want to light a room in red-- does the red channel clip easy? -

[nycineaste]

I want to shoot a scene in completely red ("fire engine" red) light, but my (very limited) understanding is that there is something about the red channel not having as much information as the other channels so theres a danger of clipping in the image?

In order of preference the choices are to get this thru white balance (find the right green colored card), a gel (a tough one- I dont want hard light and once the light goes through the gel and the softbox theres not much power left , no? and Im lighting a large living room- clearly multiple lights if I go this route)... Last choice is to do it in post, but the red channel info is still limited in info no?

any technical data regarding the red channel (on the dvx100a and in digital video in general, right?) and its propensity for clipping much appreciated

I'm learning that technical skill gives you the power to express your ideas. Just wanted to express appreciation for this forum. Thanks in advance!

 

[David Jimerson]

There's no reason not to do it in-camera. My first choice would be to gel all the lights red. Keep in mind how red light will affect the appearance of different-colored objects, though; blues and greens will appear black, etc, because they have no red to reflect back and will absorb (almost) all of the light. The closer an object is to red, the more it will appear white, because it'll actually be really red in a sea of red, and red becomes the de facto white (whew).

Play with the white balance, but start with it being "neutral" or balanced to the house lights and go from there.

Information is all about exposure, so be sure to adhere to proper exposure. You can monitor any clipping using a waveform, or zebras.

And keep in mind -- post is an option for putting a final sheen on the look if you can't quite achieve it in-camera. So, experiment. See what works.

I'm learning that technical skill gives you the power to express your ideas.

^^^^^^^^^^^

All the technical skills are there to support the art.

 

[j1clark@ucsd.edu]

There's no reason not to do it in-camera. My first choice would be to gel all the lights red. Keep in mind how red light will affect the appearance of different-colored objects, though; blues and greens will appear black, etc, because they have no red to reflect back and will absorb (almost) all of the light. The closer an object is to red, the more it will appear white, because it'll actually be really red in a sea of red, and red becomes the de facto white (whew).

Play with the white balance, but start with it being "neutral" or balanced to the house lights and go from there.

Information is all about exposure, so be sure to adhere to proper exposure. You can monitor any clipping using a waveform, or zebras.



^^^^^^^^^^^

All the technical skills are there to support the art.

Even with Film film, red lit scenes seemed frequently 'blurry'. It may have to do with lenses being 'wide open' or there abouts, and that the 'red' focus point is slightly shifted from the 'focal' plane. Stopping down corrects for that slight shift.

 

[Bruce Watson]

There's no reason not to do it in-camera. My first choice would be to gel all the lights red.

I beg to differ. Which is sort of like begging to get smacked by a 2x4 in this case considering Mr. Jimerson's reputation which is far, far greater than mine will ever be.

The reason I wouldn't do it all in camera is to avoid starving the green and blue channels during capture. If you starve the green and/or blue channels, they'll generate noise. In this case, especially the blue channel.

It might be better to only go part of the way at capture time, but to light so that none of the camera channels are starved for light. Then in post selectively lower the green / blue channels to get the amount of red you want in the overall picture without the noise in the green / blue channels.

I'd rather fight color in post than noise any day. But maybe that's just me. IDK.

 

[Barry_Green]

I want to shoot a scene in completely red ("fire engine" red) light, but my (very limited) understanding is that there is something about the red channel not having as much information as the other channels so theres a danger of clipping in the image?

Shooting under 100% red light will introduce two complications, when using a DVX100: low resolution video, and exposure issues.

First, low resolution: the DVX100 records 4:1:1 video (in NTSC, it's 4:2:0 in PAL). In both cases, what that means is that the red channel sees only 1/4 the total image resolution (or, more appropriately, when recorded the system throws 3/4 of the red and blue channel's information away). The net result is that you'll have 180x480 resolution in NTSC, or 360x240 res in PAL. That means chunky, blocky video.

Second, exposure: there's not really any problem with clipping, the red channel has as much range as the green or blue do, the CCDs are identical -- it's just that one has a red filter over it, one has a green filter, and one has a blue filter. BUT: if you're relying on the zebras to tell you what's exposed properly, you need to reorient your thinking. Zebras (and waveform monitors) report brightness in IRE figures, which is a scale from 0 (pitch black) to 109 (clipped white). HOWEVER, that number is calculated from all three color channels together, using a formula that uses 30% of the red channel, 59% of the green channel, and 11% of the blue channel. But you won't have green or blue in your shot, so that means that when the red channel is at 100% saturation, the zebras will only be reading 30(!) The formula is 30% of 100 (R), 59% of 0 (G) and 11% of 0 (B); add that up and you get 30. So when exposing under solid red light, you never want your zebras to go above 30; any higher than 30 and your footage will be clipping.

 

[David Jimerson]

I beg to differ. Which is sort of like begging to get smacked by a 2x4 in this case considering Mr. Jimerson's reputation which is far, far greater than mine will ever be.

The reason I wouldn't do it all in camera is to avoid starving the green and blue channels during capture. If you starve the green and/or blue channels, they'll generate noise. In this case, especially the blue channel.

It might be better to only go part of the way at capture time, but to light so that none of the camera channels are starved for light. Then in post selectively lower the green / blue channels to get the amount of red you want in the overall picture without the noise in the green / blue channels.

I'd rather fight color in post than noise any day. But maybe that's just me. IDK.

Well, I don't really disagree about not doing it ALL in camera; I did suggest that post grading is for that which can't be done in camera effectively, and to experiment to see how well it works so that you'll know what you can do in camera, and what you'll need to enhance in post. That way, you can plan your shoot and your edit accordingly. I'm sure we're certainly on the same page that the day of your actual shoot is not the day to figure it all out.

And, of course, much has to do with the exact thing he's trying to do, which only he really knows.

(I must admit I missed originally that he's shooting on the DVX100, and I would have tempered my answer considerably more if I hadn't. Reds and the DVX are always kind of . . . fun. )

 

[Josh Bass]

Something I didn't see in here: I read once that it's a better idea to, instead of simply gelling all your lights red, you gel them red, BUT, poke holes in the red gel to let some of the 3200k (presumably) light through as well, so you're not just just blasting pure red at everything. So a bunch of holes/slits whatever, like you're making a poor man's cucaloris with blackwrap but with gel instead. I would assume you'd have to put a piece of diffusion in front of or behind the red gel when you do this as well, so you don't get very obvious "splotches" of "white" light. The diffusion will sort of even everything out. Have not tried this myself.

 

[Michael Carter]

When I think of how much control you have using Tint or Tritone (AE) in post... I'd at least do some basic testing of all 3 scenarios: in-camera, shoot it warm on set and grade, and just full-on re-coloring in post. (You could also just use a red wratten gel filter on the lens). It's not just what's technically the best exposure, it's what gives you the look you're envisioning.

(I should change my sig to say "test, test, test"...)

 

[nycineaste]

Thats my plan, Michael- Im gonna wrap my head around all this info and try a few different things.

Im not big on the idea of doing it all in post (not my first choice), but I will if I have to. Sony Vegas has a "channel blend" effect that lets you swap the information in the channels. It may be something I use in combination with in-camera techniques. I'll keep you guys posted and post my test footage.

Thanks a million for all the info and ideas!

 

[Rob Moore]

Thats my plan, Michael- Im gonna wrap my head around all this info and try a few different things.

Im not big on the idea of doing it all in post (not my first choice), but I will if I have to. Sony Vegas has a "channel blend" effect that lets you swap the information in the channels. It may be something I use in combination with in-camera techniques. I'll keep you guys posted and post my test footage.

Thanks a million for all the info and ideas!

You should watch 'only God forgives' for a great example of what you're thinking.
Also can you post some still
S of your results.

 

[nycineaste]

I'm always on the lookout for movies with "expressionistic" lighting to learn from, and I was avoiding that flick cause it got kinda mixed reviews. Definitely will check it out now.

Thanks!

 

[Rob Moore]

I'm always on the lookout for movies with "expressionistic" lighting to learn from, and I was avoiding that flick cause it got kinda mixed reviews. Definitely will check it out now.

Thanks!

Well, honestly it's a pretty stupid movie but I would say it's bordering on masterpiece of lighting and cinematography.

How about those stills.