If a light meter is good enough for Deakins...

Mitch - I love being on a forum with you as we disagree on every thing!

Actually of course the gaffa pre lighting with a meter makes sense but a. Rgb histogram is a wonderful tool. Not only can one use it to ascertain exposure but also colour balance - or rather match a camera wb setting to the lights.

my fs100 was to me crippled to a large extent by the lack of rgb histo compared to the 7d I had before

using a rgb histo one can not only ascertain grey - match the three spikes on a grey card - but also shoot to a look by keeping one of the spikes a little offset eg red right to create a warm feel in camera - great use of a thin codec like the Fs or a Dslr

such an approach is far more controlled than using any form of click grey

Now. And this is why I have re entered the thread - in monitor design it is super important that a histo is reading the input signal from the camera before any lut is applied or at least that is an option.

Histos are great but Reds implementation - which is I guess where most cinamatographers met them is a total mess up as it reads after the "iso lut" has been applied and leads one not to understand the core data one is recording.

--

dennis
i spent some time at Ali chaps workshop trying to understand how to fully expose the f5 in raw mode with the minimal exposure tools - before the wfm was released.

Actually it is easy to find a true clip point of the raw file -100 zebra the lowest cine EI setting with no lut. The lowest cine EI setting is 640.. which matches your tests.

Actually I've always liked to use the minimum iso + 1 stop which gives you a stop of headroom for speculars or on set error - this would lead you to a rating of 1250 as per Sony specs. Bizarrely it would seem they got that right :)
 
morgan_moore said:
Mitch - I love being on a forum with you as we disagree on every thing!
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It's all in good fun, right?

As I said, Histograms are not particularly useful to me in the way I work. But that's the way I work. On the other hand I do find a lot of use in an RGB parade waveform. I would argue that much of what you describe above would be more precise using an RGB parade waveform than an RGB histogram. But again, that would be the way I would prefer to work.

But when you dismiss the use of an incident light meter out of hand as antiquated technology, I take issue with that. A tool is a tool. An incident light meter measures the light completely separate to what the camera does. This unburdens one from what the camera may or may not obscure or even see at any given moment. That can be useful when adjusting and controlling lights.

Histograms measure aggregate reflective light, graphing in one direction by volume and in another direction by intensity. I can see their use for stand alone images, but for a series of images which are to intercut yet have different contents within the frame I find the tool less useful. That's how I work.
 
Fun indeed.

As I said the meter is a great way of building a light design. The camera tools are best for understanding what your camera is recording. Mainly I'm recording what is there (doco) and the last thing I want is more crap dangling off me - a light meter on a string round the neck say in a factory with machines is a serious hazard.

I agree wfm can be better that a histo. Most important (but possibly off topic) is that manufacs of monitors should be providing wfm/histo before the lut is applied so one knows what one is actually recording..
 
Btw a live view rgb histo compact camera or small Dslr with and exposdisc IS an incident meter - a very good one - it is just a bunch of other stuff too. I'm not dismissing the concept of premesuring light befor the talent or heavy hard to move A camera arrives.

it would seem the gaffa could have a meter but a dop with a wider role can do better with a small Dslr whic can be a director monitor and continuity aid too..
 
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One question for light meter users.

How green is that flouro?

what is the tinted wind screen doing to the color?

What are the tinted office windows doing?

sadly the modern world is often way off the Kelvin scale in the mag-green axis..
 
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morgan_moore said:
One question for light meter users.

How green is that flouro?

what is the tinted wind screen doing to the color?

What are the tinted office windows doing?

sadly the modern world is often way off the Kelvin scale in the mag-green axis..
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Come on Sam, nobody that I have seen here advocating the use of a light meter as a filmmaking tool has said that it it the only tool that one should use for designing and setting their lighting. I am a light meter user, but I do not use it's readings as the only factor I consider when setting exposure with a video camera. There is no right or wrong here. I use a light meter because it is my standard of reference based on my film experience for evaluating the QUANTITY of lighting in a shot. I appreciate your advocacy of the use of a DSLR as tool for cinematography. I am going to try to incorporate that into my method also, but please do not dismiss my use of a light meter as my base point of reference.
 
David. I thought this was a pretty light (hearted) thread.

Being serious, of course I can see the value of a light meter for pre lighting.

Genuinely over my 20 years with images I have used them or not. Shooting strobe flash and stills on transparency a meter was critical.

Once I moved to raw stills the thing got dropped, I then moved to crappy codec motion where exposure is more critical the main problems I had with choosing a camera setting is choosing the colour settings under mixed light

As an aid to that I certainly found the rgb histo a fantastic tool on the 5d and seriously missed it on the ex1 and fs100 - my displeasure with the colours on those cemeras has now 'forced' me to move to the f3 to get a more colour flexible codec - partly to make up for the info I don't have on set.

If I was going to invest in a light analysis tool above $1000 I would certainly want it to tell me something of both temp and tint..
 
Which light meters do you guys use.

With an app in your iphone you can have a director's viewfinder.

Waveform monitor and vectroscope in camera are good tools. I don't hear anyone mentioning vectroscope here.
 
sekonic 508, thanks to a recommendation by starcentral
since I never work with big crews, I only started needing it when I first shot with the BMC, which offers only the bare minimum in terms of exposure tools
 
indiawilds said:
Which light meters do you guys use.

With an app in your iphone you can have a director's viewfinder.

Waveform monitor and vectroscope in camera are good tools. I don't hear anyone mentioning vectroscope here.
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I have a Minolta Spot F, unfortunately no longer made... I bought a Sekonic L-308DC a while back so I could read off Footcandles directly, since most movie lighting tends to give light specs in terms of such units.

I test to determine the 'effective' ISO of the meter reading and the camera reading. Usually a grey card, and in 'post' using a waveform display to determin IRE %-tage, since I don't have a 'fancy' monitor, or camera that has that 'built in'.

For me a 'vector scope' is far more from the 'video' world. I have a book on color grading, and the vector scope is used. But the alignment 'landings' to me were specifically for NTSC, or now Rec 709 HD... not necessarily for 'film'.

For that matter, I don't know what 'color bars' would benefit, given it is a 'camera generated' alignment patter... On the other hand, the various color/resolution charts are of benefit but usually quite expensive... other than the 'grey card'.
 
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I'm still using a classic Sekonic L-398. Reads directly in FC. I use it in my consulting work for measuring ambient light levels and screen illumination levels in presentation and conference room environments. Have even used it for lighting live stage shows.
I use in camera meter on my Canon zoomed in for checking spot values.

For today's low light cameras the L-398 is not sensitive enough. But for ISO speeds up to 800 it works fine. If it can't get a reading there isn't enough light to shoot by.

I mostly shoot in the 100-400 ISO range.
 
Ok so I tried a few things, to see if I can get my bearings with the light meter. I wonder if I have this right. I tried it with my GH2 and Voigtlander 25mm and it seems OK. For this test I am using incident readings at the subject, 400 ISO, shutter speed 125, and then the f stop from the meter. It seems OK and matches with the average, but is maybe a little hot.

Then I tried the same test, same lens on the AF100, ISO 400, shutter 1/60, shutter angle 180 d. It has a Cine wheel so I am looking at 24 fps, which kind of lines up with 60 shutter speed for the still camera setting. I take the reading at my subjects face, facing the camera and it says f2.8. When I set the aperture to 2.8 I'm over where I want to be. On the WFM the face is reading almost 100 IRE. I want it around 60. What works for this setup is f4. With the aperture at f4 the face is at 60 IRE, which is right

So am I not reading the meter right, or is it that yes we are at f2.8 at the face but we want the face to be two stops lower because that's what works?

My goal is not to set exposure this way but to learn how to use a light meter to light absent of the talent and without running back to the camera, and also to be able to communicate that way on set.

Anyway, thanks in advance for any help.
 
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morgan_moore said:
dennis
i spent some time at Ali chaps workshop trying to understand how to fully expose the f5 in raw mode with the minimal exposure tools - before the wfm was released.

Actually it is easy to find a true clip point of the raw file -100 zebra the lowest cine EI setting with no lut. The lowest cine EI setting is 640.. which matches your tests.

Actually I've always liked to use the minimum iso + 1 stop which gives you a stop of headroom for speculars or on set error - this would lead you to a rating of 1250 as per Sony specs. Bizarrely it would seem they got that right :)
Click to expand...

RAW is a different beast. In reality with linear gamma you really could just use a histogram or zebras just below clipping to expose for it. It is exactly like a DSLR shooting stills and pulling the image out of the highlights very easily without degrading the image or adding noise. With RAW over-exposing is "safe",, but I don't shoot RAW a lot of the time and so placement of middle grey is much more important so that more latitude can be given to the highlights, etc..

I know Alister doesn't believe my ISO rating of the F55 but others have come to the same conclusion. I will re-do my test and publish it one day so there are more facts about it... but what can I say. Really the ISO doesn't matter, it's knowing where your middle grey is transposed on the curve when using slog2, etc..


indiawilds said:
Which light meters do you guys use.
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Sekonic Zoom Master L-508.


hscully said:
Ok so I tried a few things, to see if I can get my bearings with the light meter. I wonder if I have this right. I tried it with my GH2 and Voigtlander 25mm and it seems OK. For this test I am using incident readings at the subject, 400 ISO, shutter speed 125, and then the f stop from the meter. It seems OK and matches with the average, but is maybe a little hot.

Then I tried the same test, same lens on the AF100, ISO 400, shutter 1/60, shutter angle 180 d. It has a Cine wheel so I am looking at 24 fps, which kind of lines up with 60 shutter speed for the still camera setting. I take the reading at my subjects face, facing the camera and it says f2.8. When I set the aperture to 2.8 I'm over where I want to be. On the WFM the face is reading almost 100 IRE. I want it around 60. What works for this setup is f4. With the aperture at f4 the face is at 60 IRE, which is right.
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First you need to toss the manufacturers ISO rating of the cameras out the window. (I'm serious). There are at least 4 different ways of determining a digital camera's ISO within the actual ISO standard specification in itself, so an ISO on one camera will not be the same as the ISO on another camera or necessarily match your light meter. If it is, you are lucky and that's about it.

Next you need to rate the ISO of the camera yourself by using a grey card, waveform monitor, light meter and the camera. Also 1/60th shutter is not 180d in 24fps. It's actually 1/48th shutter speed and if you light meter doesn't do 1/48th (non cine-meters probably won't) then just use 1/50th. Its not a huge variation but its nice to be as close as possible.

Rate your camera properly and try your test again. I find it hard to believe that 1 stop on your lens took your skin from 60IRE to 100IRE?



Josh Bass said:
Ok, so arguments aside. . .when is it best to use incident/vs spot metering?
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I personally work with incident measurement mode knowing the basic rules of photography. ie. if you are shooting a very bright surface or something reflective you can reduce your exposure by 1-2 stops quite easily. On the opposite end of things if you have a lot of darkness that makes up your scene you might want to open up 1-2 stops, etc.. Same with lighting shadows, if I light my skin tones with f4 and I want the background to be "black" I will light even the background 2-3 stops under my skin. This lighting the blacks let's you reduce the levels in post later and gives you clean very clean blacks. Often if shooting in the area of 800 to 1600 ISO you can use one to two Kino tubes to get the shadows lit for this.
 
morgan_moore said:
Btw a live view rgb histo compact camera or small Dslr with and exposdisc IS an incident meter - a very good one - it is just a bunch of other stuff too. I'm not dismissing the concept of premesuring light befor the talent or heavy hard to move A camera arrives.

it would seem the gaffa could have a meter but a dop with a wider role can do better with a small Dslr whic can be a director monitor and continuity aid too..
Click to expand...
Um, BTW that meter in the camera is a REFLECTIVE meter, not an incident one.
 
In my meter case:

Spectra IV (the workhorse)
Minolta F (not needed as much anymore but a perfect machine)
Minolta Color III (for matching lights in pre-light)
Gossen Panlux electronic 2 (look it up -- it's like a science lab tool. Accurate to 1/20th of one footcandle!)
Weston Master 5 (for nostalgia)
Compass
Inclinometer
Gel swatch book (mostly for use with color meter)
Gaffer glass - ND (for positioning lights and seeing when clouds will pass)
Gaffer glass - sepia (fools the eye, blinding eh cones so the rods take over and you momentarily see monochrome)

Plus I have Cine Meter on my phone, which was developed by my friend Adam Wilt after I made a comment on the CML that perhaps the iPhone's camera could be turned into a useful color meter. While he found that it couldn't be precisely profiled well enough to do this reliably, it could be used as a useful analysis tool. It's a waveform in your pocket. I have Light Meter, which is a freeish and so-so metering app, and I'm thinking about picking up a Lumu incident meter attachment for the phone, but haven't gotten around to it.

I once used the Gossen Panlux to light an entire feature and everyone thought I was nuts, or at least a mad scientist. But I had the lab print everything to my strict printer light numbers with no variation allowed, and I think the final timng session for the film had maybe half a dozen adjustments.

Of course I once shot a black & white movie where we made heavy use of colored filters and it would so mess with your mind and you exposures that in the end the only way I could consistently expose was to look through the eyepiece and dial it in, using the relative denisty of the image to land it properly. And I was bang dead on every time. That's the ultimate light meter, the eyeball.
 
morgan_moore said:
David. I thought this was a pretty light (hearted) thread.

Being serious, of course I can see the value of a light meter for pre lighting.

Genuinely over my 20 years with images I have used them or not. Shooting strobe flash and stills on transparency a meter was critical.

Once I moved to raw stills the thing got dropped, I then moved to crappy codec motion where exposure is more critical the main problems I had with choosing a camera setting is choosing the colour settings under mixed light

As an aid to that I certainly found the rgb histo a fantastic tool on the 5d and seriously missed it on the ex1 and fs100 - my displeasure with the colours on those cemeras has now 'forced' me to move to the f3 to get a more colour flexible codec - partly to make up for the info I don't have on set.

If I was going to invest in a light analysis tool above $1000 I would certainly want it to tell me something of both temp and tint..
Click to expand...


No harm... no foul Sam. I wasn't dissing you.

To be very honest, I would love to have a monitor, or camera, with a WFM, with RGB parade, and a vector scope, but just don't right now. I just can't seem to wrap my melon around histograms though. I understand the information that they show, but looking at one, for me, is like trying to do a mental math word problem and I can hear myself going, "Duh!"... It just does not instantly translate in to info that is usable for the lighting and exposure decisions I need to make. Well, not as easily as a WFM and the RGB parade do. I am shooting more run and gun with my FS-100 so I very often only have the zebra stripes and the histogram as my only exposure tools. With that camera my major issue is with the shoulder roll off and I will do my best to avoid, at almost all costs, any overexposure and let the stuff at the toe do what it may. With all of the FS-100 bashing out there, I have to give that little camera some props... I am actually quit pleased with its bottom end and really think that is were its strengths as a low light camera really are.

THAT BEING SAID, I still try my best to walk the block with my meter. Doing that solidifies in my mind exactly what is going on with the lighting. The histogram is going to tell me, for example, wow that corner is dark. My meter is going to tell me, wow, that corner is at, for example, 4 footcandles... I am two stops under, or what ever. Even if I had WFM, which, as I said, I would love to have, I would know that wow, that corner is dark and is falling below 0 IRE. Still, there is a missing part to the equation, for me; how much light is below 0 IRE? Let's say I want to bring that corner up by doubling the light there. I do not have enough experience with the electronic light tools to do that in a quick an precise way. However, I do have the light out put info for my lights, in footcandles, and I know how much light is there now, in footcandles, so I can reach into my kit and pull out the proper fixture and get it done. Of course, it is not that simple but, even with the electronic light tools, I just feel that there is a missing information that I need, or should, know; the exact quantity of light that is falling on the scene, or specific parts of the scene, in a measurement that I understand. That gives me a "Flying by the seat of my pants" feeling that makes me nervous. I understand that this reflects my inexperience with some of the more modern tools but as I gain experience with them I just can't help think a meter reading will "Connects the dots" for me to conceptualize fully what is going on with the lighting that I am dealing with. You know, X footcandles at X ISO and X f-stop equals X IRE. I may be an old timer, or what ever, but I want that.

As for color meters... Yeah, practical and available motion picture lighting is getting more and more complicated these days and I can definitely see the use for a color meter. Proper color meters are not in my budget but I have been considering picking up one of the Rotolight Spectascopes.
 
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starcentral said:
First you need to toss the manufacturers ISO rating of the cameras out the window. (I'm serious). There are at least 4 different ways of determining a digital camera's ISO within the actual ISO standard specification in itself, so an ISO on one camera will not be the same as the ISO on another camera or necessarily match your light meter. If it is, you are lucky and that's about it.

Next you need to rate the ISO of the camera yourself by using a grey card, waveform monitor, light meter and the camera. Also 1/60th shutter is not 180d in 24fps. It's actually 1/48th shutter speed and if you light meter doesn't do 1/48th (non cine-meters probably won't) then just use 1/50th. Its not a huge variation but its nice to be as close as possible.


Rate your camera properly and try your test again. I find it hard to believe that 1 stop on your lens took your skin from 60IRE to 100IRE?
Click to expand...

Thanks for the reply. Do you have any references you can share on the steps necessary to determine my camera's ISO? I'll look around. Here's something I don't get: how is it that a camera has a single ISO? The ISO is variable. I've hear that the Alexa is rated at 800 ISO but you can set the ISO to ... well whatever so is it actually an offset that you want to get?

It was actually 2 stops from 60 to 100 IRE, f2 to 4. I wrote the wrong value in my post.
 
indiawilds said:
Which light meters do you guys use.

With an app in your iphone you can have a director's viewfinder.

Waveform monitor and vectroscope in camera are good tools. I don't hear anyone mentioning vectroscope here.
Click to expand...

I use a Sekonic L-398, which I have used for well over 20 years. I also just picked up a Pentax Spotmeter V which I got off of eBay for a great price.

I am becoming more and more of a fan of a vectorscope, from the post grading that I am doing, and I would like to have one in camera or on an on set monitor. They look like a targeting computer in a jet fighter and THAT IS COOL!! ... just kidding, of course, but they give you a lot of information. While I would like to have one available I don't really think that would change the decision making that I would do using other tools.
 
How would you use a vectorscope on set except as an elaborate white balance tool? It could tell you if your red was true red, your skin tones bang on etc. Is that it? Can cameras record illegal colors (i.e. too saturated?) What would you do if saw the red light in a scene was illegal? Mess with cam matrices to bring it down?
 
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