FS700 + O7Q chromakey recommendations

[Pgale]

So I've not shot any green screen footage with the FS700 and O7Q at all yet. I've got my first chromakey shoot in a while next week.

I'm wanting to shoot 4K2HD, the subject will be simple talking heads. RAW probably isn't an option as I'm sure the content will exceed my current recording capacities and I don't really want to have to offload on set.

Any advice or recommendations?

I will be doing some tests later but wanted to get your advice first.

Many thanks!

Paul.

 

[Pgale]

Ah I only just noticed this thread which gives me most of what I want:

http://www.dvxuser.com/V6/showthread.php?322990-4k2HD-For-Green-Screen&highlight=greenscreen

Now the question is whether to shoot REC709 or SLog2.

Any other recommendations most definitely welcome though.

Other thing is that my extensive collection of lighting is still tungsten. Been holding off LED until it gets better. OK, some of the high end units aren't too bad but there's an awful lot of c**p out there too. Any recommendations for nice even fixtures to light a small popup screen?

 

[Gene Sung]

Now the question is whether to shoot REC709 or SLog2.

REC 709 is not really useable IMO. Check out the pic I attached. On the 7Q, it has a problem with aliased, magenta highlights that I've run into over and over. Yes, this shot is over-exposed, but it just doesn't handle highlights well, which probably is not an issue with green screen but I would avoid Rec 709 unless it got fixed in the last firmware update.

Rec 800, is just really noisy from my tests, on both AVCHD and 7Q.

The only useable profile at this point is S-Log. I've shot quite a bit of S-Log green screen lately and it works well. Just put some contrast and saturation in post before you pull the key, they use corrected key image as the matte to the original S-Log image.

 

[Pgale]

Hey thanks Gene,

TBH I've not really shot any 709 on jobs with the O7Q - it's all been SLog2, so your advice is very useful - thanks

 

[paulcurtis]

As Gene points out very well - Slog2 is fine for keying, in fact it's quite useful just to give whoever is doing the keying the Slog files because they can grade a version of the file for just pulling the key - there's a bit more you can do with Slog than a baked in Rec709. Certainly that's a real advantage of keying RAW (the ability to 'develop' different looks for different uses).

cheers
Paul

 

[Pgale]

I'll be doing the edit too - so no problems there!

I've got a 3x set of the cheapo F&V K4000S LED panels coming in tomorrow - will be interesting to see how good (or not) they are. I really didn't want to get 2-3KW of lighting in there as it'll be a fairly small room and will get a bit sweaty!

 

[paulcurtis]

I'll be doing the edit too - so no problems there!

I've got a 3x set of the cheapo F&V K4000S LED panels coming in tomorrow - will be interesting to see how good (or not) they are. I really didn't want to get 2-3KW of lighting in there as it'll be a fairly small room and will get a bit sweaty!

Well if they're like most LEDs that green spike might come in useful I should have suggest fluorescent though, quite easy to light screens with that, the LEDs aren't that soft unless very heavily diffused. But i'm sure it will be fine. For future reference if you can, try Remote Phosphor based LEDS, truly excellent quality and there are even phosphor panels especially for green light.

cheers
Paul

 

[ChadN]

I recently shot chroma key in Slog2 and thought it was great. I followed some simple rules learned from that other thread.

Using false color, and the included LUT... i lit the screen to fall mostly in the green area (50%). Lit the talent to have skin highlights in the yellow (70%). (remember that's with the monitoring LUT ON)

Stopped down to below f5.6, maybe even f8 if you have enough light.

Shutter speed of 96 (rather than 48 for 23.98fps) less blur to deal with.

In post, i actually keyed the slog2 footage first. Then color corrected. Didn't even have to add saturation or contrast before keying. though it might help if you have troubles.

If you can, use Neat Video or some noise reduction software BEFORE the key.

I'm no pro and just do this for fun at home, but using the above tips yielded the best results i've run across personally. Overall, i thought Slog 2 4k2HD was excellent for chroma key.