How do you keep blown highlights from looking so bad?

[kmoreau893]

In the natural course of shooting, I'm using the FS100 mostly for documentary shooting at this time, and right now I'm using Frank's G-LOG B 1.1. I'm still wrestling with a PP that gives me the most latitude, I don't mind grading, but I'm having a hard time with how the FS100 captures overexposed highlights. I can't always protect the highlights or the rest of the image will be too dark. With the Canon EOS, blown highlights usually look pretty good, especially if they are out of focus, they have pleasing edges. My style is to sometimes shoot into light sources that might be in the frame.

However, with the FS100, the blown highlights look really bad, with no transition and very hard edges, like the sensor just clips on the pixel. Without doing a whole lot of testing and experimenting with knee, levels and PP, can anybody advise me, I would imagine I'm not the first to experience this. I can post images if necessary but I figure this is a common problem with hopefully an easy solution that I'm missing.

Thanks for any advice.

-Keith

 

[morgan_moore]

My advice - and others disagree - is to put the knee at 105

This is a profile for including blown highlights - not protecting them which is what the flatter profiles are about

Also under expose just a tad and use fill and reflectors where possible



Out of the camera..
https://vimeo.com/39442216

(the wide shots are 5d)

S

 

[kmoreau893]

Thanks Sam, can you tell me what base picture profile you use, other than the knee setting?



Here's an example of what I'm getting - there is light coming through the slats in the windows, can you see the very sharp edges where it is blown out? The other highlights have a translucent drape, and this cuts down the light a bit, these are ok, and those edges are ok, but the crosses where the light is a bit more intense look terrible. I'm going to have to blur them in post.

 

[kmoreau893]

And here's the thing, I'm pretty sure I could have shot the same exact thing with a 5D MK II and the super blown highlights would not have occurred. I haven't done tests but I have shot similar things, into light sources and really have not seen this with the Canon EOS. Any comments? It's really starting to bother me and I need to resolve it. Thanks much for any other advice.

 

[Gary W]

Why not shoot a scene like this a stop lower and vignette your talent and bring them
up in post.

 

[Zephyrnoid]

Ah the digital paradigm!
"how the FS100 captures overexposed highlights. I can't always protect the highlights or the rest of the image will be too dark."
Answer?
Lighting. You can't escape that after audio, lighting is King.

Great Script
Great Directing
Great audio
Lighting
Camera
Editing

 

[morgan_moore]

My profile is everything else untouched, just down a couple of clicks on red, Cinegama2,

Yep IMO the 5d has better rolloff - I dont know if it is less DOF, the bigger chip, better use of colour by the blokes who designed the sensor .. or what

Your example is a little strange - maybe too much DOF - too sharp lens - maybe up the light if possible - at least you dont have any flourecent highlights

I think the key to the FS is not to stress it too far- learn its limits - as with all tools and it works brilliantly within them
Exposure has just sort of clicked for me in the last month

S

 

[morgan_moore]

Ah the digital paradigm!
"how the FS100 captures overexposed highlights. I can't always protect the highlights or the rest of the image will be too dark."
Answer?
Lighting. You can't escape that after audio, lighting is King.

Great Script
Great Directing
Great audio
Lighting
Camera
Editing

I just dont think that is true - you should be able to have some blown material in the frame - yep lights are good but to fill that window down would probaly need a 3k indoors .. and then would look artificial anyway

S

 

[kmoreau893]

Thanks for the advice, Sam. Have you encountered this 'hard edged' highlight handling before? I noticed in your bicycle shoot there was a lot of backlight, like sky between the trees, but I didn't see the harsh blown out quality I'm seeing.

For the other posters, of course I'm aware of using lighting to balance the contrast. I'm a pro and have done this for many years. I could have put a ND gel in the windows, that would have gotten it down. When I shot it I noticed it a bit on my Small HD DP6 reference monitor, but when I had a chance to look more closely these super-overexposed highlights looked different than the normally exposed highlights. Its like the FS100 does some strange ultra-clipping when the input light level gets to a certain point. However, specular highlights should not look this artificial and hard-edged. I've shot into similar situations even with my EX1 and with specular highlights and it doesn't look bad like this. The only time I've seen bad specular highlights as bad a this was on my old tube video cameras.

However, as a documentarian in run and gun situations, I cannot always control the light, this was an interview so I had some control. But in the field you can't control this. I don't want every reflection of the sun or strong light sources to look this bad, I can't control it.

I'd like to hear from some people that have experienced this strange, hard-edged highlight, maybe it's my PP settings (right now GLOG B 1.1). I guess I'm going to have to do some tests with various PPs and settings and AB them with my Canon EOS gear to see the difference. This might be a deal breaker for me, though I've had the FS100 since October of last year.

Thanks all.

 

[Dermot]

my colorist/finishing artist advice is to protect the highlights on all digital camera's, maybe an exception for Epic with HDRX turned on and low movement in the shot.. but other than that.. protect the highlights.. for old school folks, it's like you are shooting reversal <shudder>

;-)

d

 

[kmoreau893]

As a colorist and finishing artist, you also realize there is no way to protect specular highlights unless you are doing extreme HDR, which really doesn't exist in video. Specular highlights are present in every kind of video and film. What I'm objecting to is a super-white blob with hard edges that shows up in my footage which doesn't blend in at all with anything else. If I try to protect this by lowering the exposure, everything else will be too dark, so this is not an option in some situations. As an experienced colorist have you seen that in FS100 footage vs Canon EOS or other footage?

Over and over I have heard that the FS100 weakness is in the highlights, but you cannot always control some highlights. I understand there will be a loss of all detail in the highlights and I accept that, but I need a solution that will not produce a strange blob when I shoot into light sources, it's just not acceptable.

When I have time I'm going to do some tests and compare, with the same subject and light sources the FS100 with other camcorders / DSLRS and try to get to the bottom of this. Perhaps the Picture Profile I'm using is responsible for it. (GLOG B 1.1.).

Thanks again everyone who's provided input.

 

[morgan_moore]

Thanks for the advice, Sam. Have you encountered this 'hard edged' highlight handling before? I noticed in your bicycle shoot there was a lot of backlight, like sky between the trees, but I didn't see the harsh blown out quality I'm seeing.

For the other posters, of course I'm aware of using lighting to balance the contrast. I'm a pro and have done this for many years. I could have put a ND gel in the windows, that would have gotten it down. When I shot it I noticed it a bit on my Small HD DP6 reference monitor, but when I had a chance to look more closely these super-overexposed highlights looked different than the normally exposed highlights. Its like the FS100 does some strange ultra-clipping when the input light level gets to a certain point. However, specular highlights should not look this artificial and hard-edged. I've shot into similar situations even with my EX1 and with specular highlights and it doesn't look bad like this. The only time I've seen bad specular highlights as bad a this was on my old tube video cameras.

However, as a documentarian in run and gun situations, I cannot always control the light, this was an interview so I had some control. But in the field you can't control this. I don't want every reflection of the sun or strong light sources to look this bad, I can't control it.

I'd like to hear from some people that have experienced this strange, hard-edged highlight, maybe it's my PP settings (right now GLOG B 1.1). I guess I'm going to have to do some tests with various PPs and settings and AB them with my Canon EOS gear to see the difference. This might be a deal breaker for me, though I've had the FS100 since October of last year.

Thanks all.

I shoot in the world too - no time for ND on window and as you say total exclusion of specular clipped highlights is just not going to happen

I am convinced that the Knee must be at 105% - so yes your profile may have a lot to do with it

I think the FS100 is worse but I feel after months of playing that it is coming togeher for me

Seems to be the combination of a profile at 105%, mild under exposure, fill where possible, selection of location (shade) , typically backlighting, wider Tstop to soften the OOF areas, and maybe my crummy old 1980s glass, plus a Tiffen VND filter

ALso if I need to I will desat the tops in post.. (watch it through first you see graded, then ungraded)
https://vimeo.com/34622682
Proof that you cannot protect the highlights.. (the grainy shots are me pulling the under exposed areas back up!)
https://vimeo.com/33871036

S

 

[Dermot]

Oh yea i have seen 7D & 5D & FS100... they all can get pretty ugly when clipped, but then so does the Epic without HDRX that i was gradeing yesterday, and when the highlights are gone, they are gone, gone, gone...

Like you i use something like DFT's ProMist in the top 5 ire to roll off an otherwise harsh clip, and de-sat, this is kinda the norm for just about anything that's clipped out... i can show you Alexa footage, F3/Slog/DPX and on and on that show the same issues, and the starting point to deal with it is the same.. fortunatly it's dead fast and easy.. for me one click and it's RT in my system in 2K, so i don't really look at it as a big deal to sort it, rather not, but no biggie

A question i have - you did not see this in the monitor on set, so could you have added a clip somewhere in the post prod chain? Is the camera orignal still avb? How does it look if you re-wrap it to h.264, and open up that on your desktop in Qt player?
You had not seen it on set, and that's pretty easy to see even on a 4" screen.... so it may not really be there, i'm hopeing what you saw on your camera's screen is really what was captured, and the artifacting is a post chain issue... i know if that appeared in my suite, my first question would be "where's the camera orignal?"

Another thought is that it's an artifact from compression, as the screen is showing you the output before compression - but that seem very unlikely...

I shot for years, doco's around the globe with a 16mm camera, now maybe a few time every year i go out and shoot something... old habits, and fun, a few weeks ago i was in Tamil Nadu pointing a camera for a doco, very much run-n-gun in 100 degree heat and hard, hard sun.... the FS worked fine, no harsh clipping in 13+ hours of rushes some blown highlights and plenty of deep, deep shadows that i can dig into and bring up to where i want them.... with moderate noise reduction - I'm using a takeoff from AbleCine's "technicolor style"... so not an aggressive profile atall.

But mainly i grade/finish - my daughter asked me to stay home, stop traveling 200+ days a year... so i did....

In the last year i've graded features shot on Epic, Alexa, F3/SLOG, Film, EX, 7D.. MOW's shot on MX, F3, HP3700, Doco's shot on EX1/3, 7D, 5D and shorts/ TVC's shot on FS, Epic, MX, 7D, EX, Film... so just about everything.... i can say with out a moment's hesiatation that the only camera that truly challenged me was the HP3700.... talk about clipped out highlights... Oy!

 

[kmoreau893]

Dermot - thanks for the info: I did see the clipping on set, but it was small though I did note it looked strange and I was a little concerned. When I looked at it later on a 24" grading monitor along with some other footage I just shot it clicked that this is happening a lot. It is in the original AVCHD footage, as well as the on set HDMI out, so I think it is a pre compression issues, somewhere between the sensor and the AVCHHD compression. It looks the same original, wrapped it's just the edges are hard.

I'm going to do some tests when I have time. I think I may have to try another profile other than the GLOG at this point, I'm not getting what I want out of it after a few attempts at color correcting it. I was thinking of the AbelCine Range, which I shot on originally and I liked a lot, maybe I'll bring down the reds a bit to try to avoid the red clipping problem, as well as extend the knee to 105 as Sam suggests, I didn't think at all about using the Cinestyle but I'll look into it. What variations on AB Technicolor did you tweak?

 

[Dermot]

K;

my camera is at the office, i'll drop as note when i get in there tomorrow.. at home right now, using this for avoiding/evadeing household chores ;-)

d

 

[mraaron895]

Here's my process:

Slightly underexpose incamera, in favor of higlights.

During the color correction process I bring up the levels to my liking

Because I color with Magic Bullet I use a Hilight Shoulder effect. I can then dial in the amount of information i want to retain in my hilights

I also add a slight bit of diffusion in post to soften the mids to highs

 

[Zephyrnoid]

However, specular highlights should not look this artificial and hard-edged. I've shot into similar situations even with my EX1 and with specular highlights and it doesn't look bad like this.

Sorry. your window illumination is NOT specular light, but with all your experience you knew that right? Specular LIGHT sources or reflected highlights thereof, are by definition point light sources such as in the example attached- the Sun, a muniscal reflection of the sun off a chrome bumper, a 1K at 500 yards.
The 'Boxed' illumination entering the window is refracted light that has been chopped up by the window sashes. THAT is why it's clipping in that shot, versus in a pic with unfettered specular illumination.
Sorry to be so harsh and not to be disrespectful, but you have confused terms and thus your puzzlement at the phenomenon.
Shoot some tests. I bet you can repeat the specular vs refracted lighting variance .

 

[kmoreau893]

No disrespect taken, I appreciate the clarification. I did misuse the "specular" term, but although I'm not sure if I agree with how small a specular highlight can be. In any case it is a very overexposed highlight, and I don't think that the way the FS100 captured and presented this highlight is very graceful. I have seen the same 'blobbiness' on other light sources.

I don't think that my misuse of the term 'specular' has anything to do with why the FS100 handled these over-exposed areas so harshly. However, you mention that 'refracted light' is the reason for this strange handling of the highlights, and I don't agree. While the light is refracted a bit through the glass in the window, whether it was direct light or refracted, I feel the edges are way too harsh and out of place.

If you could explain further, why should refracted light (which I don't think has anything to do with the problem, I think it was just a very bright light source from outside (i.e. the sun) that was shining more powerfully through the sashes) be the reason for the problem? It is in the same plane as the less exposed light on the translucent curtains and that plane is really out of focus. I have seen similar harsh edges when aiming into direct light sources. In your example above, the highlights are handled well, with my theory, the rim light on her right side would be blobby and harsh, but here we get a nice transition. Was this done on a FS100?

I will shoot some tests and get back to the people here. However what I would like to know is if other FS100 owners have experienced this problem when shooting into light sources and what they have done about it, other than 'avoid it, reduce the contrast ration of the scene, etc. So far Sam has been the only one that has given me, what I feel is usable advice about how to resolve this 'real world' issue.

Anyway, thanks again for any and all input!

 

[Zephyrnoid]

OK. Keeping it simple
The light hitting the glass panes in your FS-100 grab is refracted as it enters the glass, which spreads it, creating a BANK light effect.
The Sun in the FS-100 grab shown is specular par excellence because it's effectively a POINT
The reason your windowpane shot clips at the edge of the sashes is not because the source light is specular or refracted, but because the contrast is SO ABRUPT at those edges. Brightness has nothing to do with it. Indeed, your original idea of cutting the actual brightness down using ND gels or my preferred solution, Inside Fill would help to solve the problem of 'keystoning' as we call it. The odd thing is that your phenomenon really looks like a sharpening setting in camera which would definitely clip highlights like that.

 

[kmoreau893]

Thanks, good explanation, but my sharpening is pretty much all the way down on this picture profile. When you are shooting from a dark stage onto a stage light, the contrast is very abrupt as well. Here is a screen grab from a shot from my 5D MK II, similar situation, but we don't get the weird edges, the edges of the light look natural and defocused, whereas I bet if I shot the same thing with this current PP on my FS100 I'd get the same phenomenon. So any idea what what is going on?