XF100 Picture And Noise Issues

[Aaron Miller]

I am using the XF100 primarily for greenscreen use. I got it specifically because of the 4:2:2 color space. I will first say that the chromakeying seems to be more than twice as good in terms smoothness on the edges.

My main issues right now with the camera (and these have been pointed out by a review I read somewhere) are:

With no color profile selected there is some significant sharpening going on. My subject has a white line around them and that is only because of some kind of sharpening algorithm.

The skin tone is terrible. Very orange.

NOISE. I have 2000 equivalent watts of fluorescent light directly on the person and at least 2000 on the greenscreen.

All of these issues are workable. I can color correct the skin tone and we figured out how to reduce the noise by going -6.0db and 2.8 fstop.

I am using 3 canon hm400 cameras for other angles and I was under the impression that all these cameras use the same chip. The hm400s don't key as good but the color reproduction is way better and also there is almost no noise compared to the xf100.

Is anyone using this camera for serious green screen work and if so do you like it and do you have workarounds/recommendations for these issues?

FYI this is my first pro camera and I really wanted to send it back after viewing the first bit of test footage. I don't understand why it has to be at -6 db of gain to get decent footage. I have had thoughts that maybe with all the trouble in Japan some cameras come out better than others and I have a bad sensor??

Here are some sample images with no color profile, -6db gain, 2.8 fstop:

Photo Album - Imgur

I don't have access to the meta data tags

Thanks

Aaron

[Pete Bauer]

I'd just take a guess and say that your color temp is on the high side vs your lights if the skin tones are notably orange, and yes, I'd definitely bother to turn down the sharpening.

I'd never been satisfied with my amateurish efforts at green screening in the past but between the XF105 and PPro, it was "no-brainer easy." I did turn down in-camera sharpening, but otherwise just shot my talking head and used UltraKey right within PPro and it turned out quite nicely for a "quick n dirty" green screen. A couple examples of this are the Multicam and Dynamic Link tutorials in the articles section of DV Info Net. Skin's not orange; pretty close to my actual pale/ruddy look.

I'm not familiar with a Canon HM400; might you mean JVC? Anyway, I'd be pretty sure it does not have the same chip, and certainly not the same processing algorithms, as the XF cameras.

[Pavel Sedlak]

Originally Posted by Aaron Miller

FYI this is my first pro camera and I really wanted to send it back after viewing the first bit of test footage. I don't understand why it has to be at -6 db of gain to get decent footage.

Canon cameras are famous with this gain issue, -6dB gain is the same input as 0dB gain for others cameras - http://thebrownings.name/WHP034/pdf/..._XF300-305.pdf
page 15 (at the end 2.4):
"...Perhaps the designers would have been better advised to reduce the head amplifier gain by about 6dB,
resulting in a sensitivity of F/9.6 and returning noise levels 6dB lower (around -50dB)."

The "pro camera" has not only "pro records", but also It has "pro glass" and "pro chip" and "pro DSP processing". The XF100 has "pro record" but It's glass is not as good as XF300, the 1/3" chip is not "pro" too.
For serious greenscreen work on the broadcast level you need some better input signal, XF100 isn't the correct input for this work, it is low documentary cam and I'm satisfied with it (XF100 has 50Mbps/422 record because it is "B cam" for XF300, the quality of this record is not balanced with quality of the glass and chip XF100, it has more quality for the same workflow with XF300 like Sony PMW100 and PMW700).

[Aaron Miller]

Originally Posted by Pete Bauer

I'd just take a guess and say that your color temp is on the high side vs your lights if the skin tones are notably orange, and yes, I'd definitely bother to turn down the sharpening.

I used 5500 Kelvin which is what my lights say...maybe they aren't accurate? Either way the Canon HF M400s that I used as b-cams have accurate skin color.

Originally Posted by Pete Bauer

I'm not familiar with a Canon HM400; might you mean JVC? Anyway, I'd be pretty sure it does not have the same chip, and certainly not the same processing algorithms, as the XF cameras.

Sorry I bungled the name it is the Canon HF M400. From what I can tell on canons website with the comparison feature both cameras use the CMOS HD PRO censor.

I was going to try turning down the sharpening but wonder what the picture will look like. To be honest it seems like the only 2 things the XF100 has over the HF M400 is great XLR inputs and 4:2:2 colorspace. If I wasn't using greenscreen I couldn't recommend the XF100.

[Mike Ayotte]

Take a look at this site: WarmCards - White Balance Reference System. These cards & his video tutorials for the XF 300 have helped me as much of it applies to the XF 100. I am not having any problems pulling great green screen keys in Avid Media Composer 6.01 using Spectramatte.

[Steve Jordan]

Good day all.
I recently got my XF100 overall very happy but I need to do some green screen work and my tests are less than satisfactory. The raw footage looks great, a tad pale/cyan but using RGB curves corrects that nicely. Thing is when I import to Adobe Ae (CS6) and use Keylight 1.2 to knock out the green I get a lot of noise on the rest of the footage. If I adjust the screen matte Black and White clip it does not get any better. The initial color selection (using the eye-dropper) seems to leave a blotchy residue on the remaining imagery. I can send a 300mb copy of the Pr/Ae files via Yousendit or Dropbox if anyone would be willing to take a look.

[David Dixon]

The XF100 doesn't really shine until you adjust the Custom Picture files. I recommend either shooting very flat and adjusting saturation, black levels, sharpness, etc., in post, or setting up a more saturated, contrasty, "finished" look in-camera.

I recommend limiting Gain (exposure Gain, that is) as much as possible and keeping the iris fairly wide open.

I find if I use saturated colors but only moderate sharpening, green screen is dead simple (I use FCPX), even with less than perfect lighting. I've never used Premiere but it just sounds like the settings need adjusting on the key.

No, the XF100 lens is not as good as the XF300, but it is better than Canon consumer cameras. The customization, XLRs with very good audio preamps, waveform monitor, 4:2:2 color, undercranking/overcranking, small size, infared, etc. make this a very powerful camera *if* you dig into its capabilities and learn it. It still has features I would miss in many $5K cameras.

I do wish they would come out with an improved version with a little better low light, built-in NDs, and 60fps @ 1080 instead of 720, but at $2500, it's still more than competitive in its <$3000 price class.

[Steve Jordan]

Thanks David.
In the intervening weeks I ended up (on Canon's advice) using the standard settings but reducing the gain to -3, exposure was about a 1/3 of a stop over. The real trick though was to swap "Soft Color" replacement to "Hard Color" in Keylight (Ae plugin). Also, I ended up buying a new green screen background, 8'x16'. It is a pop-up style that is 8'x8' with a "skirt" than can be used as a floor cover. The other "trick" I worked out was to bring a few sheets of black material to tape to the pale walls (shooting interviews in relatively narrow conference rooms) to cut the green hue reflected off the walls onto the side of subject's face.