Saturated Color Highlights

[nyvz]

Anyone find any solutions to the issue the FS100 has with highly saturated primary colored highlights? I was just shooting a performance at fashion week that had all blue lights and it came up and I couldn't get rid of it with any tweaking. I tried changing color depth and color level and nothing could prevent the brightest blue lights from going cyan and then white in a very harsh way. I've had this issue in the past with primary red lights as well, and I've seen this several times on non-Slog F3 footage as well. I always assumed it was an issue with the way Sony crops off the top couple of stops of highlight detail on the FS100 and F3 and reserves them for use only on the F3 with Slog. Has anyone seen this with colors besides red and blue or is it limited to just those colors? Anyone find any solutions? It does not come up often, but when it does its pretty nasty.

 

[cuervo]

This is just a wild suggestion, since I haven't tried this myself...but I have noticed the problem you're describing. I wonder if a Chromatic Aberration Correction tool will reduce this.

 

[nyvz]

I can't imagine how it would since it is not an optical chromatic aberration, which is what those tools are intended to correct. I may do some further in-depth tests to better understand the issue. I would think some over-exposed ramps or over-under chip chart exposures would give us a lot of information on the issue. In my casual testing, it seems this issue may be impossible to avoid besides avoiding bright primary colors.

 

[SergeSmArt]

Anyone find any solutions to the issue the FS100 has with highly saturated primary colored highlights? I was just shooting a performance at fashion week that had all blue lights and it came up and I couldn't get rid of it with any tweaking. I tried changing color depth and color level and nothing could prevent the brightest blue lights from going cyan and then white in a very harsh way. I've had this issue in the past with primary red lights as well, and I've seen this several times on non-Slog F3 footage as well. I always assumed it was an issue with the way Sony crops off the top couple of stops of highlight detail on the FS100 and F3 and reserves them for use only on the F3 with Slog. Has anyone seen this with colors besides red and blue or is it limited to just those colors? Anyone find any solutions? It does not come up often, but when it does its pretty nasty.

From the begining I try to use HD filters and "FLAT" setup .. and this hepl me a lot:

This "SUIPERFLAT" - from Canon 5D2 :

and I found something similar to Sony FS-100:

Setup I use is: ND-fillter 0.9 and (1.5 with Canon lenses),
PP5, Black level + 10 , Gamma: Cinematon -1, Knee poit 90% Slope +2, Color Mode - Cinematon_2, level 8, Color level -4, Color Depth: all Colors+5, Detail -0


Here the samples:

I hope it will help ...

 

[MattDavis]

Anyone find any solutions to the issue the FS100 has with highly saturated primary colored highlights?

A couple of pointers:

Firstly 'nature of the beast' - We're recording in 4:2:0 which means (not exactly) that colour is quarter the resolution of brightness. The more intense the colour, the more pronounced the blockiness.

Secondly, the tendency of single-chip cameras that don't cost as much as a car to clip strong chrominance faster than the luminance (hey, my EX1 does it, every camera I've owned does it). People want colourful pictures, so chrominance is wound up by manufacturers. With stage lighting, the colour intensity levels wrap the needle round the end stop. The encoder can't cope, and just cuts off everything over a certain level (hence the posterisation, the nasty duocolour halos around highlights, and so on).

The solution, as SergeSmArt points out, is to try and wind down the colour amplification in your picture profile. However, that means every single shot will need grading to put back the chroma in less intensely lit shots. Note: many picture profiles will suffer the same fate if they're not specifically about shooting under stage lighting.

We're all still playing with Picture Profiles, and Picture Profiles seem to follow the same principles as spaghetti sauce. You don't have just one, you do need 'extra chunky' stage lighting sauce too.

 

[nyvz]

A couple of pointers:

Firstly 'nature of the beast' - We're recording in 4:2:0 which means (not exactly) that colour is quarter the resolution of brightness. The more intense the colour, the more pronounced the blockiness.

Secondly, the tendency of single-chip cameras that don't cost as much as a car to clip strong chrominance faster than the luminance (hey, my EX1 does it, every camera I've owned does it). People want colourful pictures, so chrominance is wound up by manufacturers. With stage lighting, the colour intensity levels wrap the needle round the end stop. The encoder can't cope, and just cuts off everything over a certain level (hence the posterisation, the nasty duocolour halos around highlights, and so on).

The solution, as SergeSmArt points out, is to try and wind down the colour amplification in your picture profile. However, that means every single shot will need grading to put back the chroma in less intensely lit shots. Note: many picture profiles will suffer the same fate if they're not specifically about shooting under stage lighting.

We're all still playing with Picture Profiles, and Picture Profiles seem to follow the same principles as spaghetti sauce. You don't have just one, you do need 'extra chunky' stage lighting sauce too.

I am quite certain this has nothing to do with 4:2:0 color sampling. The EX1 does not do what I am talking about. I said I tried rolling the color saturation all the way up and all the way down as well as the blue and cyan color depth and it had no effect on the issue. It seems like there is an issue with these cprimary color highlights that may start before entering the picture profile system or the encoder. I guess I will keep trying different settings.

 

[Stu Siegal]

If you search the AF100 forum, you'll find plenty of discussion of clipped highlights. Barry Green had a very good post early this year describing why it happens with regard to reds clipping to yellow before going white on the AF. I'm guessing you're experiencing a similar issue, and the short answer is unfortunately, it is the nature of the beast for cameras in this space. The quick fixes for the AF is to desaturate the chroma so that the rolloff is more natural, and when shooting in controlled environments, watch exposure, though I completely get that at a fashion show, simply not possible.

 

[nyvz]

If you search the AF100 forum, you'll find plenty of discussion of clipped highlights. Barry Green had a very good post early this year describing why it happens with regard to reds clipping to yellow before going white on the AF. I'm guessing you're experiencing a similar issue, and the short answer is unfortunately, it is the nature of the beast for cameras in this space. The quick fixes for the AF is to desaturate the chroma so that the rolloff is more natural, and when shooting in controlled environments, watch exposure, though I completely get that at a fashion show, simply not possible.

Yeah I've posted a lot about that issue on the AF100 myself, but this is a fairly different issue. In the AF100, the yellow highlight shift happens no matter what in all settings and in all situations where anything is blowing out, and that camera blows out pretty easily. The issue I'm talking about on the FS100 and F3 does not show up unless you happen to be shooting in very high contrast situations containing very bright primary color lights, such as in a nightclub. I agree it is in both cases probably related to a poor implementation in the camera. When it shows up, though, you will know it because it looks quite posterized and even blue turns into a light cyan in an instant.

 

[Stu Siegal]

nyvz, did you switch from the AF to the FS, or do you own both?

 

[nyvz]

nyvz, did you switch from the AF to the FS, or do you own both?

Two companies I have been shooting for have had me shoot on their AF100s. I did some tests with it when they got it in January and was not happy at all with the gamma curves and options or the lack of expanded focus. I tried every scene file option and played with a chart and wfm/scope and couldn't get highlights or color that looked even as good as my 7D, which itself leaves a bit to be desired on those fronts in my opinion. I decided to buy the FS100 after playing around with it at a couple sony events, and I am extremely happy with it, the cinematone1 gamma curve looks about as good as I could ever hope for an 8bit video camera, and the level of detail and lack of noise in nearly no light is absolutely incredible.

I just shot some stuff at fashion week and had to go to 27db gain on an f2.8 24-70 on some shots and it came out quite good. I've had clients complain about the noise on the AF100 at iso800.

Now if only there was a way around this darn issue with the way the FS100 renders primary color highlights...

 

[nyvz]

BTW, here is one of the videos I did with the FS100 and sigma 24-70 f2.8. I mostly cut around the primary color highlight issue shots but you can see it a bit in the wide shot of people dancing in hard blue light. There are a few videos up there I shot on my FS100 for that company in the past couple days.

http://www.youtube.com/watch?v=ugq9BQcnqMo