to 85 filter or not. Tungsten film in Daylight

[Albion Hockney]

Was wondering if anyone had thoughts on best practice. I have heard a lot of people no longer use color correct filters for correcting daylight and tungsten balance shooting on film. is it necessary? - this assumes the film is getting a log flat pass scan.

[David Mullen ASC]

I don't think this is a new trend -- John Alcott was doing this back on "Barry Lyndon" after all. It's just the opinion of some cinematographers that it isn't necessary. Certainly color negative has the latitude to handle it but that's not the same thing as saying it makes no difference.

 

It's all a matter of exposure -- and therefore density -- in each color layer. A tungsten-balanced negative shot under 3200K conditions will print at normal printer lights, but one shot uncorrected in daylight will have an overexposed blue layer (and perhaps an underexposed red layer, depending on how you rated the stock.) The printer lights will show this imbalance.

 

Does it make a difference? Just depends. On some telecine transfers, the heavier density of the blue channel may manifest itself as having less grain in the blues but more noise in areas like blue skies that got too overexposed, too dense on the negative. Color-correcting the blue-ish image back to normal may create a color cast to the image depending on the skills of the colorist; you may find flesh tones to be a little paler or you may find a certain brown tone creeping in because of adding warmth to a pale blue image to correct it.

 

But generally it is correctable. I think the way you should think of it is this: if I plan on only correcting it partway (for a cool tone) or all the way but no further (for a neutral tone) then go ahead, but if you think you may want to correct it all the way towards a warm look, then you'd be better off getting a more balanced negative either by using some degree of warming filter or switching to daylight stock.

 

So I tend to use this technique of tungsten film outdoors with no filter when I'm doing a winter movie where I want a colder cast, or a film where I want to emphasize blues and greens over reds (like in a forest maybe) but I'll use the correction filter or daylight film in a location like a warm desert where I want good saturation of the redder tones.

 

The other way to think of it is that generally a colorist prefers to work from a balanced negative as a starting point, rather than having to make a big correction just to get to the starting point. But as I said, it all depends on the final look you want. If the "correct" look is a bluefish cast, then getting it by using tungsten film in daylight uncorrected in a sense is giving the colorist a negative that is already balanced for the look with minimal correction needed.

[Albion Hockney]

This is everything I wanted to know! thank you very helpful

[Luke Randall]

Thanks David. I was curious about this too, fantastic explanation.

[Leon Liang]

What would be the main differences between using tungsten stock (filter or no filter) and using daylight stock?

[David Mullen ASC]

With Vision 3 stock, the differences are pretty minimal between the stocks, basically the faster ones are a little more grainy than the slower ones, and the blue layer is finer-grained (because it is slower) in the daylight stocks, but otherwise in terms of contrast, saturation, and sharpness, they are all pretty similar. Maybe a few generations ago in the EXR days, or Vision 1, you might have felt that the daylight stocks (50D and 250D) were a bit more contrasty.

[Leon Liang]

Thanks David.

[Mathew Collins]

 

So I tend to use this technique of tungsten film outdoors with no filter when I'm doing a winter movie where I want a colder cast, or a film where I want to emphasize blues and greens over reds (like in a forest maybe) but I'll use the correction filter or daylight film in a location like a warm desert where I want good saturation of the redder tones.

 

Is it because the blue layer in tungsten balanced film is more sensitive to blue light and

the red layer in daylight balanced film is more sensitive to red light?

[David Mullen ASC]

The blue layer has to be faster in tungsten balanced film to compensate for the lower amount of blue in tungsten light. I don't think they make the red layer any faster for daylight stock, there isn't a lack of red in the daylight spectrum.

 

I'm just saying that by not using the 85 filter in daylight in tungsten film, you've overexposed the blue layer relative to the red and green and therefore it prints at a higher number.

[Mathew Collins]

The blue layer has to be faster in tungsten balanced film to compensate for the lower amount of blue in tungsten light. I don't think they make the red layer any faster for daylight stock, there isn't a lack of red in the daylight spectrum.

 

I'm just saying that by not using the 85 filter in daylight in tungsten film, you've overexposed the blue layer relative to the red and green and therefore it prints at a higher number.

 

"or daylight film in a location like a warm desert where I want good saturation of the redder tones."

 

David,

 

How would this possible, if red layer of daylight balanced film isn't more sensitive?

[Bill DiPietra]

 

"or daylight film in a location like a warm desert where I want good saturation of the redder tones."

 

David,

 

How would this possible, if red layer of daylight balanced film isn't more sensitive?

 

Take a look at the Kodak Data Sheets for 5219/7219 & 5203/7203

 

David - isn't the blue layer always the most sensitive layer in both tungsten & daylight stocks? According to the data sheets, the sensitometry seems virtually the same...

[David Mullen ASC]

Yes, but to make a stock daylight-balanced, they basically make the blue layer slower compared to the red and green layers. Otherwise, how else do you make a stock daylight versus tungsten balanced? I suppose you could somehow "ND" the blue layer rather than make it slower...

[Mathew Collins]

Yes, but to make a stock daylight-balanced, they basically make the blue layer slower compared to the red and green layers. Otherwise, how else do you make a stock daylight versus tungsten balanced? I suppose you could somehow "ND" the blue layer rather than make it slower...

 

Thank you David.

 

What is the technology to make blue layer less/more sensitive? Is it by changing the size of silver halide crystals or based on the number of crystals in blue layer?

 

like, small size crystals for less sensitive blue layer(daylight balanced film) bigger size crystals for high sensitive blue layer(tungsten balanced film)

 

or

 

less number of crystals for less sensitive blue layer(daylight balanced film) more crystals for high sensitive blue layer(tungsten balanced film)

[David Mullen ASC]

The size of the grains affect the sensitivity, which is why slower film is finer-grained. And if the grains are smaller, there will be more of them within the same area compared to larger grains.

[Mathew Collins]

The size of the grains affect the sensitivity, which is why slower film is finer-grained. And if the grains are smaller, there will be more of them within the same area compared to larger grains.

 

Thank you David.