How does false color work on monitor?

J

Jonathan_P

Well-known member
I miss the zebras on my XH-A1 and would like some better way of judging exposure on my GH2 than the flashing thing it does at 100 IRE. I'm looking at a field monitor that does false color but I was wondering how it works. In particular, can you adjust the thresholds for the different colors? For example, I'd like to set a particular color at 70 IRE which is the threshold I liked to use for caucasian flesh tones. Thanks!
 
Ok, just answered my own question, at least partially. Downloaded the manual for the Marshall 5" monitor and it shows a chart of the colors associated with each IRE threshold. I was surprised to find that they assigned an IRE of 56-57 for flesh tones though...
 
On the TV Logic VFM-056 WP you can adjust the thresholds, since it has that color bar stripe on the screen and it changes dynamically as you adjust, instead as a cardboard stripe that you stick on the housing.

At the beginning it´s a bit strange, especially when you came from zebras, but after you get used to it, you never look back.

I try to keep my skin tones in the neighborhood of 70.

Frank
 
Postmaster said:
On the TV Logic VFM-056 WP you can adjust the thresholds, since it has that color bar stripe on the screen and it changes dynamically as you adjust[...]
Frank
Click to expand...

I'd love to be able to adjust the thresholds. I wonder if you can do that with the SmallHD. What do you mean by "that color stripe on the screen"?

I'd also be curious to know what IRE other people use for flesh tones. I also have always used 70...
 
I mean on most monitors I saw, like Marshall they come with a colored cardboard strip that you stick on the monitor for reference.

Marschall_b_Vorlage.gif


On the TV Logic it appearers on the screen when you set it to false color, like the historgram or the vectorscope.

B_0311_Displays_11.jpg


Great thing, if you change the threshold this "false-color-bar" changes dynamical so you get a proper reading.

Frank
 
Postmaster said:
On the TV Logic it appearers on the screen when you set it to false color, like the historgram or the vectorscope.
Great thing, if you change the threshold this "false-color-bar" changes dynamical so you get a proper reading.
Frank
Click to expand...
Too cool.

I just looked up info on the SmallHD false color implementation and it's also fixed, like the Marshall. Moreover, it uses a single (although graduated) color from IRE 58-97. Not liking that much in theory but maybe it works better in hand.
 
Jonathan_P said:
I was surprised to find that they assigned an IRE of 56-57 for flesh tones though...
Click to expand...
Yeah, I only recently bought the Marshall 5 inch and the whole false colour thing is a bit hard to adjust to... The flesh tone does sound a little low, but for me 70% is best for the highlights on one's face (forehead, cheek bones etc), so I guess 56/57% might be a better average... And its always good to under expose a little... Still, I think the false colours would confuse me too much!
 
Do not trust the video out. (At least on the GH2)

Do not trust the video out. (At least on the GH2)

While it is nice to use the false color option provided on monitors, I would strongly recommend against using it as a hard and fast rule for determining exposure. (At least for the GH2 anyway.) It is a good tool to use for a rough guestimate of where things fall, but the video out of the GH2 preview is NOT what is being recorded. What is being recorded, is much closer to what the camera displays when you press record. (You'll see that gamma shift when you hit record.) So if you are using false color on the monitor for an absolute reference, then you will be mistaken as the recorded image is different. (Unless you constantly hit record to check where things fall while you light...)

The Best way to determine exposure IMO is to use a meter. But that is another discussion ...

The next best way, is to use the built in meter in the camera. Turn it to spot (just the small cross hairs) and then the small bar graph at the bottom will let you know where things fall. Caucasian skin should fall in Zone 6 (+1 on the bar graph).
 
Jonathan_P said:
Ok, just answered my own question, at least partially. Downloaded the manual for the Marshall 5" monitor and it shows a chart of the colors associated with each IRE threshold. I was surprised to find that they assigned an IRE of 56-57 for flesh tones though...
Click to expand...

Thats where skin tone should be. Slightly above middle grey. I just gave a big speech about this at the AF100 Boot camp with Barry Green. People complain about skintones "clipping" on certain cameras, because they are over exposing, but dont know it. I dont know where the skin should be at 70IRE idea came from, i used to do it when i first started thinking it was the proper way, but then i learned better. The brightest highlights on the skin, the forehead, and edge light on the cheek, should be at around 70. For some reason a lot of folks over expose skin tones and keep the fill side of th face in the upper 60's and 70's... Truth is, if your base skin tone is in the 70's your high lights will be in the 80's and thats the territory where the knee circuit starts to kick in and you get colored blobs of unnatural "clipping".

Also, take your favorite Bluray, run it through the HDMI on your monitor, and see where the skin tones fall. do it across your favorte scenes in your favorite films. you will see where skin should be.
 
Ebay- you can score some great deals there. The 758D, 758DR, 758Cine are all great meters. (I prefer the 758Cine).

If you are not going to use it for photography with a flash, then you can get some good deals on meters form photography stores in Japan selling them. I was able to score the 758C for about 1/2 price. The only catch is that flash units are region based. So if I ever wanted to use my meter with a flash, I would have to be using Japanese flash units. (Not a big deal, as I do not use flash ...)

Also, check your local photography store- I was able to buy my first analogue meter for about $30, and it worked great. But it was only incident. I find spot metering to be VERY helpful, and I use it the majority of the time on set.
 
Ryan E. Walters said:
While it is nice to use the false color option provided on monitors, I would strongly recommend against using it as a hard and fast rule for determining exposure. (At least for the GH2 anyway.) It is a good tool to use for a rough guestimate of where things fall, but the video out of the GH2 preview is NOT what is being recorded. What is being recorded, is much closer to what the camera displays when you press record. (You'll see that gamma shift when you hit record.) So if you are using false color on the monitor for an absolute reference, then you will be mistaken as the recorded image is different. (Unless you constantly hit record to check where things fall while you light...)
Click to expand...
Good point. The GH2 is making me work hard in a bunch of ways and this is one of them. I wish there were a way to trick the camera into showing me how it will look when recording without actually recording...

Ryan E. Walters said:
The next best way, is to use the built in meter in the camera. Turn it to spot (just the small cross hairs) and then the small bar graph at the bottom will let you know where things fall. Caucasian skin should fall in Zone 6 (+1 on the bar graph).
Click to expand...
I've been using the little bar graph as a guide but I don't think I was using spot metering because it had a resizeable box instead of just the crosshairs. I made the box as small as possible so it just covered part of the face but I suspect it might still be adjusting for light outside the little box because the face looks slightly overexposed even with the little bar graph at 0. I'll have to make sure I'm using spot metering when I test this later today...
 
TimurCivan said:
Thats where skin tone should be. Slightly above middle grey. I just gave a big speech about this at the AF100 Boot camp with Barry Green. People complain about skintones "clipping" on certain cameras, because they are over exposing, but dont know it. I dont know where the skin should be at 70IRE idea came from, i used to do it when i first started thinking it was the proper way, but then i learned better. The brightest highlights on the skin, the forehead, and edge light on the cheek, should be at around 70. For some reason a lot of folks over expose skin tones and keep the fill side of th face in the upper 60's and 70's... Truth is, if your base skin tone is in the 70's your high lights will be in the 80's and thats the territory where the knee circuit starts to kick in and you get colored blobs of unnatural "clipping".
Click to expand...
I realize now that what you suggest is essentially what I've been doing. ChrisDTV made the same point above. I would set the zebras on my XHA1 at 70 IRE and then closed down the aperture to where they were only visible on the brightest highlights. Since I wasn't metering the rest of the face, I never really thought about levels for the rest of the face.

TimurCivan said:
Also, take your favorite Bluray, run it through the HDMI on your monitor, and see where the skin tones fall. do it across your favorte scenes in your favorite films. you will see where skin should be.
Click to expand...
Cool idea!
 
Jonathan_P said:
Good point. The GH2 is making me work hard in a bunch of ways and this is one of them. I wish there were a way to trick the camera into showing me how it will look when recording without actually recording...


I've been using the little bar graph as a guide but I don't think I was using spot metering because it had a resizeable box instead of just the crosshairs. I made the box as small as possible so it just covered part of the face but I suspect it might still be adjusting for light outside the little box because the face looks slightly overexposed even with the little bar graph at 0. I'll have to make sure I'm using spot metering when I test this later today...
Click to expand...

Yeah, you definately have to change the mode to spot metering - so that only the point of the crosshairs is being read. It is one of the metering options in the camera.
 
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