35mm Filmout of HD-100U report

[Stephen van Vuuren]

I was fortunate to see a 35mm filmout of 720p 24fps HD-100U & Z1 (shot 1080/50i, deinterlaced in post, slowed down to 24fps) professionally shot footage - filmout by Duart. This was projected in top quality private theater (NC School of the Arts filmmaking) with several pro DPs in attendance. They HD-100U camera was there (as was a XL H1 but

HD-100U footage was overwhelming winner on all accounts - resolution, color, motion signature, latitude, noise. AFAIK, they took much care on the detinterlacing. However, "winner" does not mean "great".

HD-100U mediocre to poor job on green screen footage despite trying several methods of keying. On the 50 FT tall screen, stairstepping reached out and punched you in the eye. Color fringing also is much more serious at that screen size, so overexposure of highlights is death for filmouts. Stock lens issues on the HD-100U were obvious at times but no SSE in this footage (though they said it occasionally still occurs, but much less than first models).

We also go to see HD-100U footage digitally projected straight from camera tape on the same screen at the same size using a pro digital projector (unsure of model, but a very nice one). The digital footage was better than the 35mm in all regards. Accept that you lose a little rez, a little color, introduce grain (grain + video noise = ugly), a little latitude when going to 35mm film, so project digitally in HD if you can.

One other interesting note is the 720p footage was not stunningly more sharp than my 480p Thin Mode DVX100a 16:9 footage when run through an excellent quality uprez. It's not CineAlta-like rez for sure. Just more like really crisp 480p.

Details were sharper and crisper for sure, but due to focus challenges of shooting with the HD-100U in the field, softness was issue at times due to slight out of focus, so I can't say I was "awed" by the HD-100U footage, despite the large quality projection.

So, bring a HD monitor on set to shoot with these babies and/or mount a true 720p LCD to camera esp. if you are headed to the big screen as focus issues will kill you.

[Paolo Ciccone]

Originally Posted by Stephen van Vuuren

On the 50 FT tall screen, stairstepping reached out and punched you in the eye.

That is similar to my experience. I wonder if anybody had found the reason for this. Once you set the key, the stairstepping is very obvious. Is this a side effect of the HDV compression? Is it mitigated if acquiring the component signal?

[Stephan Ahonen]

It's because HDV stores chroma at a lower resolution than luma, half in each direction. I believe capturing off the component outs would give you the original chroma resolution back. I believe some of the more advanced chroma keyers out there like Ultimatte ($1,500, better bend over) can also compensate for lower chroma resolution.

[Paolo Ciccone]

Originally Posted by Stephan Ahonen

It's because HDV stores chroma at a lower resolution than luma, half in each direction. I believe capturing off the component outs would give you the original chroma resolution back.

Thank you Stephen. I'm aware of the 4:2:0 system and in fact I was wondering if the stairstepping is caused by approximation of the green been sampled at 2x2 pixels. When looking at the keyed footage the stepping seems much coarser than the resolution of the camera.
I'd like to hear the experience of people who tried chromakeying with the component signal. Anyone, anyone? Bueller?

[Brian Luce]

Originally Posted by Paolo Ciccone

That is similar to my experience. I wonder if anybody had found the reason for this. Once you set the key, the stairstepping is very obvious. Is this a side effect of the HDV compression? Is it mitigated if acquiring the component signal?

Well that sucks! Is it at least better at keying than mini dv?

[Stephan Ahonen]

Paolo, I've seen a little bit of the stuff you've done with virtual sets and your keys look fantastic. Any particular way you got around the blocking problems?

[Daniel Patton]

Stephen,

Thanks for posting your findings, it's good information to know. I'm sure a lot of people have been wanting to hear more about filmout experiences, I for one have.

But one thing bothers me about this, and more than just a little I might add. First, why would ANYONE go through the trouble of doing a filmout using the HD100's stock lens? It's simply a good cheap lens that at times is barely good enough for HDV recording/playback but I cringe at the thought of shooting something that would be shown at that size with it. I would at least expect that someone use a better lens like the 13X... or something? Otherwise you are blowing up footage from what I believe is a great camera (for the money, even more so) but with a so-so quality lens. So I would expect it to look exactly as you described. In fact, I can see that for myself on a 24" HD monitor if I look close enough.

Second, someone did a filmout from keyed footage from the tape transport? Why in God's name would they do that? Why stop there... downsample to DV, run the key, and then last do the filmout. Hehe... believe me I'm laughing while typing this, so please do not take my rantings serious.

This IMHO just sounds like a bad use of a factory camera setup. Please, please someone use a good lens and a drive/file system via component so we can see the HD100 as you might expect when going to film.

Thanks again for the head up Stephen.

Peace

[Tim Holtermann]

The higher the resolution the better the key, period. I spent years compositing footage for a Matte Painting house in Hollywood and have had to pull keys from the best 4K and 2K Cineon frames to horrible DV footage to mix into 35mm scans.

I had to use everything at my disposal to get a good key but it's more than just clicking a key button in some software package. There is an art form to pulling a good matte with the right amount of key choke, blur, etc. Usually I used Ultimatte in After Effects, but also used keying in Flame, Chalice, and Shake. If possible try starting with Ultimatte and experiment, experiment, experiment.

The chroma being 4:2:0 doesn't help but it's not the main reason your getting stair steps. I've seen it on 4:2:2 too. Usually when pixel shifting is involved because of the "inherit" resolution. Also, any time you put something up on a large screen you will see it's limitations, even native 35mm 2K keys are sometimes noticable if you know what you're looking for.

[Stephen van Vuuren]

Originally Posted by Stephan Ahonen

I believe some of the more advanced chroma keyers out there like Ultimatte ($1,500, better bend over) can also compensate for lower chroma resolution.

One of the shots was done with Ultimatte.

[Stephen van Vuuren]

Originally Posted by Daniel Patton

Stephen,
First, why would ANYONE go through the trouble of doing a filmout using the HD100's stock lens?

The camera was on loan from JVC and they were evaluating for use in the feature. The film out was around 3 minutes long for each camera which we watched 3 times. They agree it was cheap lens but are considering it anyway (i.e. DP does not like it but the producer thougt it was "okay".

Second, someone did a filmout from keyed footage from the tape transport? Why in God's name would they do that?

This was a test, not a final product. They sent in both well exposed, well focused shots and under/over exposed to see how it held up. They wanted to see if/how HDV keyed. They seemed happier than I was with. I thought the film grain made the keying artifacts worse.

I assume they would do component out, but 4:4:4 uncompressed 720p can become a budget/workflow/time issue depending on how much it's used, so many people may key HDV.

But you don't have to convince me. I have not bought any of the 1/3" HD cams due to various compromises each pose. But since my current project is 1080p uncompressed, I have the luxury of not having to buy right now.

[Daniel Patton]

I could see why the DP might not like it, I'm sure I would lean more towards his take on it. ;)

Don't get me wrong, I can get a good key from the HD100 for delivery to HD LCD's etc., and it looks very good. But never would I do this via tape knowing it was intended for filmout, nope.

I could race my Mazda RX8 stock, but having a third rotor, tweaked & tuned suspension, with fat wheels would make the car sick with performance.
I hope they, someone, anyone does a filmout with the HD100 and that they do it right, if you know what I mean.

Peace

[Brian Luce]

Originally Posted by Stephen van Vuuren

The camera was on loan from JVC and they were evaluating for use in the feature. The film out was around 3 minutes long for each camera which we watched 3 times. They agree it was cheap lens but are considering it anyway (i.e. DP does not like it but the producer thougt it was "okay".



.

What other cams did you guys test?

[Stephen van Vuuren]

Originally Posted by Brian Luce

What other cams did you guys test?

I did not do the test, just invited to see the footage. The also had filmout form the Z1 in 50i mode.

[Paolo Ciccone]

Originally Posted by Stephan Ahonen

Paolo, I've seen a little bit of the stuff you've done with virtual sets and your keys look fantastic. Any particular way you got around the blocking problems?

Hey Stephen, thank you. Believe it or not, I shot that first Vodcast pretty much improvising and with just "emergency lights". I'm putting together a proper light kit that should help. I'm mentioning this only to underline then fact that the screen was not properly lit, and I had a ton of spill on me.

The keys were pretty good but the stairstepping is defintely visible when you work on the footage. I used Ultra 2 for keying and dialed the "Soften Matte" a bit to remove the edge. Everything else was tweaked eldlessly, paying a lot of attention to color shift, brightness of the subject compared to the background etc. It's my first attempt at something that long all done in green screen so there a lot of room for improvement but at least it's watchable (or so I've been told ;))

[Steve Mullen]

Originally Posted by Stephen van Vuuren

Details were sharper and crisper for sure, but due to focus challenges of shooting with the HD-100U in the field, softness was issue at times due to slight out of focus, ... .

I'm seeing a many out of focus shots on network episodic HDTV. Looks like when shooting rapidly, even "pros" have a problem with focus when shooting CUs.

I'm now zooming out slightly after I think I've got focus on a CU -- adds just a bit of extra DOF that overcomes any focus error I may have made.