Consumer cameras for green screen

[Oren Arieli]

A friend of mine has converted his garage to a green screen studio and has asked my advice. He is looking for a consumer or cheap prosumer camcorder with a robust codec that can record footage suitable for a clean key. Ideally, it would be to SD, CF card or hard drive.
He plans on putting together an edit system based around a Blackmagic Intensity Shuttle card, so my suggestion was to capture via HDMI out to the BM card running on a USB 3.0 capable laptop. This requires a relatively new laptop, but eliminates the need for a professional camera. Assuming a rock-bottom budget, would this be a better route than a prosumer camera recording internally?
Any other suggestions I can pass along?

[Chris Medico]

When you say rock bottom budget.. Can you put that into perspective? $100, $1000, $5000?

[Ken Hull]

Oren,

Well, ideally, a camcorder for green-screen work would have 3 full-raster sensors (CCD or CMOS), and record with color encoded at 4:2:2. The least expensive camcorder I know of that delivers that would be the Canon XF300, which goes for about $6500. Increasing your camcorder budget to around $9000 would get you the Panasonic AG-HPX370.

Another option would be to get a full-raster 3-sensor camcorder that has HDMI out, and hook it up to a $3000 nanoFlash recorder. (BTW, Atomos says they will soon have their Ninja recorder available for sale, at about $1000.)

Other than the above expensive options, your friend could simply get a good 3-sensor camcorder.

(And, of course, be sure to light the green-screen evenly.)

Ken

[Seth Bloombaum]

We tested a Sony V1 3-chip prosumer camcorder, outputting 1920x1080 to an Intensity Shuttle via HDMi, versus a Canon 7dMk2 with kit lens, with conventional workflow, for green screen last week.

Our findings were that yes, the 4:2:2 uncompressed capture was easier to key.

However, we liked the picture from the 7d better. After running it through Keylight in After Effects, the key quality was excellent in both. So, we're sticking with 1-chip dSLR for the next set of projects. I'd expect similar performance from the T2i and um, what was that new canon? 60d?

That's an $800 solution plus lens.

Of course, there's no substitute for good keying software, no matter what your colorspace is.

"Everybody knows" uncompressed capture via HDMI is better for greenscreen. I'm a big believer in testing these things.

[Pete Cofrancesco]

I was never able to get professional results using prosumer sub $4,000 camcorders. Proper lighting and setup will make things easier. In my opinion its a difficult and expensive proposition and I'd put the bulk of your money into the lights and 4:2:2 color camera. I'd be curious how a DSLR would key.

[Oren Arieli]

Thanks Ken and Seth. I'm not sure what his budget is, but if he's considering consumer gear, my guess is that he's hoping for good results under $1K. I wasn't sure if a DSLR would do the trick, but my feeling is that DOF is not a concern, nor is adequate light levels. So what is the benefit of a DSLR in this fixed-location setting? Wouldn't moire and edge detail be more of a concern due to down-sampling and pixel dumping?

His current camera is a 3 CCD, but SD (not a big deal). The problem is that he can't take a firewire out from his older camera, nor can he record on memory cards for faster ingest.

The Ninja is on my wish list for sure. Maybe I can purchase one and rent it to him ;-)

[Chris Barcellos]

Have him do himself a favor and beg, borrow or rent a little T2i or T3i, and shoot it well lit in his green screen studio. You will be surprised at how well even that little camera does. It gets noisy quick, but if you light it for low ISO, it will excell. Then convert with Cineform for maximum capability on the edit side, and you will do fine.

[Oren Arieli]

Thanks Chris. I'll pass these suggestions along to him. And in looking back at my last post, I have to correct the 'firewire' output statement. I meant to say HDMI out.

What we need is quantifiable results. Otherwise, there might be too many variations at play (quality of lighting, ingest, software, etc.) This whole thread gives me an idea for our next PVA (Professional Videographer's Association) meeting. A green-screen all star shootout. BYOC (Bring Your Own Camera).

[Seth Bloombaum]

The shootout is a great idea. Test and benchmark!

Pete was curious as to how dSLR footage keys - typical dirty key, similar to other 4:2:0 cameras. Meaning that, if you light and block well for greenscreen, and use a keyer with good spill suppression, it's just fine.

This assessment is based on actual tests, and comparisons to HDV from a V1, HDMI uncompressed from a V1, HDV from an HD100, and native recording from a 7d.

We're using one of the excellent non-woven foam-backed screens, evenly lit per scopes. Keylight has excellent spill suppression, and the 7d looked great.

To expand on what I wrote above, in the sub-$5000 camera range, we like dSLR imagery best. We shoot a lot with 5d as well as 7d, love the look. So, if we can make the key work to pro standards, that's the end of the discussion for us. YMMV.

One setup I'd like to test is EX3 into ProRes422 via the SDI-HD KiPro, but that's significantly higher cost.

[Chris Barcellos]

We built a green screen 24 x 16 high, with another 16 x 16 right angle wing. We have a painted floor too, 16 x 24.

Spill from the sides and floor is a major issue in our first testing. Lesson learned is that unless you are needing it in the particular shoot, cover the floor and flag the side wing for easier key. I am sure the could apply to even part of the screen that is not in shot.

I am only using Vegas on board keyer. Any one have an a recommendation for a keyer plugin for Vegas that cleans up spill too ?

[Oren Arieli]

Thanks Seth. Sounds like you found a solution that works best for you. I just got off the phone with my friend and passed along these suggestions (he's not a member of DVinfo).

[Seth Bloombaum]

Originally Posted by Chris Barcellos

...I am only using Vegas on board keyer. Any one have an a recommendation for a keyer plugin for Vegas that cleans up spill too ?

IMO, the next step up from Vegas' native keyer is NewBlue's Video Essentials 2 keyer. The spill suppression isn't great, but it is there. and it has a nice shrink matte function. Really not bad for $100. It's been updated to the OFX standard for Vegas 10, so now all parameters are keyframeable.

The next step from there is rather steep, but it does get you into the outstanding spill suppression of Boris Continuum Complete, or, into After Effects which includes Keylight.

OTOH, if you're willing to put up with a terrible workflow, the freeware CineGobs keyer is fun...

I've been itching to see the re-released Ultra keyer, now in CS5. Ultra was always rather unique, in that you could easily and quickly build multiple key colors, plus great spill and easily controlled shadows.

I think all the above have trial-ware versions.

[Chris Barcellos]

Seth:

What is best workflow to get Cinegob to Vegas ?

[Seth Bloombaum]

Ugh. Well, it's been a while, but as I recall, CineGobs only wants to see AVI on the input side, and will only put out AVI.

For DV standard-def, that's easy - AVI-DV in and out, if you do the composite in CG. If you want to composite in Vegas, go to step 2a below.

For HD, the options are more limited to good Digital Intermediate codecs in AVI. That would be Uncompressed, Lagarith, and Cineform ($).

So, a workflow would be:
1) Transcode HD to eg. AVI-Lagarith in Vegas.
2) Cut a key in Cinegobs. Composite a still background in CG, and output to AVI-Lagarith for further editing in...
3) Complete your edit in Vegas.

Or,
2a) Cut a key in CG. Output as uncompressed AVI, 32-bit with transparency channel, for compositing in...
3a) Composite over backgrounds and complete your edit in Vegas.

That's what I remember... CG is great free software, but, even apart from this DI based workflow, is not real friendly. You need to know how to key, and interpret some of their controls.

PS. Although Lagarith supposedly supports a transparency channel, I've never been able to get it to work in Vegas. Don't think I've tried it in V10.

PPS. If you want to followup on this, you should probably start a thread over in the Vegas forum, where there is lots of expertise with DI...

[Chris Barcellos]

I've had Cinegobs for quite some time, now, but never took time to learn it. I updated to latest version.

I have been able to do most of the work in Cinegob, except, I have been having issue in trying to get a render with a transparency channel to edit in Vegas.

I do have to say that the spill clean up has made a big difference compared to what I am able to do in Vegas. I am quite impressed.

I am having one problem, and that is trying to set it up to render for further editing in Vegas. I have been trying to get out with a transparency channel using Cineform, and I am just ignorant of settings needed. I will keep trying as you appear to indicate it is doable. If you have any hints, let me know.