Which option to take for greenscreen?

[Chris Smith]

I personally don’t see the point of the hardware key. It just opens you up to less options when you get your footage dumped in. Sure DV isn’t great with color, but putting an electronic green on a tape is no different than a well lit green in the first place. I would just light it as well as you can and pull your key in software where you have total control.

Chris Smith
https://www.sugarfilmproduction.com

[Eugene Perepletchikov]

Hey Chris

I guess that that’s what i was thinking too, that even if it was a perfectly even green, the problems on the edges would remain as it is still dv compression. Although, a totaly even green could save me a bit of time in regards to keying…

I guess that I will evaluate the test footage and see where to go from there. I understand that dvcpro50 footage would make a big difference, I just have to see whether it will justify the costs…

Have you had any experience keying dvcpro50 footage? Does it come up a lot cleaner after a reasonable amound of processing (colour grading, blending modes etc)?

[Joseph W. bourke]

My feeling is that DV footage is never going to give you a great key. We have the option, which apparently you don’t, of shooting on BetaSP whenever we need to pull a key. We have older BetaSP cameras, and DV25 is our “newer” (but in my opinion, barely broadcast) acquisition format for news.

The 4:2:2 that Beta gives you just gives way more information to the keyer, whereas the 4:1:1 of DV25 gives you artifacts in the key cutout, pretty much no matter what you do.

Here’s an article in DV Magazine (I think you have to sign up as a user – for free – to access it):

https://dv.com/news/news_item.jhtml?LookupId=/xml/feature/2003/jackman0603

This will give you the skinny on why DV is an inferior format for keying. Good luck!

Joe Bourke
Art Director / WMUR-TV

[Chris Smith]

No experience with it. Can’t say I’ve ever used DV in production either, but there are tons of projects being done with DV and keying. Yeah, it’s not the ideal format for sure, but there has been tons of ppl that have made successful comps using DV and keying. So I personally wouldn’t go insane getting overly technical and too worried with the format. I however would try to get a good shoot with good lighting and such.

Few tips:

Use a large studio or outside open area to get the subject far away from the screen. Use long lenses on your cam if possible and back your cam up from the subject. This ensures no spill, and the long lens/distance from your subject to screen decreases your DOF putting the greenscreen more out of focus. Also you are now seeing a small controllable area of the screen so you don’t have to light a large portion of it.

Other hints if you just don’t have the lighting powewr is to shoot it outside and let the sun evenly light it. Then work with black blankets to subtract ambient light (called negative fill) from your subject.

Like when I do greenscreen stuff, I often put the subject 10 to 20 feet in front of the screen. Then the cam another 10 to 20 ft away from the subject.

Chris Smith
https://www.sugarfilmproduction.com

[Ron Lindeboom]

The best keyer for DV footage that I have ever seen, is Boris FX’s keyer. It seems to be developed for DV footage and you can often get a successful key (well, for DV footage, anyway) in two passes.

Ron Lindeboom

[Jon Walker]

I have pulled some very acceptable keys using DVCPro 25 and Keylight in After Effects. Lighting is your key element here. Sure great cameras will pull great keys, but if your lighting sucks you’re no better off. dvGarage has a great plug in for After Effects called dvMatte Pro. There is also a version for Final Cut. You can read more about that here https://www.dvgarage.com/prod/prod.php?prod=dvmatteae It uses luma information instead of chroma info to pull keys from dv footage. Since the chroma values of dv are so crappy, it takes info from the luma channels to decrease spill and enhance edges. I haven’t used it but have heard great things about it. It is all in the set up though no matter what you use. Evenly lit green screens with well lit subjects will always beat any piece of software on a badly lit key. I have also had experience with the hardware key but I personally didn’t like that at all. If your subject is wearing anything even close to green it will be twice as evident with the hardware key and will be stuck in your footage. You won’t be able to roto out any problem areas because your source footage is already keyed once for the hardware green screen. Stick with your regular green screen and focus on lighting. That can never be said enough. Good luck.

– Jon Walker

[Eugene Perepletchikov]

Thanks for all your responses guys.

I have had some experience with greenscreen in the past and agree with you guys that lighting is crucial! Luckily i am shooting in a proper studio environment with excellent lighting capabilities.

I have made the final decision to go with the DVCPro50 format. In reply to your comment Joseph, DVCPro50 is actually 4:2:2, running at 50 Mbits/sec and would match, if not outperform the older BetaSP format, judging from examples of footage that I have seen.

I would maybe have considered sticking with regular DV but time is a big factor for me too. If I have to spend 4 times longer to pull a clean key (on over 80 seperate shots for good measure!) than that is a big problem. I have fun times ahead, keying footage,finishing textures+lights for environments, matching camera moves in 3D, compositing, colour grading, visual effects, editing, sound design…anyways, enough whining from me!

Thanks guys!