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-   -   Why is my footage so noisy? - Answer (https://www.dvinfo.net/forum/photon-management/142466-why-my-footage-so-noisy-answer.html)

Perrone Ford January 26th, 2009 06:30 PM

Why is my footage so noisy? - Answer
 
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One of the often asked questions from shooters is why their footage is so noisy. They have the latest and greatest camera, they set the parameters according to what they saw on the internet, and yet the blacks are not clean, and there is grain throughout the footage. It's a maddening issue. The sage posters generally ask how much light was on the subject but generally get vague answers from the original posters. Comments like "plenty", "a lot", or "500 watts" are common.

So if you'll permit me, I'd like to address this just a bit. Roger Deakins is one of my favorite Cinematographers and has shot some of the most beautiful footage ever commited to film stock. He is known best for his lifelike lighting that does not interfere with the story. The January edition of American Cinematographer offers a unique look into some of the lighting setups he used in Revolutionary Road, and I highly recommend you pick up a copy. Page 32 of the magazine is particularly helpful and I'd like to point out a few things.

The first image on the page shows how Deakins set about trying to get "daylight" into the house they were shooting in. Large reflectors with very large sources bounced off them and into the house set up ambient lighting levels. It's probably fair to say that ambient in the house would be about what you'd see on a bright, but partly cloudy day.

The second photo shows what the scene lighting in the house produced. Nicely lit, not overly bright, even toned with nice shadows and little noise.

But it's the third photo that really tells the tale. In addition to the 18k lights on the lawn providing ample ambient in the house to shoot existing light, Deakins has added 3 400-600w fixtures bounced into a reflector at fairly close range. Let's examine what that means.

He is shooting with Kodak 5218. An iso500 film typically rated at 400. My EX1 rates at about 320-400 when shooting 1080/24p. Most 1/3" sensor cameras would probably rate closer to 160-200. He is using some of the best lenses in the world which allow more light than our cameras could hope for, and he has a 35mm "sensor" which is about 10 times the size of what we typically shoot on. In other words he is gathering in TONS more light than the average video shooter. And even with all that, he is putting several hundred footcandles of light on this 2-shot in addition to the ambient light pouring in.

To get a similar amount of light in my camera, I'd have to shoot with something akin to 3-4k watts of tungsten power in what looks to be a 10x12 sized space. He has carefully flagged off the lights to avoid spill, and flagged off the top of the scene to avoid too much light directly on the actor's faces.

And with all this, the image comes out cleanly.

So the next time you take out your camera with the intent of shooting clean footage like you see in the Hollywood movies, take a page from the script of one of the worlds best cinematographers, and put ample light on the subject. And leave the "existing light" shooting to the guys with the $250k cameras.


As usual, just my $.02 and I hope it helps someone.

Dan Brockett January 26th, 2009 08:04 PM

Good post Perrone.

Very true. One of my favorite shows that I worked on that had great lighting was NYPD Blue. One of the numerous DPs that worked a few seasons, Stephen Crawford, used to light the entire precinct with numerous 12 and 18ks through all of the windows in the multi-story set. He could have lit it like a normal TV show, from a grid but he wanted that naturalistic "Deakins-like" look to it. Plus with all of the multiple roaming cameras, putting all of the light sources outside of windows, other than practicals or perhaps an occasional hero light on set, meant that they didn't have to constantly worry about blocking to not show stands, cables, rigging or sources.

If you watch that show, you can also see that they liked to shoot up from the floor as well as down onto characters.

I don't think many prosumer camcorder owners have a clue as to how much lighting it takes to achieve a really killer, naturalistic look that most of them are trying to achieve. A Lowel kit just isn't going to get them there. You see the same posts over and over, "I am just starting out, I bought XYZ camera and I have $800.00 left for a lighting kit. I need to shoot a scene with eight people around a dinner table. Will this Britek or will a couple of Home Depot worklights do it?".

Usually the largest scenes I light may have 4-5 actors in them and just for small intimate scenes, I am working anywhere from 4-10 instruments and that is definitely not to light up the whole set, just portions of it. And that is largely because I don't have anything larger than a 2k.

Dan

Perrone Ford January 26th, 2009 08:23 PM

Dan,

That's the difference. You know that to have anything larger than a 2k, you'd need a generator. Oddly enough, my largest light is Mole 2k. :)

There is nothing wrong with not putting 500FC on a scene. Non-Pro actors are going to have terrible stage fright walking onto a set that looks like a summer day at the beach! But we need to understand what we're doing. I tend to shoot at F4 or more open. I also shoot with my camera's lowest gain setting, -3db. BUT, I also take care to have enough light on the set to nearly force me to have to use ND filters. If you don't have adequate light to have you looking at ND, you are probably not shooting with enough light to get those blacks out of noisy places.

Your comments about people buying cameras and such and having $800 left over for lights (and grip, and audio) are SO true. Many, if not most, could have saved a fortune on the camera if they'd have simply bought some decent lights and an audio recorder and mic. When I decided to take my office HD, I budgeted $3k for lights (mostly interviews), $2k for the sound, and whatever I had left over for the camera. Fortunately, I had enough for the EX1 still. But I did NOT have enough left over for media for the camera! OOOPS! I had to film in HDV with my firestore. Until the SDHC thing happened.

I hate noisy footage. If I want noise, I want to add it myself. I wish every person who graduated to the prosumer stage had a mandate to buy a barger baglite, a 2k, and a 1k softbox. Along with 5 c-stands and foamcore. If that was the mandate, I bet we'd see a LOT less posts about noisy footage with 1/3" CCD cameras.

Shaun Roemich January 29th, 2009 11:04 AM

Perrone: I own 4 800w Ianiro's, a Lowel 55 Rifa EX (500w), and 5 Lowel Prolights with 250w lamps and I consider that a good START.

BTW, that's about $10k in lights, stands and accessories.

Eric Stemen February 3rd, 2009 08:39 PM

Great post Perrone and Dan. When I bought my first prosumer camcorder I had no idea about lighting(I just shot BMX videos) and it stayed that way for probably 3 or 4 years until I got a DSLR with a wireless flash. Once I started using an off camera flash I noticed that some of the photos really turned out great but I had no real idea how to place the lights. After working at the college PBS station for a year and a half I've learned that the way you place a light really makes a difference. I'm not great at lighting but I'm way better than I used to be.

It's not just the number of lights, but they way they are placed.

You said pretty much the same thing in your post, but just thought I would share my experience.

Dan Brockett February 3rd, 2009 09:38 PM

Thanks for your input Eric. You should spread the word. I see a slightly disturbing trend developing amongst 5D MKII users that I think bears some comment. Yes, the 5D MKII is capable of fairly clean images with the camera set as high as ISO 6400. But even with that camera, if you want your shots to look GREAT, you still need to light. Just because a camera can see a lot without light doesn't mean that people should just forsake lighting and only shoot available light. I have seen some nice images with that camera but mostly they were lit or at least partially lit shots that impressed me.

Being a good photographer/videographer/cinematographer is all about taming light and bending it to your will. You paint with the light to highlight objects and talent and too turn that flat 2D format into a 3D reality. There is no substitute for using light.

Dan

Mark Stavar February 26th, 2009 04:59 AM

Just wanted to say that I have found this post to be hugely informative.

Just did my first shoot last weekend where i was responsible for the lighting -- baptism by fire. Wish i had read this thread before then. Never mind.

Amazing how much thought and tech goes into making something look like it is totally spontaneous and natural!

Thanks all for sharing your experience and wisdom.

marks

Subbu Vedula February 26th, 2009 08:14 AM

about to ask a question and saw your post.
 
Thanks Perrone. Your post helps newbies like me. I was using existing one lamp to create dark mood and it was noisy. Afterall the lens (my DVX's) is not as sophisticated as my eye is. I have a question though. If I light the subject with ample lighting and close down the aperture good bit (to make the room look darker), does it still add noise?

Ken Campbell February 26th, 2009 01:45 PM

So, I just spent $250 on a 1/6" single sensored videocamera and have $50 left over for a light kit...

Seriously though, I just wanted to thank the great posters here who continue to educate budding videographers on the importance of lighting (and sound for that matter). As a result, I've learned so much about the technical part of videography so fast. Your posts are really appreciated!

Marcus Marchesseault February 26th, 2009 02:55 PM

Subbu (and others), noise is caused by the camera increasing gain (aka "iso" in still photography) which induces noise exactly like turning up the volume on a weak audio signal. The inherent noise generated by electronic circuits starts to become stronger compared to the weak video image. All electronic circuits are subject to noise from their own and outside radiation inducing currents within their own "wiring". You might think that digital equipment would not be subject to this effect since it is not analog but at the point where the real world and the digital meet there is always a physical medium. In the case of audio it is the microphone and signal amplifier. With video it is the CCD or CMOS imaging chip behind the lens.

If you can decrease the gain in your camera separately from the exposure, turn down the gain and add light until the image is to your liking. Making the image seem dark has nothing to do with the strength of the light but rather with the difference between lights and shadows in your image. Also, an easy rule to follow is to not light your talent from the front but from the side and leave lots of shadows on their faces. Also, make sure there are some dark areas in the background. Just light the edges of your talent and you will see that it seems like darkness while still retaining an image of your scene.

To combat signal noise there are a few options in no particular order:

Increase the signal strength. With audio that requires moving the microphone closer or talking louder. In video it means more light is needed.

Use more sensitive signal-gathering equipment. Video cameras with larger chips and better lenses gather more available light. High quality mics have better diaphragms that provide the amplifier with a stronger signal.

Use equipment that has less inherent noise. Better imaging chips and microphones/amplifiers generate less noise so the incoming signal can be increased without getting fuzzy. This is why better mics/amplifiers are quieter and better cameras with the same size chips can be less noisy at the same light levels.

Equipment with less noise and greater sensitivity tends to go together into much more expensive gear. It is often more cost effective to just use more light than to get a more expensive camera. Even the best cameras still need light so you can't avoid depending on the skill of the lighting people. Since the sun is free, reflectors are great for lower budget lighting. If you have plenty of electricity available, cheap work lights are also cost effective. Of course, depending on the sun can be risky and work lights have limitations that make them not worth the cost savings once larger crews and expensive talent become part of your productions. In the real world, a balance of available light and controlled lighting is likely the best choice in many situations due to cost. The talent of the lighting crew is where the best quality with available lighting is brought to the camera. This makes the lighting and camera crew (not the camera and lights) the most important component of getting a good image.

Subbu Vedula February 26th, 2009 03:14 PM

Thank You
 
Marcus, thank you very much for taking time to explain it in detail.
I really appreciate.


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