Shooting under Fluorescent Light

[Lucky Haskins]

I am in pre pro on a training film that will include a lot of shooting under (really bright) fluorescent (in a hospital ER).

I not really concerned about the ambient light (there are enough postings here stating that most have had no problem shooting with the EX3 in this environment) but I do have to do a lot of stand ups and am wondering about a key light.

I have to run and gun a lot in this and I am thinking about one of the 12x12" LitePanel LEDs.

They tend to throw off a cooler light that would seem to a good fit in this environment.

Thoughts?

(I will post this over in the lighting thread but wanted to check in the EX3 group first.)

[Denis OKeefe]

You might consider using a warmer light, either the LED with a gel or a tungsten lamp. It will warm up the skin tones. A flag or scrim out of frame over the head of the talent will reduce some of the fluorescent top light off the hair too. If you wanted to get real fancy sandwich a warming gel with a scrim or silk over the talking head. I use a microlight on camera or slightly off to the side to put some flesh tones into the shot, works like a charm.

[Brian Cassar]

Use a Zylight 90 - first white balance on existing fluorescent light, then dial in a slightly warmer colour temp in the Zylight to warm up skin tones. The Zylight is incredible for such situations. Also consider the use of warm cards to white balance the dreaded fluorescent light.

[Lucky Haskins]

I actually ran a test using the Vortex Warm Cards (fluorescent version). Really killed the ambient green.

[Alister Chapman]

Don't forget you also have the FL color matrix in the Picture Profiles to help control the excess green from the florries.

[Leonard Levy]

Whatever lights you get I would suggest getting some light (1/8 & 1/4) Plus green gels and then experimenting with a decent monitor for one day to see if you can get a color balance on your lights that matches well enough with the existing flourescents.
Sometimes you are fine just overwhelming them with your own lights - (even tungstun or tungstun with say 1/2 blue) and letting the backgrounds go with the flourescents. It sounds like for stand ups you may only have one key light so getting a match is probably a better idea. As always its really valuable top have a decent monitor with you. Flourescenets can be all over the map especially if they are old.

Also again especially if they are old watch out for rolling shutter issues which may be seen as a slow moving yellowish bar across the screen. I didn't notice this for a awhile the first time I encountered it.

[Lucky Haskins]

>Don't forget you also have the FL color matrix in the Picture Profiles to help control the excess green from the florries.<

Could you elaborate on the FL color matrix??? I'm looking at the PP menu overview in the EX3 Field Guide and don't see FL in the Matrix settings.

[Jason Davenport]

Just always remember, what lights are the "most dominate" in a setting. And match all other light you bring in, to match them. Hospital- all greenish, so add Plus green to your lights. Then white balance, now your all lights will come out white. If you still have green on faces when you move in the lights and your Flows in ceiling are still a acceptable white, then uses less green on your key lights. If you white balance first in room then try to add color to lights it's a lot harder. If you have no lights to add and white balance and still have a little green try tricking the white balance by putting a 1/8 green gel over lens then WB again. The camera will try to remove more of the green. Gel swatch books are best for this.
This is basically what warm/flow cards are doing.-you can just do it for free with gels.-

Use your "eye" to judge the color of dominate light, is it warm, greenish, blueish etc. for gel selection. Only go into matrix if you know what your doing and have a accurate color chart to use.

[Alister Chapman]

The FL color matrix can be set by anyone and does not require any expertise or color charts. It's simply a matter of turning it on and it is very effective. It also has a fairly minimal impact on tungsten and daylight sources.

Go into the picture profiles, choose a profile then scroll down to the matrix settings. Turn the matrix on, then scroll down to Matrix. There you will find the option to choose between 4 preset matrices. Standard, HiSat, FL Light and Cinema. Simply select FL Light. You can find more details about white balance and the matrix in my video guide on youtube.

YouTube - XDCAM EX Color Matrix Setup and How To instructional video

It's easy to select the FL Light matrix, it is designed for shooting under flourescent lights and will give a more natural color response than simply tricking the white balance with gels etc. White balancing with gels will effect the white balance of the picture, skewing whites away from white, If you are warming or cooling a picture this can be effective, but removing green adds purple into whites which looks wrong. Using the matrix leaves whites largely alone but instead takes the overall green cast out of mid tones including skin tones etc.

There is far too much emphasis on color charts and 100% one to one, set it up with a scope settings. Very often a 100% accurate one to one response won't look right as the video gamut is smaller and lopsided compared to that of the human eye so a small amount of skewing of the color gamut can often help produce a picture that visually looks more natural. One of the very best ways to set up a camera is to use a high quality color photograph of a known scene. Shoot the photograph and look at the picture on a monitor and adjust until it looks right. This will give a more natural looking image than aligning with charts and scopes and is a technique that has been used since the very beginnings of color television. I have a scene that contains vibrant colored cars, green fields and trees, buildings and blue sky. I have a dozen large copies of this picture and use it whenever I am making camera adjustments to make sure my pictures still look natural.

[Dave Morrison]

Alister, please correct me if I'm wrong (always willing to learn new stuff in the video world!), but I was always taught that color corrections made for FL lighting was slightly different from the way you described it. If, for example, you look at a spectragram readout of a FL lighrt source, what you will see is a severe deficiency in red spectra (or magenta, more specifically). It's not that the FL source is pouring out an abundance of green light, but that it is highly deficient in the red area and we are adding that back either via filters (CC30M, for example) or via electronically skewing the response of the imaging chip/system. Or am I completely off here?

[Alister Chapman]

It doesn't make much difference whether you are dealing with a spike in the spectrum or a hole, the effect is very similar. My understanding is that fluorescent lights have a strong very narrow peak at a specific green wavelength. My experience is that if you white balance under FL lights you will get white whites, however skin tones still take on a greenish sickly look. If you use a gel to offset your white balance, while you might help the skin tones, now your whites will be a little off. If it was as easy as simply white balancing under the florries then there would be no need for gels, tricked white balances or FL matrix settings. The green spike is very narrow, which is why the overall white balance is not affected by it. Our eyes/brian are very sensitive to skin tones changes however which is why we pick up on the extra green on faces etc.

White balance operates by changing the gain of the sensors, thus changing the gain across the entire red, green and blue spectrums. The matrix works differently. It changes the both the hue and mix of narrower chunks of the spectrum, without affecting the white balance. Thus a dedicated FL matrix can be used to effectively filter out the green spike without upsetting the broader white balance.

[Leonard Levy]

There are many ways to skin this cat if you don't mind the analogy. I've never used the FL matrixes but its certainly worth looking at. What I often do, in fact whether under floros or not is use the magenta /green hue adjustment in the PP menus. I always do this with a monitor however. Some caneras simply tend to balance a bit green and always need a little correction.

Jason's suggestions are good esp about staying out of the matrix, however that really applies to the individual matrix settings. The overall Fl setting is probably safe but it may tend to give you faces that are too magenta .

The main thing is during Prepro or on your first day at least have a good monitor with you to figure out what looks like a good way to proceed.

[Alister Chapman]

The electronic white balance circuits on most cameras are remarkably simple. The camera simply looks at the chroma level and adjusts the gain of the R G and B circuits until the chroma level is minimized, hopefully ending up at near 0 for whites and greys In a perfect world, white would be a picture with whites and greys that are all luma and no chroma. The camera doesn't actually know or care what color the output is, all it cares about is minimizing the chroma level. If you watch a waveform monitor while doing a white balance you should see the chroma level in your whites or greys drop. You have to be carefull when dealing with colour tints or colour casts as in most cases the white balance if done correctly it will be accurate. Colour casts or tints tend to be a result of incorrect color balance (possibly deliberate) due to whites/ grey cards that are not truly white, the card being angled towards the wrong light source, over reflective white cards etc. The beauty of the matrix is that you can warm, cool or otherwise adjust the colours within the image without changing white. As an example if you use warming cards to warm a picture your whites will now have a slight orange or red tint, this may be desirable. If you use the matrix to add a little more red or remove a little blue whites will still be white but the colors in the picture will be changed.

You can't break or damage the camera by playing with the matrix settings. Sure you could end up with a hideous looking image, but that will be visible in the VF or better still on a monitor. Users should not be afraid of going in and trying these settings for themselves. The best way to learn about how they behave is to use them. I do get a little tired of people telling novices to stay out of the menus. We were all novices once, the only way to learn is to go in there and make use of the tools provided to us by the manufacturers. I wouldn't recommend doing it on a big paying job, but sit down in the office or at home with the camera and play with the picture profiles.

[Vincent Oliver]

Originally Posted by Alister Chapman

...... We were all novices once, the only way to learn is to go in there and make use of the tools provided to us by the manufacturers. I wouldn't recommend doing it on a big paying job, but sit down in the office or at home with the camera and play with the picture profiles.

You wouldn't expect a concert pianist to get up on the platform and start playing a new concerto. He/She would have spent hours/days/weeks rehearsing the work, experimenting with every nuance of the music before finally combining it with the full orchestra. The pianist would not learn the finer points of the music by just reading the notes, it’s actually playing the music that counts.

The same holds true for using a video camera such as the EX3/EX1. Experimenting with the various settings will help you to appreciate what the camera can do for you. Once you have arrived at a satisfactory formula then you can use the settings within your digital workflow. As Alister says. “You can't break or damage the camera by playing with the matrix settings.” , but if the picture does look hideous then you can always reset the camera back to its default setup. The real value comes from having tried out the various permutations for yourself.

Here ends the lesson.

Ps. Does anyone know where the On/Off switch is :-)

[Leonard Levy]

I am all for experimenting with matrixes but beware that like with knee settings, you can make one shot look great while others look weird. So if you do make changes check them in a variety of situations. White balancing with a touch of green has been used by many shooters for years and is unlikely to ruin your color balance in a noticeable way. But by all mean experiment and find what you like.