlace artifacts. Once 24fps is obtained, 2:3:2:3 pull-down is applied. This would yield frames that are exactly 1/24th second apart. However, were the Sony to use this method, the available shutter-speed should be either 1/48th or 1/50th second. It is not.

b) A very intriguing possibility is that deinterlacing, rate conversion, and 2:3:2:3 pulldown are done during MPEG-2 encoding. By measuring motion between fields—using the encoder’s motion tracking logic—the following can occur:

I-frame: if “objects” do not move between fields—both even and odd lines within such objects are encoded thereby supplying these objects with full effective vertical resolution. When objects move—only their odd field is encoded so such objects have half their possible resolution.

P and B-frame: if “objects” do not move between fields—they simply are not encoded. When objects move—only their odd or even field are encoded so the objects have half their possible resolution. Fields are distributed via 2:3:2:3 pulldown in a way that results in moving objects having a frame-rate of 24fps. Naturally, the encoded video can be played on 1080i60 monitors—or down-converted to 480i or 480p. The Table below shows how this could be done.


Green text indicates fields that are copies of odd fields. Blue text indicates fields that are copies of even fields. Red text indicates judder (split) frames. The pattern of BPB above is repeated three additional times (plus a final B) in every 15-frame GOP (IBBPB BPB BPB BPB B-I).

By choosing fields from 60i interlace video that temporally match where 24fps would occur—60i video is converted to 24fps video. The period between samples that should be exactly 1/24th second apart—are not perfectly equally spaced in this implementation.

When CineFrame 24 is selected, you can must a shutter-speed 1/60th. You should not shoot in AUTO or use AE mode as the shutter-speed may rise above 1/60th and cause excessive strobing. (Unfortunately, the FX1 and Z1 do not offer the option of a 1/30th shutter-speed option.)

The advantages of Sony’s approach to 24fps video are twofold: light sensitivity is increased by 6dB (1 stop) while image noise is reduced compared to utilizing progressive scanning. It remains to be seen how the relatively high shutter-speed of 1/60th second will affect shooting for film. Shooting CineFrame 25 has the advantage of a 1/50th shutter-speed, which is very close to the typical film shutter-speed of 1/48th second.

While some may feel CineFrame 24 has a film look, the mode may best used with reverse 2:3:2:3 pulldown that can be used to recover 24 frames in each second of video.

In theory, the eye will not notice the loss of resolution because moving objects are blurred anyway. However, it remains to seen how the deinterlacer handles diagonal-lines that are in motion. Typically, these lines take on a staircase look.

Diagram 12 shows how Reverse 2:3:2:3 pulldown can be applied to CineFrame 24 video. Clearly, the four samples can be recovered.

[Barry Green]

1/60th is the slowest shutter speed the FX1 allows when shooting in CF24. Any faster would certainly make the problem worse.