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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

80 A, B or C filter?

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Evolution

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I am shooting in an office with overhead fluorescent lights that may have to be on, tungsten lights on talent, either tungsten or fluorescent light on green screen, and a teleprompter.

I have heard 80 A, B & C all recommended for on the camera. What would work best in the scenario ( above mentioned lights, green screen, and prompted)?

Also, what is the best place to buy and brand to buy ( I have red rock matte, but can't fit with prompted, do I need one to fit the lens?).... Thank you

I need to get it quick...by Thursday...
 
Different tech, different filter

Different tech, different filter

Be aware that the 80 series filters were designed for a specific MIRED shift endemic to using daylight balanced film emulsions with tungsten sources. Digital sensors, particularly CMOS based 5000 Kelvin native like the Mysterium have a somewhat different profile. I recently started using a 1/4 CTB filter from Schneider that I believe, in most cases, gives me all the CT shift I need to keep the blue channel happy with less light loss. YMMV.

Cheers - Blair
 
Where would you recommend getting one?
 
You could always gel your tungsten lights, not the camera. In fact, those flouries might be closer to daylight than you might think, so using a CTB filter on your camera will make the ambient light very blue indeed.
 
The 80 series solution was suggested in your other thread assuming you were in a studio with green screen and tungsten lights.

This is a different situation entirely and the 80 series probably won't do much good here.

If you want consistent color, then you need to find out what kind of fluoros you are dealing with.

Cool whites? Warm whites? Then gel your tungsten lights to match or...

In this particular case you may be better off using HMI's and kinos. Put the locations tubes in your kinos for a perfect match.

Hope this helps.
 
The new Schneider CTB (color temperature blue) filter in glass is available in 1/4, 1/2 and full from FilmTools in Burbank - tell Stan that Blair sent you. Be aware these filters are in high demand so they might be on back order. IF you can only afford one I recommend the 1/4 as it only costs you about a half a stop in light and should give the blue channel enough juice to hold up nicely during the de-mosaicing step.

The 1/2 would make more sense for a well lit green screen shoot under tungsten where you could afford to give away a full stop. It would yield the lowest noise levels which will make the keying and matting process that much cleaner.

Of course if you have some HMIs or daylight bulbed Kinos or LEDs...
 
Fl-d

Fl-d

You might do some tests with a FL-D.

Lee makes a greenish gel that goes with their FL-D type filter to let you use tungsten lights, look at your Lee gel book for the filter numbers. You need to use both the special filter on the lens (magenta), and the gels on the lights (greenish) to get neutral results, the two filters mate and mix with florescent lights.

FL-D is a special magenta filter that works with florescent lights to restore the Red and balance the green vs. the red/blue. There are some similar filters for florescent lights of different type i.e. cool white, warm white, daylight type etc.

Most florescent lights have enough blue, but not enough red and too much green, so a magenta filter is better than a blue filter that would cut the red light mode. Florescent lamps have too much yellow, so a glass "(Red) Enhancing" filter that cuts yellow may also help along with the FL-D.

Set the camera to daylight balance.

If you do not use the magenta filter on the camera and the greenish gels on the lights you can get off color green shadows that happen with mixed color light. Daylight windows also need gel to match, but not the same one used on the tungsten lights.

See these links,

http://www.bhphotovideo.com/c/produ...FLSET_Daylight_Fluorescent_FLD_Polyester.html

http://www.leefilters.com/camera/products/finder/ref:C4762A0744EC20/

When the light going to the sensor is off color, the number of bits is reduced so you no longer get 12bits for all three primary colors, if the balance of the light is way off you might get less than 10bits of dynamic range, so it is best to filter the light and or the camera to get as close as you can to the natural balance of the sensor for equal clipping of the primary colors, in the case of the sensor in the REDONE about daylight K values.
 
In the mix

In the mix

Dylan makes a good point about shooting mixed sources, especially when one of them is floros with their characteristic green spike. There are some much nicer florescents around but unless you are extremely lucky chances are you will have to deal with the el cheapos which have the CRI characteristics of a schizophrenic.

If you can get your proper tungsten sources on most of the critical skin tones and if a slightly sickly looking background suits the material you'll be fine. If the piece calls for a warm and "sweet" looking color palette beyond the foreground subjects then you better start campaigning for a bigger grip package and time to put up a lot of lights...

If you are near the site or can get someone to check for you, you should read the label on the tubes to see what you have. IF practical you could shoot a proper white card (most papers have bleaches and brightners that shift blue) at 3200, 5000 and 5600 Kelvin and open them up in Photoshop to get a read on the CT.

There are also some great minus green gels. Even if its impractical to gel every florescent in the place you might be able to gel a few that are in critical spots near talent to minimize odd color reads.

Cheers- Blair
 
I can recommend as a simple ballpark colour meter, using a digital camera ( I use a nikon d200) to shoot a grey card under the ambient lighting while your doing your recce. when you bring the raw file into photoshop, the raw import dialogue gives you a pretty good idea of of the colour temp of the ambient lights , flouros in this case. I'd go with then gelling your lights to match as close as possible to the ambient ( if thats the look your after ) and maybe correct on camera if it is all still less than 4300K using Blair's suggestion.
 
Thank you everyone for all of the information.

Unfortunately this is a short notice job, that the client keeps changing the parameters on, I should have expected this for the first shoot with the Red.

Unless there is a filter (such as the CTB 1/4 ? recommended by someone) that will not hurt (and have no effect), and at best possibly help (with the mix of tungsten and the overhead fluorescent, I don't know if the filter can make things worse). I may just have to set the white balance to tungsten, light the heck out of the green screen, do a nice light on the talent (typical 3 light set-up), and film.
 
Liam,

Fine without any filters on the camera?
 
If you have time to get the 1/4 CTB I would still suggest it as it is mild enough to do more good than potential harm. Don't know if you will be able to get any of the specialized gels Dan suggested or what the stop loss would be of using complimentary on lens and on lamp filtration, not to mention the time and manpower to implement.

Liam makes a good point about even lighting on the green screen. I suggest using the false color (Predator mode) meter on the RedOne to fine tune your lighting. I am a proponent of getting at least the bright green level (18% gray and roughly 45 IRE) with a maximum of two colors reading in false color on the screen. I actually spin the monitor around so the gaffer can eyeball it while adjusting the lights - if he has a dimmer pack or even just a squeeze box it can really speed things up on location (not to mention flooding, panning, etc).

Try to avoid geometry that bounces a lot of green back onto the talent, a little white or even slightly blue rim is your friend, underlit green has the potential to be a noise issue so give it some level.

Best of luck - Blair
 
Blair S. Paulsen said:
I actually spin the monitor around so the gaffer can eyeball it while adjusting the lights - if he has a dimmer pack or even just a squeeze box it can really speed things up on location (not to mention flooding, panning, etc).
Click to expand...

I'd caution against using a dimmer otherwise known as a hand squeezer or variac (squeeze box) on a tungsten source, your color temperature changes quite dramatically when lowering the voltage thus creating an odd white balance on your target subject.
 
Evolution said:
Liam,

Fine without any filters on the camera?
Click to expand...

Yes. An even exposure is the most important thing. Try and get rid of as many wrinkles in the cloth, so there are no shadows and check your histogram to see that you are getting a good exposure. But above all, make sure you light the talent as best you can.

Alexander Nikishin said:
I'd caution against using a dimmer otherwise known as a hand squeezer or variac (squeeze box) on a tungsten source, your color temperature changes quite dramatically when lowering the voltage thus creating an odd white balance on your target subject.
Click to expand...

I agree, dimming tungsten more than 10% makes them even warmer. Just move them back if they're too hot.
 
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