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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Ask David Mullen ANYTHING

David Mullen ASC said:
That's one of the things that I like about Blu-Ray, that there's enough resolution to finally see the grains in the film image. That said, grain can easily be exaggerated in a video transfer by over-sharpening the image, and sometimes the transfer is made from a second or third generation film element, though "Rain Man" is recent enough that I doubt that they would have to use old b&w separations to recreate the color image -- b&w separations tend to be grainier because they were created on an optical printer. Optical printer copies tend to optically edge-sharpen grain through the process of rephotographing the image through a lens onto a new piece of film -- contact printing tends to be smoother-looking.

But in this case, odds are that you are just seeing the grain structure of the original negative -- probably Kodak 5294 400T stock in this case. But like I said, all it takes is a bit of sharpening in post to make the grain stand out more. On the other hand, one of the number one complaints about Blu-Ray transfers is when they apply noise reduction to get rid of the grain.
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Thanks David! That helps me understand better. In terms of the second part of my post ... it doesn't seem like there's as much grain on the current movies being shot on film. Am I mistaken? Or are they applying "noise reduction" as you mentioned in order to make the image look cleaner?

Your answers are always much appreciated ...

Anthony
 
AnthonyFlores said:
Thanks David! That helps me understand better. In terms of the second part of my post ... it doesn't seem like there's as much grain on the current movies being shot on film. Am I mistaken? Or are they applying "noise reduction" as you mentioned in order to make the image look cleaner?

Your answers are always much appreciated ...

Anthony
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Modern 500 ASA stocks are finer-grained than they were in the 1980's, plus some movies may be doing a bit of grain reduction. And of course, some movies are shot digitally today. But the main reason is that high-speed stocks have improved tremendously in the past 25 years.
 
David Mullen ASC said:
Modern 500 ASA stocks are finer-grained than they were in the 1980's, plus some movies may be doing a bit of grain reduction. And of course, some movies are shot digitally today. But the main reason is that high-speed stocks have improved tremendously in the past 25 years.
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Thanks for this David. I have another totally unrelated question: I was just reading about the film Adjustment Bureau in the ASC Magazine (btw, "Friends of the ASC" has to be the best deal in the industry at just $100!) .... anyway, there were discussing a scene that I was sure was shot in a real bus, and it was actually done green screen.

My question is -- with this happening more and more -- how do you think this affects the cinematographer? (it's a huge topic, I realize) ...

Of course, I understand how it makes it a little tougher for the actor to fully get into the mood of the scene. But I think it could also be rough for the cinematographer, since so much of what is done is based on perception of the scene and interacting with surroundings.

How have you been challenged by this phenomenon, and how would you recommend young cinematographers and directors adjust to this somewhat "unnatural" process? (though I realize often more versatile and cost effective)

Thanks so much :)

Anthony
 
Hey David,

Shooting a short this weekend and have a couple lighting setups I'm unsure about.

The one scene is a party scene occurring at night. I wanted to smoke the room to add some atmosphere but unfortunately we'll only have access to a cheap fogger, no hazemakers, so I'm a bit worried about how well the fog will spread. Will of course be using a fan as well as some flags waving around. I had also intended on lighting the scene with mostly practicals but I remember you saying previously in this thread that the smoke sometimes pools above the practicals creating an odd effect. Before I get too far with this idea is there anything I can do to avoid this weird effect? Do you know any examples I can see that shows smoked interiors lit with practicals or have any other further experience with this you could share?

The second setup is simulating a darkroom. I wanted to avoid lighting with pure red light for fear of sharpness issues, so I intended on lighting with full minus green on tungsten sources. Is this a reasonable approach? Should I be doubling up two layers of full minus green to take out more of the spectrum and get closer to red? How hard is it to time the red in during post? Shooting on RedMX.

I know the best course of action would be to test, but unfortunately there's hardly the budget for it. So if you have any personal experiences with either of these situations I'd love to hear how they worked out!

Cheers!
 
AnthonyFlores said:
Thanks for this David. I have another totally unrelated question: I was just reading about the film Adjustment Bureau in the ASC Magazine (btw, "Friends of the ASC" has to be the best deal in the industry at just $100!) .... anyway, there were discussing a scene that I was sure was shot in a real bus, and it was actually done green screen.

My question is -- with this happening more and more -- how do you think this affects the cinematographer? (it's a huge topic, I realize) ...

Of course, I understand how it makes it a little tougher for the actor to fully get into the mood of the scene. But I think it could also be rough for the cinematographer, since so much of what is done is based on perception of the scene and interacting with surroundings.

How have you been challenged by this phenomenon, and how would you recommend young cinematographers and directors adjust to this somewhat "unnatural" process? (though I realize often more versatile and cost effective)
Click to expand...

Faking things on stages is nothing new, back in the 1930's and 40's, it probably would have been more unlikely to shoot on a real moving bus. Of course, with rear projection at least everyone had a sense of what was out the windows.

It takes a lot of imagination, that's for sure, to create all effect of being on a moving bus while parked. Hopefully the plates have already been shot so you know if you are matching to sunny or overcast footage. The main problem is that if you do it wrong, it looks weird, but you are also at the mercy of the compositor as well.

Actors have a strong healthy imagination, after all, they are not playing themselves, they are playing fictional characters in fictional situations... so dealing with a missing background is not the hardest thing in the world, even if they were on a real moving vehicle, let's say a process trailer rig, they wouldn't actually be driving and they'd see crew and equipment out the windows anyway, so in some ways a greenscreen environment may actually be less distracting than real traffic problems with crew people on trailers, traffic police on motorcycles, the director giving instructions over a walkie, having to slate their own shots, etc. And imagine a period movie where you are surrounded by a mix of period locations and modern filmmaking equipment.

It's harder when the greenscreen will be replaced by specific things that they have to act to (like King Kong or a dinosaur about to attack them) versus a general background.

But there is definitely an issue with not having a real location to respond to, for everyone involved.
 
Patrick Kaplin said:
The one scene is a party scene occurring at night. I wanted to smoke the room to add some atmosphere but unfortunately we'll only have access to a cheap fogger, no hazemakers, so I'm a bit worried about how well the fog will spread. Will of course be using a fan as well as some flags waving around. I had also intended on lighting the scene with mostly practicals but I remember you saying previously in this thread that the smoke sometimes pools above the practicals creating an odd effect. Before I get too far with this idea is there anything I can do to avoid this weird effect? Do you know any examples I can see that shows smoked interiors lit with practicals or have any other further experience with this you could share?

The second setup is simulating a darkroom. I wanted to avoid lighting with pure red light for fear of sharpness issues, so I intended on lighting with full minus green on tungsten sources. Is this a reasonable approach? Should I be doubling up two layers of full minus green to take out more of the spectrum and get closer to red? How hard is it to time the red in during post? Shooting on RedMX.

I know the best course of action would be to test, but unfortunately there's hardly the budget for it. So if you have any personal experiences with either of these situations I'd love to hear how they worked out!

Cheers!
Click to expand...

You should seal the room from drafts, smoke it up, wave it around, and wait for it to spread and settle. For a party scene where people in theory might be smoking (even if you don't see that), like a bar scene, a little bit of drifting smoke won't kill you. You can look at smoked night interiors in movies like "Blade Runner" or some Peter Hyam movies of the 1980's.

You'd definitely want to double or triple up on the Full Minus Green, otherwise it's just a pale pinkish effect. Underexpose a little bit or else the colored lighting will get washed out. I haven't done this myself so I can't tell you any specifics, but it shouldn't be hard to time a heavy magenta image into a red image.
 
If I may i would like to pick your brain on the specifics of working with anamorphics.. Namely controlling the anamorphic flare..

One project I was watching, every practicle and source seemed to create an intense anamorphic flare.

Another project I saw had loads of practicles and large sweeping bright sources.. Yet it was only the large sources that seemed to create a very slight yet intense anamorphic flare (relative to the size of the source).. The bright practicles had absolutely no flare at all..

So my question to you is how does one gain control over this? Can it be controlled with diffusion and exposure? The main element I can attribute to the difference between the two is the later project had a much softer diffuse feel..

Will a 10k with FullGrid have less intense anamorphic flare as plain Fresnel or even openface? How is this further affected with atmospheric and Lens Diffusion?

How does this all even further change with exposure? Is there an anamorphic flare "threshold" when setting exposure from the spot meter? Aka at X stops over the practicle will start to flare?

I know the Lens' sensitivity to Anamorphic Flare artifacts fits into the mix as well, but say i need a sensitive lens and want to control flare in everything except one element that i need to flare strongly.

Cheers
 
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The flares are mostly determined by the brightness of the source in the frame plus the sensitivity of the lens to be flared -- only testing can determine that, but you basically have to be able to control the brightness of lamps in the frame if you don't want them to flare.
 
Just finished Day 1. Smoking the set looked great. Barely had to use any fill at all. Consistency was quite difficult though.

Ended up using 4 layers of full minus green at half a stop under for the darkroom scene. Worked wonderfully! Everything looked sharp for resolution and the rest of the timing for the red was very easy to do.

Many thanks for the advice!
 
Hey David! This question has been plaguing my mind for some time now and I can't seem to find an answer to it anywhere...so here it is.

Understanding that aperture changes the amount of light let into the camera, why doesn't changing the aperture change the overall FOV?

Thinking about the way the iris works, it would seem to me that opening and closing your iris would change the size of the light beam hitting the sensor, thus making your image "crop." Thanks in advance!
 
I hope David doesn't mind if I chime in on this one. You're under a slight misconception of how the optics of a lens work. If you point your camera at an object the light emitting from one single point on this object will hit the full front surface of the lens after which each 'beam' will take a different path through the barrel of the lens, depending on where it hit the front element. After leaving the lens all the beams will converge again into a single point on the film plane (assuming that the focus is on the object). Closing down the iris will thus gradually eliminate beams that run along the periphery of the lens. Regardless of where an object sits in the frame the mechanics are the same. For every object there will always be some beams running through the center of the lens and others that are closer to the periphery. This is also why most lenses are sharpest if stopped down a few stops.

Hope that helped.
 
Take a look at these diagrams:
http://homepage.mac.com/cbakken/obookshelf/camera.html

I know it's a bit confusing because I have a hard time describing it myself, but essentially each traveling light ray isn't a "pixel" of one part of the image so that cutting off a light ray means cutting off part of the image. The whole image can travel through a narrow aperture, hence how pinhole cameras work, but larger apertures allow more light to pass through including uncollimated (out of focus) rays, hence why there is less depth of field as the aperture gets bigger.
 
Reinhold and David, thank you so much for your responses! It has always "made sense" to me in the instance that the larger your aperture the more uncollimated light rays pass through. My main zone of confusion (pun intended) comes with how large the breadth of the light coming into the camera hits the film or sensor. My main assumption, at this point is that the smaller your aperture the larger the angle of transfer (not sure what to call it) the light has when coming in, thus allowing for the same FOV when it hits the film or sensor. Is this assumption incorrect? I can make graphic models if that helps to explain... Thanks again!
 
David Mullen ASC said:
I know it's a bit confusing because I have a hard time describing it myself, but essentially each traveling light ray isn't a "pixel" of one part of the image so that cutting off a light ray means cutting off part of the image. The whole image can travel through a narrow aperture, hence how pinhole cameras work, but larger apertures allow more light to pass through including uncollimated (out of focus) rays, hence why there is less depth of field as the aperture gets bigger.
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Uhm, that right there is probably the most clear and succinct way I have ever heard or read it explained, and I am just a post production cave dweller who doesn't get out in the field much, let alone swap a lens or spark a light. I have always known what's happening but that kind of cleared up a bunch of the fuzzy parts in my understanding. Thanks Mr. Mullen
 
Dear Mr Mullen,

I already had a conversation with you concerning a low budget feature film, Super 16, and digital acquisitions. As I finally finished the script I will go into some kind of preproduction, talk with people (especially dp, cg artists etc), make calculations, budgets, etc... My question is: most of my movie takes place in a dark and empty city which represents an alternate world in the movie, (and only the framing of the story, the beginning and the end takes place in the "real world" in orange sunlight)... I imagined a bluish color tone for the dark city, like the bluish tone of ALIENS (1986). I have to choose between Super 16 or some kind of digital acquisition. Super 16 is closer to me, because it is film.... Previously in our conversation here at reduser.com, you advised me to shoot on RED beacuse of the low light situations. However, since then, I figured out, because of the low budget nature of the production and the intended bluish look, it would be a good idea to shoot the dark and empty city in day-for-night. So I could shoot the city without any city lights, it would look like an abandoned town, and with CG and matte painting we would modify and enhance it. In this case what would you say? Super 16, or digital (personally I am not into the "Red look", but liked the Arri Alexa material I saw, however that's an expensive camera (but maybe I can get a deal for that...). So what would you advise?

And what solutions could you advise me for archiving the material in case I shoot digitally? In case of S16 its obvious... Put the shot material in the cans in a basement or some safe place, and that's it. But how I archive all the footage for the long term in case of digital in this low budget production? I read may times that the archiving is the greatest problem for the digital productions. Somewhere on a conference it was said, that our grand children will more probably be able to watch a movie from the 1920s, then for example a digitally shot feautre from last year.... (I'm not talking of the Social Network, or Avatar sized movies, but the small films...).

Thank you,
Gabor D.
 
Frame rates and gravity?

Frame rates and gravity?

If anyone on here might know, I'm hoping it will be you David...

What is the formula to calculate the correct frame rate to simulate a reduced gravity environment... like say, on the moon?

I know there is a formula for calculating the correct frame rate when shooting miniatures that will create the feeling that these objects have greater mass than they do. Since mass is a function of gravity, there must be a similar way to calculate frame rates for reduced gravity situations (by decreasing the acceleration of gravity).

Many thanks for your very valuable contributions to this forum.

Best,

Todd
 
Hi David
I have a couple more questions to ask about your working methods on features.
Do you storyboards, either in pre-production or on set?
Do you ever shoot calibration tools like greyscales?
Thanks in advance for any info.
regards
Nigel
 
Gabor:

It's more complicated than just sticking your cans of negative in the garage... to be archival, you'd have all your film elements in a climate-controlled vault, and you'd have a protection copy of the cut negative (not all the uncut negative though), usually that's an interpositive, but to be really anal-retentive, you'd have b&w fine-grain separations as

(I hate the internet connection in my hotel room, I keep having to turn off and on the wifi to get it to stay connected, and it is so slow that it chokes on half my posts and emails, I can't send any photos to anyone, and have the time, I have to drive to a Starbucks and work out of there... I've been here a week and have been begging to be moved to another hotel.)

so the rest of my reply was lost but it basically said that the solution to digital archiving is data migration, regular copying of data every several years, and multiple copies stored in multiple locations, etc.
 
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Gravity is a function of mass, not the other way around -- an object's mass is not determined by the degree of gravity acting on it, only its weight is affected by gravity. Which is why if you jumped off of a cliff on the Moon, you may fall 6X slower, but you're still going to hit the ground pretty hard because of your mass. Same goes if you throw a bowling ball at someone on the Moon, it may be easier to throw farther, but the damage it does when it hits due to its mass + energy is still the same more or less.

Anyway, the problem is that even if you sped-up the camera by 6X to simulate how fast an object falls on the Moon, people on the Moon don't move at 1/6th their normal speed, so just shooting everything in extreme slow-motion is just going to look like what it is, slow-motion not less gravity. Which is one reason why for "From the Earth to the Moon" they tied helium balloons to the actors playing astronauts on the Moon, to increase their lift when they bounced/walked without resorting to extreme slow-motion. However, you do probably need some slow-motion just get the falling dust to fall more slowly, and probably you would have the actors walk/move faster to compensate. So it's basically a mix of techniques and you just have to test and eyeball it until it looks right.

Even with the speeds recommended for miniatures, you have to remember that this is only necessary when the object interacts with things that have their own speed, like falling dust, water, moving clothing, etc. A miniature spaceship with no moving parts passing by the camera does not have to be shot at high-speed, in fact, usually they are shot at a low-speed in order to stop down the lens and increase depth of field.
 
Thanks Mr Mullen! I just wanted to point out the difference between storing digital files versus film negative... I oversimplified it.

What you think about the first part of my question? In the described circumstances, DFN would be better with S16 or digital? And one more question... Although I'd like to get a blueish look, I would like other colors to remain in the scenes too. How much control over the colors will I have in case of DFN with a very good DP and a very high skilled colorist and with a DI route?

Many thanks
 
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