Ask David Mullen ANYTHING

[David Mullen ASC]

There's no difference in look or effect between a linear and circular polarizer -- most polarizers used in the film industry are circular because video taps in some cameras use semi-mirrored surfaces, etc. which are affected by linear polarizers. Same goes for any camera with TTL focusing and metering. So the safe thing is to get a circular polarizer though I don't think it affects the RED one way or the other.

[Roberto Lequeux]

If linears didn't affect Red at all, would you go with two linears or one circular in your package? We will likely only have 3 stages in our big MB. I wonder if an IR and two linear polarizers would be enough for sunny days in the snow without having to close down the iris past f/5.6. If I understand correctly two of them can give you up to 2 stops of ND. Or we could use the IR, Pola and heavy ND.

I am very confused about polarizers. An other question I have in my mind is if you can get the same degree of control with a circular and a linear in terms of its polarizing feature so as to be able to dial it in and avoid weird skies while trying to get close to what we want on the glare from the snow.

If you know of any good links to check out I'd love to read those before I continue bugging you with these basic questions.

[David Mullen ASC]

There's lots of photo board discussions on polarizers if you do a search. From what I gather, it doesn't make a difference which you use, but I'd get circular polas myself because you never know what other types of cameras you'll need to put it on.

A pola and IR by itself isn't enough for sunny weather. I'm not sure an IR even has a stop-loss, but the pola is a stop and a half generally.

In direct frontal sunlight at 50 ASA, you get an f/16 at a shutter speed of 1/50th, which is the old "sunny 16 rule". So you need over two-stops of ND to get the RED down to 50 ASA at f/16. But let's say you rated the RED at 200 ASA, so that's an ND.6 to get to 50 ASA, but you're still at f/16. If you want to shoot at f/5.6, that's three more stops of ND, or five-stops worth altogether. So you'd have to sandwich your Pola with an ND.9 at least, if not an ND1.2. Of course, I'm talking worst case scenario, brutally hard frontal sunlight. But on white snow, you may want to bring down the exposure even more.

[Roberto Lequeux]

Exactly what I was hoping for in your answer, thanks.

I am making sure to have a set of three solid NDs including a 0.9 and 1.2... So it seems from your post if I understood correctly that in the worst case scenario we'd at least be in the ballpark. Unless we felt we really needed to underexpose a bit more to save more info on the snow. I am very concerned with the snow personally. The location is a character and I would love it if 75% of our shots with snow in them had vast quantities of detail in the snow. Perhaps we should also try to get a good IR + ND filter, and then with the polarizer and a 1.2 ND we would be covered?

I called and unfortunately Schneider is only currently working on one, so I might have to go with a different brand for the IR filter so I can get a matching set?

[David Mullen ASC]

Ideally, you'd have an ND/IR combo and a Pola. Now whether you'd need a straight IR is questionable because I'm not sure if the IR problem is noticeable until you have to use heavier ND's. But it sounds like you are covered. An ND soft edge grad and maybe an attenuator may be useful too for dealing with snow, when the Pola isn't really doing anything.

I find that I use an ND.6 soft edge grad and an ND.6 attentuator (for really wide-angle shots) more than any other strength of grad. ND.3 grads are too subtle to be worth the bother, and ND.9 grads are too dramatic and obvious most of the time.

[Kim Frank]

And another question about Chinese Laterns if you don't mind:

Janusz Kaminski ASC Mag. August ‚98 about FINDING PRIVATE RYAN
"I’d tested China balls in the past and never liked their effect, but I’m learning more about how to use them now. The key is to underexpose by 11/2 stops. You also have to keep them just outside of frame but away from the walls, so you get that nice falloff in the light. Philippe Rousselot [AFC] has been using them for years, but if you look at his films, you’ll notice that the people are always positioned away from any walls. He may have a very soft China ball a few feet away from the actors, but everything falls dark behind them. Because there no other light reference in the frame, their faces still glow even if the shot is 11/2 to 21/2 stops underexposed."

What does 11/2 and 21/2 stops underexposed mean.
And does he mean using them as a key or fill light?
Can you assume why he would want them underexposed?
How do you use them?

[Roberto Lequeux]

Ok. I see. I was thinking of the IR alone in case we needed it for interiors or night shots where our lights where giving off too much IR which (as far as I remember) I think HMIs can do. We will have mostly HMIs so as to minimize blue channel issues even though we'll likely shoot with build 20 if we end up shooting on a R1.

I have a personal "fear" of grads and have avoided them mostly. Would you let out a long sigh if someone asked you to shoot without grads of any kind?

I would imagine that Epic-X 14-bit and even R1 would have enough information to bring back what you would do with a light grad anyway, though getting it recorded in the middle as opposed to the high end would give you a much richer negative to work with... I just don't know how hard it might be to un-do it if we later found out we rather go without the effect of the grad. In fact I am thinking more about how to move around with a few 4k HMIs to bring the actors up higher and make the overall image a tad flatter to get a thicker negative that way. It would be a pain but not so much if we had a nice team and snowmobiles pulling sleds with a pair of 5k gennys for two 4k's. An other pulling grip gear. It depends on the shot obviously and we wouldn't want to limit ourselves or make things too complicated.

How about this set:
_ IR
_ IR + NR 0.6 como
_ 0.6
_ 0.9
_ 1.2
_ Rotating Polarizer
_ Blue filter (for interiors lit with tungsten)

[David Mullen ASC]

If a grad can improve the shot, or solve an exposure problem, then it's an arbitrary "rule" to not allow them, without any scientific merit. I don't have a lot of tolerance for those sorts of rules placed on a cinematographer, the person hired for his photographic expertise.

I must have shot half of "Northfork" with an ND grad because of all the stormy and changing skies in Montana. And that was shooting film with its wider dynamic range. It allowed me to capture more details in the cloud formations.

I'm not necessarily talking about using grads for grad effects, which can be done in post, I'm talking about using grads to control exposure when the shot naturally allows for a grad to be used (like a static wide shot with a constant horizon line.) If something gets clipped, there is no detail in post to work with. And you never know when you'll come across a set-up where a grad can save you. Could be a shot of a line of dark trees at the top of frame and hot snow at the bottom of frame, and without a grad, you've got a choice between noisy trees or clippy snow.

Another time I've used grads is in a wide shot of a grocery store interior when the ceiling is a wall of fluorescent lights -- the grad can allow you to hold some detail in the bright ceiling. I've also used the vertically when one side of the frame was a wall of windows or bright curtain sheers.

[David Mullen ASC]

And another question about Chinese Laterns if you don't mind:

Janusz Kaminski ASC Mag. August ‚98 about FINDING PRIVATE RYAN
"I’d tested China balls in the past and never liked their effect, but I’m learning more about how to use them now. The key is to underexpose by 11/2 stops. You also have to keep them just outside of frame but away from the walls, so you get that nice falloff in the light. Philippe Rousselot [AFC] has been using them for years, but if you look at his films, you’ll notice that the people are always positioned away from any walls. He may have a very soft China ball a few feet away from the actors, but everything falls dark behind them. Because there no other light reference in the frame, their faces still glow even if the shot is 11/2 to 21/2 stops underexposed."

What does 11/2 and 21/2 stops underexposed mean.
And does he mean using them as a key or fill light?
Can you assume why he would want them underexposed?
How do you use them?

He just means that the key created by the Chinese lantern was 1 1/2 stops or 2 1/2 stops underexposed. Of course, he's probably talking about moody interior scenes like Rousselot shot, like in "Interview with a Vampire". Trouble is that he may not use a meter in the same manner as you do, so I wouldn't necessarily say that you should follow the same approach without testing it yourself. He wants them underexposed because he wants dimmer highlights, darker shadows, and the background to go darker. If he's keeping the Chinese lantern very close to the face, there is a fast fall-off so he's probably trying to avoid the highlights in the skin from looking too hot.

[Roberto Lequeux]

Did I say something that upset you? If so I am very sorry. I am just trying to learn from you David.

My photographic knowledge limitations aside David, I think you and I agree that if there is a chance to notice the grad in the shot then itis best to think about it very hard before going for it. But if you hale a lot stationary horizons then you could get a boat load of millage out of them.

Just FYI, I always trust my DP because I personally make sure they know WAY more about lighting, composition, color and camera placement than me. I don't want you thinking I am a little dummy that second guesses the director of photography all the time. I just want to learn because I know what I want, so the more I learn the easier I can make life on set to my DP and other crew members while saving money and time yet still managing to get what we need.