Clipping Highlights

[Pawel Achtel]

Sanjin,

What Macgregor did was to push the brightness up by setting 250ISO and pulled it back in with the curve. These would sort of cancel each other except that, because setting ISO is linear and curve is not, the mid-grey level is placed in different spot now. The result is that your display path (not what is recorded in RAW) will show image more like it should be without hiding the extra stop in the highlights. His curve was carefully chosen and corresponds to the "digital" stock which, unlike film, needs to have a knee applied in order to protect the highlights. He applied this knee in the preview path. This is helpful for the DOP and it is helpful for the client because WYSIWYG unlike the linear default display in Red One where you just don't see the clipping on your monitor. I much prefer to see the full DR after the curve was applied, others may not like that.

With all due respect, why don't you read the posts carefully and try to understand what he and others say before making a fool of yourself? If you don't understand, it's OK to ask. Be polite and respectful. Chances are that these guys have decades of experience and Macgregor is one of the most respected and educated operators on this forum. There are many helpful and patient users willing to explain. There is nothing wrong with that, OK? :thumbsup:

 

[Sanjin Jukic]

Sanjin,

What Macgregor did was to push the brightness up by setting 250ISO and pulled it back in with the curve. These would sort of cancel each other except that, because setting ISO is linear and curve is not, the mid-grey level is placed in different spot now. The result is that your display path (not what is recorded in RAW) will show image more like it should be without hiding the extra stop in the highlights. His curve was carefully chosen and corresponds to the "digital" stock which, unlike film, needs to have a knee applied in order to protect the highlights. He applied this knee in the preview path. This is helpful for the DOP and it is helpful for the client because WYSIWYG unlike the linear default display in Red One where you just don't see the clipping on your monitor. I much prefer to see the full DR after the curve was applied, others may not like that.

With all due respect, why don't you read the posts carefully and try to understand what he and others say before making a fool of yourself? If you don't understand, it's OK to ask. Be polite and respectful. Chances are that these guys have decades of experience and Macgregor is one of the most respected and educated operators on this forum. There are many helpful and patient users willing to explain. There is nothing wrong with that, OK? :thumbsup:

Pawel,

why should I fool myself because I know that earlier before all this 'aggressive ISO "issue" pressure to RED' even started

and I never heard that any successful RED project till today did use this profile.

The most professionals worked from the beginning with a notion of 320 ISO in camera and "effective" ISO...

at each particular shot (one above is from the test dated at 8/20/2008).

The point is that you can "profile" every shot only if you use right tools and work with that directly in a field but it

is almost impossible to have a profile that could be somehow universal for the most of shots.

Or to be more precise you can "profile" only for studio shots with fixed and precise measured tungsten lighting, etc,...

for all other situation (mostly outdoor in available light) you would have to build a new profile each time.

Available light consists conditions which are always changing.

One more thing:

If this sort of "profiling" would always work successfully then would be provided by RED from a day one.

So let us have a look what they will bring with their latest offer called "RED Color Science"...

 

[Dan Hudgins]

Should one avoid clipping?

Should one avoid clipping?

Since my first wording on this post was not quite clear enough I have made adjustments.

==

Clipping over large areas of the frame never needs to happen in a Film or Digital, if it does it should be a choice, otherwise you are falling victim to a producer who did not budget enough generator trucks. Does one want to participate in the making of "films" that represent the "new" Digital clipped esthetic? If you cannot get the "tools" you need to control the contrast range of the subject matter, and you want to work, then what standards do you keep, none? [I added "large areas" since some small specular reflections might be brighter than white subjects that are exposed higher than normal, but part of lighting is to control the subject matter and exposure in the frame to reduce the percent of the frame that is "out of range" highlight and shadow, with negative film the extra highlight range gives results that can show up in film to film printing that may not show up in digital scans of those film negatives, so looking at digital images of film capture becomes an issue of where did the supposed clipping happen]

You set the exposure to hold the brightest important subject matter in the shot, the add enough fill lights to keep the dark parts bright enough to avoid noise, that's the DPs job to make sure the shot is exposed right for post. [I did not imply that anyone should change the ISO of the camera to control exposure here] [I changed "point" to "important subject" since that seems to have caused confusion, sorry]. (Even so, things brighter than the "important subject" would not be so bright as to not register some density change on negative films when the fill light is bright enough to control the contrast ratio and other measures are taken as needed.)

Maybe some people want movies to look like the news or youtube, but that is a pollution of the art of cinema. [I would add that even if documentary people shoot Super16 to avoid the clipped "video" look, so when film is gone, will digital cameras have as much range as film, or will we just live with compressed clipped images as the best one can get?]

==

With regard to film, [negative] film does not clip, the contrast rolls off as the exposure increases, if you have a high contrast shot to do, you pull process and get more lights, that is it.

==

I would add that the 12bits the RED ONE "could" shoot, it does not since the sensors are off balance most of the time, the de-moasic software clips the highlights of two of the colors to match the most exposed one, reducing the number of bits of dynamic range.

If you shoot under 2600K lighting without using enough blue filters to bring that back to daylight balance you are dropping about three bits, so you are only getting about 9bits of dynamic range, if that.

RED Co. did not take into account shooting with the sensors blanced by using a pinkish filter etc. to get the full 12bits of dynamic range, and since the de-moasic clip points cannot be adjusted by users, this option is not there(?). If you could gain another stop of range it would help reduce clipping.

DRX is not a substitute for balanced light to the sensors, although, for monochrome output, shooting unbalanced and using DRX might give you more than 12bits of range. Using more that one RED ONE for HDR, would be an option if the RED ONE sensor did not solarize at too low of a brightness.

My point was to seperate some issues that may seem intertwined,

1) Should one try to avoid clipping?

2) Negative film does not hard clip, but may look clipped in digital scans. With digital projection will one loose the ability to see any of films advantages over digital production?

3) If one should avoid clipping, what methods used in traditional filmmaking can help. What are the costs of avoiding clipping, how much does it cost for the extra lights and studio sets?

4) Will there be less effort to avoid clipped images as viewers get accustomed to seeing them in the theatre, and all production converts to digital.

5) If there is no resistance to producing clipped images from filmmakers then who will resist, will the box office drop enough to send a signal to producers?

 

[Andrew Wilding]

Pawel,

why should I fool myself because I know that earlier before all this 'aggressive ISO "issue" pressure to RED' even started

and I never heard that any successful RED project till today did use this profile.

The most professionals worked from the beginning with a notion of 320 ISO in camera and "effective" ISO...

at each particular shot (one above is from the test dated at 8/20/2008).

The point is that you can "profile" every shot only if you use right tools and work with that directly in a field but it

is almost impossible to have a profile that could be somehow universal for the most of shots.

Or to be more precise you can "profile" only for studio shots with fixed and precise measured tungsten lighting, etc,...

for all other situation (mostly outdoor in available light) you would have to build a new profile each time.

Available light consists conditions which are always changing.

One more thing:

If this sort of "profiling" would always work successfully then would be provided by RED from a day one.

So let us have a look what they will bring with their latest offer called "RED Color Science"...

I think the only explanation for Sanjins seeming insanity is a language gap. I think perhaps he thinks that Macgregors Look Profile is somehow meant as an insult to the Red - an insinuation that it doesnt perform well in lowlight, maybe?

 

[Pawel Achtel]

why should I fool myself because I know that earlier before all this 'aggressive ISO "issue" pressure to RED' even started

His approach is more conservative...if you just took a moment to understand it.:frown2:

...and I never heard that any successful RED project till today did use this profile.

I never heard about one that failed because of it and Macgregor clearly demonstrated a spectacular failure (overblown highlights) when exposing grey correctly at linear 320 ISO, and not using his profile.

 

[Sanjin Jukic]

His approach is more conservative...if you just took a moment to understand it.:frown2:


I never heard about one that failed because of it and Macgregor clearly demonstrated a spectacular failure (overblown highlights) when exposing grey correctly at linear 320 ISO, and not using his profile.

I understood that from the first moment but was thinking more about other "consequences"... :yikes:

and we are still waiting for more proper answer from RED about it... I doubt if any answer is needed anyway...

 

[HBrennan]

What "consequences" do you see that are so dire? What makes you so terribly against macgregors profile? I've used it and the camera didn't self descruct... I'm wondering what the big hoo-ha is...

just curious... not taking a stab...

 

[Sanjin Jukic]

What "consequences" do you see that are so dire? What makes you so terribly against macgregors profile? I've used it and the camera didn't self descruct... I'm wondering what the big hoo-ha is...

just curious... not taking a stab...

I do not have time right now to repeat again all what I wrote but if

you would have time then you could read it... again, takes time but

if you are so curious and wondering then...

let you know one thing from the beginning that it's more about a camera "political" issue then it is a technical...

good luck...:beer:

 

[David Mullen ASC]

You set the exposure to hold the brightest point in the shot, the add enough fill lights to keep the dark parts bright enough to avoid noise, that's the DPs job to make sure the shot is exposed right for post.

That's not really the way you expose shots in a movie, for three reasons:

1) consistency in noise level in a sequence. You don't want one angle to be shot at the equivalent of 1000 ASA and the other to be shot at the equivalent of 100 ASA just because one had a brighter object in the frame than the other. This is the difference between still photography and movie photography, that shots have to be consistent to each other within a sequence. Generally you expose for consistency in noise for the midtones, like the face of the actor.

2) some clipping is not only unavoidable, it's completely acceptable. Clipping just means overexposed without detail. The camera can only record "x" number of stops and reality has many more stops of brightness than that. If you are shooting someone standing outside in the sun and a white van drives by and the sun momentarily glances off of the windshield, even if you lowered the exposure for the white van, the sun reflection would be clipped, and if the subject was in the shade, and the white van was in the sun, the van itself would be clipped. However, the issue is whether that's a "mistake" or not because the van was in frame only momentarily, you may not miss the lack of detail in the white surface, and the van might not even be in focus! So to make that white van the determining factor in how you expose the shot is ridiculous, especially if it means making your lead actor in the shade look noisy because you've exposed for an unimportant object moving quickly in the background.

Or how about a dark room being explored by flashlight -- are you really going to expose the shot so that the filament inside the flashlight is captured with detail and not clipped? Or how about a car at night driving past the camera, it's headlights flaring the lens? Is it important that the headlamps themselves have full detail with no clipping?

And beyond sort of obvious examples like that, what about creative use of overexposure? Someone walking in a white limbo for example? Do you really need to record every scuff mark on the white wall of the cyc? You deliberately want it clipped -- i.e. white with no detail.

3) What about creative lighting and using as much available light as possible? You don't want lighting to become a technical exercise about getting rid of noise and clipping. If you set the exposure for the brightest object in the frame and then raise all the surrounding light levels to compensate, you may destroy the natural ambience of the room and create a very "lit" look to the scene. Sometimes the most natural look, for example, is to light a room with actual table lamps, but at the expense of letting the lamp shades get a bit clippy. If you exposed for the lamp shades, then you'd have to add more off-camera light for the actors, and now you no longer have the natural look of people being lit by the glow of the lamp shades.

The amount of clipping to allow in the frame is a judgment call, both creative and technical. One guideline is how distracting and unnatural the clipping is -- if it's a person's shirt in a medium shot, that's pretty distracting. If it's a small out-of-focus object in the far background, more than likely it's not going to matter. If it's a small area on the actor, it may not matter, like a white shirt collar in strong backlight.

The point is that you don't to ruin a good shot simply because you are automatically exposing for the hottest point in the frame, and the other point is that you have to consider the continuity of noise level from shot to shot.

 

[Gavin Greenwalt]

Clipping never needs to happen in a Film or Digital, if it does it should be a choice, otherwise you are an amateur falling victim to a producer who did not budget enough generator trucks. A profesional would walk off the set if the producer does not give him the power he needs to light, for the sake of the industry you strike.

Uhhh... I have 3D renders that clip all the time.

I challenge you to create a scene that looks aesthetically pleasing which doesn't clip somewhere.

I usually have that data in the exr to pull it down if necessary but even with literally infinite 'power' you're still going to have hotspots. If you know what your final grade is going to look like there is no reason to capture a lot of detail in the sky for instance if you are trying to keep your shadows clean.

---

Personally I'm actually forcing myself to overexpose 1-2 stops from what I would expect. In the last year I've been burned by underexposed shots by about 4:1 over overexposed so I'm trying to change some habits after being paranoid for years with DV cameras and religiously protecting my highlights. So far it's been a success.

 

[Sanjin Jukic]

That's not really the way you expose shots in a movie, for three reasons:

1) consistency in noise level in a sequence. You don't want one angle to be shot at the equivalent of 1000 ASA and the other to be shot at the equivalent of 100 ASA just because one had a brighter object in the frame than the other. This is the difference between still photography and movie photography, that shots have to be consistent to each other within a sequence. Generally you expose for consistency in noise for the midtones, like the face of the actor.

2) some clipping is not only unavoidable, it's completely acceptable. Clipping just means overexposed without detail. The camera can only record "x" number of stops and reality has many more stops of brightness than that. If you are shooting someone standing outside in the sun and a white van drives by and the sun momentarily glances off of the windshield, even if you lowered the exposure for the white van, the sun reflection would be clipped, and if the subject was in the shade, and the white van was in the sun, the van itself would be clipped. However, the issue is whether that's a "mistake" or not because the van was in frame only momentarily, you may not miss the lack of detail in the white surface, and the van might not even be in focus! So to make that white van the determining factor in how you expose the shot is ridiculous, especially if it means making your lead actor in the shade look noisy because you've exposed for an unimportant object moving quickly in the background.

Or how about a dark room being explored by flashlight -- are you really going to expose the shot so that the filament inside the flashlight is captured with detail and not clipped? Or how about a car at night driving past the camera, it's headlights flaring the lens? Is it important that the headlamps themselves have full detail with no clipping?

And beyond sort of obvious examples like that, what about creative use of overexposure? Someone walking in a white limbo for example? Do you really need to record every scuff mark on the white wall of the cyc? You deliberately want it clipped -- i.e. white with no detail.

3) What about creative lighting and using as much available light as possible? You don't want lighting to become a technical exercise about getting rid of noise and clipping. If you set the exposure for the brightest object in the frame and then raise all the surrounding light levels to compensate, you may destroy the natural ambience of the room and create a very "lit" look to the scene. Sometimes the most natural look, for example, is to light a room with actual table lamps, but at the expense of letting the lamp shades get a bit clippy. If you exposed for the lamp shades, then you'd have to add more off-camera light for the actors, and now you no longer have the natural look of people being lit by the glow of the lamp shades.

The amount of clipping to allow in the frame is a judgment call, both creative and technical. One guideline is how distracting and unnatural the clipping is -- if it's a person's shirt in a medium shot, that's pretty distracting. If it's a small out-of-focus object in the far background, more than likely it's not going to matter. If it's a small area on the actor, it may not matter, like a white shirt collar in strong backlight.

The point is that you don't to ruin a good shot simply because you are automatically exposing for the hottest point in the frame, and the other point is that you have to consider the continuity of noise level from shot to shot.

David,

thanks for your kind and professional explanation about exposure and clipping!

And you rock!!!:beer:

 

[Dan Hudgins]

Highlights

Highlights

Traditionally some of the highlight issues might have been dealt with these ways:

1) Dulling spray or black spray paint or tape etc. would be applied to chrome or other reflections in a shot to cut them down.

2) Windows can be gelled (or net) to reduce their being out of range.

3) Carbon arc lights were routinely used outdoors to reduce contrast ratios.

4) Car headlights can be dimmed or dulled, so can Practical Lighting.

5) Shoot night for day (not day for night). If you shoot daytime shots at night you can light them to any ratio you want since all the light is under your control.

6) Don't be afraid to have the subject in Silhouette with the background exposed in the range of the sensor. It was common to shoot actors in Silhouette when film was not fast enough, you used the light from the background to give form. If you over fill such a shot it is not as dramatic anyway, and it does not help to over-expose since the lens flare will wash out the subjects outline.

7) Just avoid the sky or other bright background in shots, and use longer lenses to allow you to frame the subject more selectively.

8) LC filters might help a little, they take light from the bright areas and bring up the fill areas, with the R1 the compression artifacts may be less in the shadow areas if they are lifted by the LC filter, maybe someone can show some tests of H&H LC #1 to LC #5 filters graded out to match so we can see if the compression interacts in a positive way?

==

Since sensor based cameras can have less overexposure range than negative films, the need to control the contrast ratio of what is in front of the camera is more important, yet it seems some productions using these cameras are trying to shoot under conditions and high contrast ratios that would not be used in traditional studio system filmmaking.

==

Since film was included in the set of "clipped" shots, it has some bearing on the topic of exposure, negative film does not need to clip, although scans of it might. If you bleach bypass the negative you might get some blocked up highlights, but in scanning one can probably extract more detail if you adjust the brightness of the scanner light source.

Sensor cameras clip, and yes there will probably be some small highlights that will be out of its range in most shots unless you have control of what is being shot and put tape over them or take other measures to adjust the content of the subject matter.

Having more than about 5% of the frame in a shot clipped is another issue.

==

If you are shooting a sequence there would be little reason to adjust the ISO of the camera, you would adjust the iris, shutter opening, and lighting wattage. Just as in film shooting. Adjusting the ISO within the whole project is undesirable, just as pushing film for one shot would be because the grain would stand out and if you increase the contrast for one shot in a sequence the other image qualities would not match.

From what I understand Kubrick pushed ALL of Barry Lyndon (1975) one stop, that way the grain and contrast would match for the whole work.

==

On converting from negative film with its soft sholder to digital with its sharp clipping there will need to be some acceptance in a change of ascetic quality of cinematic images, since you will not end up with the same results.

A bigger issue, is should one try to have Digital "filmmaking" look as close to film filmmaking has developed (prior to DI scanning), or should the whole notion of what makes for desirable results be changed to embrace and celebrate blasted out clipped digital images (since those are easer and lower cost to get anyway)?

 

[Sanjin Jukic]

Dan,

thanks for this technical explanation too.

After all those explanation(s) we can think even more how to make our (R1) moving images better.

 

[Dan Hudgins]

Cutting corners

Cutting corners

...we can think even more how to make our (R1) moving images better.

I hope people using their R1 do not try to cut too many corners, the R1 can make fine images, but you cannot point it anywhere at any time just as you cannot do that with a film camera. The methods used in traditional filmmaking need to be used with the R1 to bring the finished results up to the same standard. A LUT is not a substitute for good lighting and art direction.

You need to think of the many reasons why filmmakers moved from shooting on location to shooting in the studio in the first place, then later tried to shoot with studio techniques on location. If you abandon all that technique and experience in the control of light and contrast ratio etc. you are back to the time before the language of cinema developed...