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How to use my lightmeter with DV or HDV?


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#1 Jacqueline Donaldson

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Posted 23 August 2006 - 06:21 AM

Hi,

I shoot alot on DV and just started to use HDV - I usually light to the f-stop I want depending on what depth of field I want etc...I'll then usually eyeball it until I'm happy, but I'd like to start using my lightmeter for several reasons, to be more acurate in my lighting, to gain a better working knowledge of my meter and start to build up more complex lighting skills. My question is, what setting do I use the meter at with video? I assume that the shutter angle remains at 180 degrees, what about the shutter speed, I recently shot on a Sony ZP1 HDV (PAL) and used the cineframe 25 function - we all know it's not true progressive, so I'm a bit confused about what I should set my meter to? And Lastly what ISO/ASA setting do I use??

Thanks
Jacqueline
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#2 Matthew W. Phillips

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Posted 23 August 2006 - 06:55 AM

Hi,

I shoot alot on DV and just started to use HDV - I usually light to the f-stop I want depending on what depth of field I want etc...I'll then usually eyeball it until I'm happy, but I'd like to start using my lightmeter for several reasons, to be more acurate in my lighting, to gain a better working knowledge of my meter and start to build up more complex lighting skills. My question is, what setting do I use the meter at with video? I assume that the shutter angle remains at 180 degrees, what about the shutter speed, I recently shot on a Sony ZP1 HDV (PAL) and used the cineframe 25 function - we all know it's not true progressive, so I'm a bit confused about what I should set my meter to? And Lastly what ISO/ASA setting do I use??

Thanks
Jacqueline


The first thing to realize about your endeavor is that a video CCD doesn't respond to light in the same manner in which film does. Video is much more sensitive to light than film, save maybe the really fast films. Also, the Cineframe bit will make things difficult too because you arent really recording progressive so your calculations from film won't be accurate. Also, it is not documented what your ASA/ISO or even DIN ratings are. This will make it pratically impossible to use a light meter effectively. To be honest, I haven't known anyone to get too good of results using a light meter for video. I think you would be better off with a nice external monitor with full frame.
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#3 John-Erling Holmenes Fredriksen

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Posted 23 August 2006 - 08:11 AM

I guess an easy way to get practice using your lightmeter would be to take a film still camera and use your light meter to determine exposure. I shoot a lot of slides myself, and use my light meter with some of my old "manual" lenses.

As for using light meter with video, there are ways to determine the parameters you need to do it. I can't say if it's practical or accurate or at all recommendable, but take a look.
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#4 rajavel

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Posted 23 August 2006 - 08:59 AM

hi this might help....

Faking It: Metering Light to Get the Film Look in Video
Digital video doesn?t have to look amateurish. Learn how to measure light like the pros.

By Peter Bohush


The Sekonic L-608Cine Super Zoom Meter.
--------------------------------------------------------------------------------

If you?re trying to create the look of film with digital video, setting the proper light levels is critical to creating the balance of light, shadow, and contrast that film provides. The DV cinematographer benefits from following film lighting techniques and using a light meter to measure the quality of light being recorded.

With film, lighting is measured according to the speed of the film itself. The lens and light work together to bring the appropriate image onto the film?s emulsion. With video, the videotape itself has no light or speed rating. It?s the camera which controls how light is recorded by the CCDs onto the tape.

Light meters are read according to settings based on the speed of the film being used. For example, a cinematographer can point a meter and know how the light going to the camera will reproduce on film because the meter reads F4 and is set to the film?s speed of 200 ISO. To use a light meter in video, you have to know the camcorder?s speed rating (measured in lux) and calculate that to an ISO (formerly called ASA) film speed rating.

According to Tom Musto, a well-known lighting instructor and DP/director based in Wilkes-Barre, Pennsylvania, "The best way to achieve a film look is to set your lighting and ratios using a meter. Then you?ll know that the ratios will be right no matter what the setting of the camera." Musto offers lighting classes around the country; more information is available at http://www.videolightingclass.com/.

Most professional video camcorders have published lux ratings, so it?s easy to calibrate light meters. Popular prosumer digital video models often don?t, however.

"Using the smaller cameras with a light meter is tough, because some of the F-stop settings on the palm-size cameras do not coincide with F-stop settings on larger cameras and meters," said Musto. "Basically, some DV cameras have their own F-stop systems which are not consistent with the rest of the world."

The work-around is to calibrate your light meter to your camcorder. This involves lighting a gray card and setting your meter to match the F-stop reading from your camcorder, as follows:

1. Purchase an 18 percent gray card, manufactured by Kodak and available online or at most photography stores.

2. Light the gray card with a flat light (no shadows.) Take an F-stop reading from your camcorder?s built-in meter. Make sure that the exposure is set to 0 dB gain.

3. Using the camcorder?s F-stop as a reference, set your light meter so it reads the same F-stop at 1/60th second, or 30 fps.

4. Note the meter?s ISO reading. This becomes your camcorder?s ISO number.

5. To use your light meter on your shoot, lock it to the camcorder?s ISO number and take readings relative to that setting.

When lighting for digital video, a contrast range of about 4-to-1 (two F-stops either above or below the key light level) will yield accpetable video picture.

Musto achieves a film look by keying his subjects at F4 or F5.6 and lighting the shadows to fall within his two stop limits. "If my key light reads 5.6, that is the highlight," said Musto. "The shadow should read F2.8 to be two stops darker. Always begin with the desired highlight reading and work your ratio with the shadow area."

Of course, Musto and other DP?s stress that one can?t simply light by mathematics. Personal style and the requirements of the project are the starting points for lighting any scene. But following standard lighting rules and ensuring the light falls within acceptable ranges using a light meter are the basics upon which artistry in lighting is built.


....this is an article i found sometime back....chek it out!

cheers
rajavel
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#5 Jacqueline Donaldson

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Posted 24 August 2006 - 07:06 AM

Thanks guys
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#6 Rupe Whiteman

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Posted 24 August 2006 - 09:52 AM

Hi,

I shoot alot on DV and just started to use HDV - I usually light to the f-stop I want depending on what depth of field I want etc...I'll then usually eyeball it until I'm happy, but I'd like to start using my lightmeter for several reasons, to be more acurate in my lighting, to gain a better working knowledge of my meter and start to build up more complex lighting skills. My question is, what setting do I use the meter at with video? I assume that the shutter angle remains at 180 degrees, what about the shutter speed, I recently shot on a Sony ZP1 HDV (PAL) and used the cineframe 25 function - we all know it's not true progressive, so I'm a bit confused about what I should set my meter to? And Lastly what ISO/ASA setting do I use??

Thanks
Jacqueline


... I think the z1 has a nominal asa equivalent to 300 in the tungsten setting. An easy way to start is to zoom your camera into a grey card (under tungsten light and camera preset to start) and set the camera to auto and get an exposure reading. Then use your incident meter to get a reading to the camera from the same position as the grey card. You can then tune your light meter to match the camera's reading - this will then give you the asa speed of the camera. You can then do the same under daylght conditions to work out the asa setting in daylight - normally about 2/3 to 1 stop slower than the tungsten setting....

Hope this helps,

Rupe Whiteman
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#7 Michael Morlan

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Posted 24 August 2006 - 10:01 AM

... I think the z1 has a nominal asa equivalent to 300 in the tungsten setting.


Actually I metered the Z1U at 125ASA with all menu settings at factory defaults:

tools:
grey card
Sekonic L-558c spot reading center of card

testing method:
o lit grey card for most even light
o used camera's auto iris to establish an exposure
o metered the card with the spotmeter and adjusted speed until f-stop matched

Note that the equivalent ASA of a video camera will change as you manipulate settings like gamma, setup, pedestal, etc. Be sure to meter your camera after you have settled on your camera's look.

All the HDV cameras are fairly slow (around 125ASA range) due to their cramming so many pixel elements into such a small chip.
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rebotnix Technologies

Ritter Battery

Willys Widgets

Tai Audio

Technodolly

Glidecam

CineTape

Paralinx LLC

Media Blackout - Custom Cables and AKS

Gamma Ray Digital Inc

The Slider

Aerial Filmworks

Wooden Camera

CineLab

Metropolis Post

Rig Wheels Passport

Abel Cine

FJS International, LLC

Broadcast Solutions Inc

Visual Products

Opal