Light Meter

L

Loren Simons

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Why are light meters necessary? Is it just so you can light without the subject there? or is there some other use?
 
I still don't really agree with that article. The main thing that he's talking about there is not stepping out of the dynamic range of your digital camera, something that IS very important, I don't disagree with that.

The only thing he doesn't mention is what the dynamic range of your camera really is and how to find that out. You can do tests with a waveform monitor to see how many stops of lattitude your camera has, but why not just use the waveform monitor in production as well? It's going to be MUCH more accurate, as it's actually looking at the image and plotting out the luminance values, while with a light meter you're sort of doing it indirectly.

So...just get something that can allow you to look at your picture with a waveform monitor. Then from there you can look at the scene and see if you're clipping any highlights or shadows, and then change the light accordingly.

One thing that a light meter IS good for though is keeping the ratios of your scene consistent while you're shooting it. Anything else is just sorta...eh.
 
RyanT said:
I still don't really agree with that article. The main thing that he's talking about there is not stepping out of the dynamic range of your digital camera, something that IS very important, I don't disagree with that.

The only thing he doesn't mention is what the dynamic range of your camera really is and how to find that out. You can do tests with a waveform monitor to see how many stops of lattitude your camera has, but why not just use the waveform monitor in production as well? It's going to be MUCH more accurate, as it's actually looking at the image and plotting out the luminance values, while with a light meter you're sort of doing it indirectly.

So...just get something that can allow you to look at your picture with a waveform monitor. Then from there you can look at the scene and see if you're clipping any highlights or shadows, and then change the light accordingly.

One thing that a light meter IS good for though is keeping the ratios of your scene consistent while you're shooting it. Anything else is just sorta...eh.
Click to expand...

A waveform is very good to use, but I find the light meter does allow more precision when not dealing with the big picture. Ratios, small objects, etc. Sometimes reading a waveform can get tough if there is lots of information and you are trying to tell one object from another.

Waveform is a very good tool, using both would not have any negatives.
 
A waveform does not give you a lot of information that can be helpful.

eg Ratio of back light to front light, Ratio of Key to fill, Ratio of shadow to highlight, ratio of subject to bg etc.........


A meter will also allow you to light a set/subject/.bg etc with out the camera being present.
 
Yeah, don't get me wrong guys. There's no better way to figure out ratio's than with your light meter, it's where the waveform falls short for sure. It will also allow you to light without the camera being around, which is very handy when you're moving quick.

I hadn't really had too many issues with reading luminance values of small objects, but I can see where that can come in handy. Like Ryan said, using both wouldn't have any negatives and in the end you will get yourself very very close if not all the way there with just your waveform.

I'm just trying to give you guys another viewpoint is all. I've watched so many awesome DP's work, some of them even ASC, and none of them ever pulled out a meter while shooting digitally. Not to say that it's wrong to do so, but people are getting by just fine without one.

As for you Hans....I know what you are, but what am I? Hmph!
 
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I use the light meter to speed up production and minimize risk in the above mentioned areas (range and ratio). I set it up for skin tones (faces). The number one point being that I don't want a blowout on a face (unless intended). Using it also makes it much faster and more to the point than trying to tune the camera every time. Also, the less equipment, the less people, the lower the cost.

I have this small list (sequence) of things to do before recording and as far as the light meter is concerned, I don't even switch the camera on before I have not made sure the set is suitably lit. So I would quickly do readings in the center (center of focus - as far as composition is concerned - where the talent will be). Using the F.Stop reading, I know immediately if we need more or less light (determined by the DOF required). I then check the background ad also the ratio (key and fill). Now I know if the lighting is suitable for the camera. I wasted no time trying to look at a picture (which is really not accurate). I also have my light meter tuned to the ND filters in the camera, so if I go outside, I would know which ND filter to use based on the light meter reading.

Once readings and adjustments were done, I simply switch on the camera make the settings according to the light meter and I'm ready to shoot, knowing that my most important subject (the talent) will be very accurate as far as lighting.

I see a light meter as a tool to simplify your setup, speed things up, remove guess work and risk.

I also have my WB cards attached to the light meter and they are always packed with the camera.
 
You guys should check out the new scopes from leader. It covers all the short comings of a regular wafeform. With it's cine modes you view a "predator" like image that allows you to luminance and ratios along side a histogram and a regular waveform. That function allows for even the untrained eye to make quick calls on lighting. In the hands of a pro it's extremely powerfull.

That said, I still have a light meter in hand because I dont like to walk back to the DIT tent everytime I want look at the picture. I do all I have to do with the meter and spot check my work with the DIT either in the tent or over the radio.

PS: Unless you have a very good working relation with your DIT as I do, never disscuss anything over the radio. Just walk over to the tent.
 
peetdevos said:
I use the light meter to speed up production and minimize risk in the above mentioned areas (range and ratio). I set it up for skin tones (faces). The number one point being that I don't want a blowout on a face (unless intended). Using it also makes it much faster and more to the point than trying to tune the camera every time. Also, the less equipment, the less people, the lower the cost.

I have this small list (sequence) of things to do before recording and as far as the light meter is concerned, I don't even switch the camera on before I have not made sure the set is suitably lit. So I would quickly do readings in the center (center of focus - as far as composition is concerned - where the talent will be). Using the F.Stop reading, I know immediately if we need more or less light (determined by the DOF required). I then check the background ad also the ratio (key and fill). Now I know if the lighting is suitable for the camera. I wasted no time trying to look at a picture (which is really not accurate). I also have my light meter tuned to the ND filters in the camera, so if I go outside, I would know which ND filter to use based on the light meter reading.

Once readings and adjustments were done, I simply switch on the camera make the settings according to the light meter and I'm ready to shoot, knowing that my most important subject (the talent) will be very accurate as far as lighting.

I see a light meter as a tool to simplify your setup, speed things up, remove guess work and risk.

I also have my WB cards attached to the light meter and they are always packed with the camera.
Click to expand...

Which meter and WB cards do you use please provide a link...
 
Shooter said:
A waveform does not give you a lot of information that can be helpful.
Click to expand...
Au contraire, the waveform really actually does give you more information... because it tells you what the camera is actually doing with the light you're giving it.

eg Ratio of back light to front light, Ratio of Key to fill, Ratio of shadow to highlight, ratio of subject to bg etc.........
Click to expand...
See, here's the thing -- while a light meter can tell you what those ratios are, it cannot tell you what the camera will DO to those ratios. So it's fine and dandy to use a light meter if you've got a flat linear output from your sensor, but... in what camera does that happen? None? You've always got some processing, and the results you'd get from standard gamma are *very* different than the results you'd get from cinelike-D, yet the lighting would be identical.

The waveform would show you what you're actually getting.

A meter will also allow you to light a set/subject/.bg etc with out the camera being present.
Click to expand...
Yes, but not accurately. You can light mathematically with a light meter, but it may have little bearing on what the camera actually does with the image it's fed, and you may end up having to adjust everything based on the actual output of the camera's signal processing.

Maybe I'd phrase it more like: "if all you care about is the light, a light meter is fine; but if what you care about is the final image, a waveform monitor is far more valuable."

* this of course applies basically when you as cinematographer do not have an intimate familiarity with the exact exposure characteristics of the exact settings you're working with. If you've done extensive profiling and know exactly how the camera responds under the exact settings you're working with, then the light meter becomes all the more practical as a standalone product. Or, if you're using a profiling meter such as the L-758C, which takes gamma and other processing into account, then the light meter becomes more useful as a standalone tool.
 
Barry_Green said:
Au contraire, the waveform really actually does give you more information... because it tells you what the camera is actually doing with the light you're giving it.


See, here's the thing -- while a light meter can tell you what those ratios are, it cannot tell you what the camera will DO to those ratios. So it's fine and dandy to use a light meter if you've got a flat linear output from your sensor, but... in what camera does that happen? None? You've always got some processing, and the results you'd get from standard gamma are *very* different than the results you'd get from cinelike-D, yet the lighting would be identical.

Click to expand...


So barry you're telling me that if I am doing a seminar event, that buying a NEBTEK
monitor with a build in Waveform monitor is a good idea to use with the HVX?
Seeing as how it can give me an accurate determination of the shots and colors?

such as this one:
http://www.bhphotovideo.com/c/product/559134-REG/Nebtek_NEB70HD_DAYLIGHT_HD_ON_CAMERA.html
 
I have a BTLH80 and love it, but the waveform is very elementry and should be used sparingly. The color reproduction on the BTLH80 very good but it's no cine-tal.
 
Sure it's not a match for a dedicated waveform monitor, and it's not even as good as the waveform in the HPX170, but -- I still find it quite useful and am glad it's there. But yeah, don't read more into it than that -- it's a minimalist waveform.
 
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