Best Cam for blue/green screen
 

Hi

I use a canon XH A1 but it's not high enough quality for pulling nice mattes when using blue screen and green screen for VFX work.

I have a project coming up and wanted to know if anyone on here had experience and what would be the ideal HD cam to use for this. The final output will be SD res or slightly larger but I would prefer to use an HD cam that is 4:4:4 or RAW so there is no degradation in quality and then scale it down before final output for a very crisp image. I was thinking about renting a RED one cam for this but wanted to know what other people were using rather than just guessing.

Any info will be appreciated

thanks

D

I haven't really done any intensive VFX work, but you should check out the products over at dvgarage.com. I know they advertise them as being capable of pulling effective keys from DV footage. You might have better luck using that with your XHA1.

Also, from everything that I've read, 4:4:4, while ideal, would probably be overkill for everything except film work. 4:2:2 has usually been recommended for most situations. If I remember correctly, someone on this forum was able to use the component output from the XHA1, convert it to HD-SDI, and run it into a capture device. I believe it was within the Convergent Design Flash XDR subforum of the tapeless forum.

The HDMI outputs from the HV20 and HV30 are also supposed to be 4:2:2 outputs according to Alex Lindsay from The Pixel Corps. If you have a Mac Pro, then you can purchase a capture device to capture the HDMI output of the camcorder, then use that for your VFX work.

Best of luck!

Hi

I know how to pull mattes, I've been doing VFX work for a while, but it is more work when the green and blue channels aren't full quality and more has to be done by hand whereas top quality footage can have mattes pulled with plug-ins with little to no cleanup. Plus the XH A1 isn't true HD and even though the quality is damn good for the price it's just not the same.

Besides all that, the project will have a proper budget to rent a cam and lenses and all the necessary gear for a few days for the shoot. I'm more concerned with what gear has been tested and proved effective in a production.

Also, I have a mac pro and it doesn't have an HDMI input. I can use firewire capture through final cut pro but a 3rd party capture device would be needed for HDMI.

Thanks for the info though. Maybe I can find some info in that forum.

D

Alright, I did some research on this and came up with some information.

In order to capture HDMI to the Mac Pro, you would need to get a Blackmagic Intensity card. The standard Intensity card will run you $250, while the pro model (which I think only adds additional analog inputs) will run $350. Here's a link to their website: Blackmagic Design: Intensity

According to one forum (Capture HDMI From Camcorder), the video output over HDMI is straight up 1920x1080 4:2:2 uncompressed. Here's an email that one of the users in that thread posted. It comes directly from Blackmagic:

"When the camera is connected to our products (via HDMI or component), the camera will do a process called un-line decimation that will allow for the original 1920X1080 to come out over HDMI or component directly to our card so you are capturing the original 1920X1080 that your footage originally was. Hence, working with uncompressed footage."

So, it seems like that route might be a viable one if the quality would be up to snuff, and if you are able to have the camera tethered to your Mac Pro while you're shooting in order to import the footage directly to the Mac (otherwise, if it's recorded to tape, then you'll just be playing back compressed footage through the HDMI output).

Best of Luck,
Glenn Fisher

I would probably have to record directly to disk or onto a laptop, and I'm not sure if the laptop I have (macbook) would do be able to capture it as I don't have a macbook pro laptop and lugging my workstation to a location isn't practical.

Unless those hard drives you can attach to an XH A1 provide the same uncompressed quality, or the macbook could capture full HD, I think renting the gear would be the safest bet.

I appreciate you doing some research though. I'm going to checkout the black magic card.

thanks

D

Hi Darren,

I have the new Canon XL-H1S along with the AJA IOHD.

This systems allows me to capture HD-SDI RAW video to ProRes422HQ on my Macbook Pro for virtually uncompressed 1080p HD. This is more than good enough for what you are looking to do (assuming the lighting is right).

Feel free to contact me if you'd like my help or services ... I'm in NYC as well.

Well I'm no VFX star, but I shoot a ton of Green Screen with my XH-A1 and don't have a problem pulling keys. Of course we light properly and have a good keyer.
Plus the output from the XH-A1 can be captured uncompressed into my Kona card for high quality work.

Good Luck!

I second that. I shoot Green Screen quite often just using the HDV from the A1. As mentioned, proper lighting and a good keyer are essential. You can also take the uncompressed analog component output from the A1 with the appropriate card.

David, I know about the IntensityPro cards but what is a Kona card?

You may want to look into a true progressive camera that offers no resolution drop when shooting progressive. Progressive keys so much better than interlace. Recording to a decklink card or flash xdr via HD-SDi will be better quality than either HDMI or component.

How about using an EX1 and taking using the HD-SDi output.

I would also consider a Panasonic HPX170, or 200a, as they are also progressive chips, with 4:2:2 color, as opposed to 4:2:0.

The recording codec is 4:2:2, but the front end of the camera can't produce as much vertical chrominance resolution as luminance - that's the whole essence of how pixel shifting works. That's not a criticism of the camera as a whole - pixel shift techniques mimic the way the eye works, better luminance perception than chrominance - but it does mean that for this specific case the camera wouldn't have any real advantage overall.

Keying is also as much dependent on luminance resolution as chrominance, much better to go for a camera with higher resolution native chips and 4:2:0. Or ideally make use of an HD-SDI output to make a less compressed, better colour space recording externally.

pick up a used JVC HD100 or HD110. Live 60p uncompressed outputs then capture with a video card. Of course you need to capture with your computer durring taping to bypass the HDV encoder, but more than a few people do that.

I have been looking at cameras for pulling clean keys for over a month now. The Sony EX1 has gotten nothing but great reviews especially if you pull a ProRes HQ 4:2:2 Intraframe from the HD-SDI port into a AJA card.

We are purchasing an EX1 since we will be doing a ton of greenscreen work. I am sold on it. It is also Discovery HD Silver approved. The 1/2" CMOS is full raster and appears to win out even in its native 4:2:0 codec versus a 1/3" uprezzed CCD with 4:2:2 sampling.

Get an EX1, take a look at this thread.

Edit:

#7 by Basilisk - "I always use the Sony XDCAM EX1 - and it is the best footage for keying I have had the pleasure to use...Critics will argue about its 4:2:0 colour space and compression artefacts, but given the quality and resolution of the sensor, these are minor..."

#26 by VelocityVideo - "I'm tickled by the EX-1 for chroma-key work. Granted, we came from the DV world, but it really is quite fantastic."

#29 by Basilisk - Link to this commercial keyed from footage shot on a EX1.

#35 by Adolfo Rozenfeld - "I got incredibly good results for keying using an EX1 connected through HD-SDI to an AJA IO HD ... The keying quality is nothing short of amazing."

#36 by Finegrit - "I've recently done a ton of greenscreen work with a bunch of different cameras and shot by crews ranging from small indie-DIY crews to top-level pro DPs with union crews....On a budget and can't afford anything more: The Sony EX-1. Nice clean images. Some compression artifacts, but very nice for the money."