I have just bought a Sekonic L-758DR Cine (http://www.sekonic.com/products/products.asp?ID=130) lightmeter. However, I am not sure how to properly set it for use with my Canon XL-H1. Digital Cameras have ISO values but the Canon XL-H1 has not. Does someone know what is the ISO value of the Canon XL-H1 with gain set to -3 or 0? Also, the increment from -3 0 3 6 12 18 in gain... how does that translate to ISO?

The only other option will be to achieve it through extensive testing in a controlled environment. How can I setup such a test?

The meter works great and has great features but I only need to know how to create a profile that will match my Canon XL-H1!

Floris: There have been previous posts about this, I think someone came up with ASA 320 or so... but I don't believe it,, not because I think it's wrong, but because it's apples and oranges..

I have 2 Spectra meters, old and new style, and even they don't always agree (a man with a watch always knows what time it is - a man with two watches is never sure)...

Although I have never done an actual exposure test myself, I will say this - When I shoot film (Eastman/ASA 100 or Fuji/ASA 125), I can often shoot in pretty dim interiors at T2.4 and get a decent print.. when I shoot a similar interior with the H1 @ F1.6, the image is dark.. Now that doesn't equate to ASA 320 in my book... (notice I said "T" and "F" - I went into this several posts ago, and in this instance it's important to understand the difference).

Plus, as I've mentioned in that same post, the 6x seems a half stop to a full stop below the 20x @ F1.6... So it is the light gathering capability of the camera + the lens that matters...

What you need to do is shoot a series of tests yourself, using your meter as a reference, in a variety of different lighting conditions... I think that you will find that the ASA (I prefer that term, by the way) will probably be different for different situations, even with the ND and GAIN set the same...

AND, if you have the 6x WA, you will need to repeat each situation with that lens as well.. then again at -3G - and so on...

I forgot to point out one small problem in the evaluation process.. (I'm not trying to discourage you, because using a meter is a good thing) but even with the new firmware update there is no specific marking for the values between full stops - ie F3.4 or 4.5 etc - (I sure wish there was) you have to count changes as you turn the dial and guess...

It would probably be easiest to set up a situation where you can control the light source accurately with a dimmer... fill the frame with an 18% gray card, dim the light till you get a true 1.6 in the H1 finder.. then take a reading with your meter, set the F @ 1.6 and turn the ISO dial until it matches.. then do the same for 2 and so on...

I'll be interested to hear what you discover, because I'm curious too - but too lazy to do anything about it...

Hmmm... I guess I will have to setup such a test then.

Why not just hook the camera up to a waveform monitor? Most NLEs provide one.

Doug: I don't know about Floris, but I'm an old film guy... and (as an ex-rabid surfer) to me a waveform monitor is a friend that calls you at 5 in the morning and tells you it's 8-10 feet with perfect shape off the point....

Sorry, couldn't resist, but it IS apples and oranges...

I am using Adobe Premiere Pro 2.0. But I do not have that much knowledge about this. I have read about waveform technology but I have absolutely no idea how to configure/setup such a test.

I know how to use this lightmeter for photography but I have bought it especially for use with my Canon XL-H1 to have more consistent lighting as well as a better understanding of exposure. I am sure I am not the only one who uses a lightmeter so that is the reason why I asked this.

I can have profiles for three camera's on the lightmeter. I guess I am going to create one for the camera at -3db, 0db and +3db gain and see how that works.

The way I have done it in the past is to illuminate a gray card, fill the viewfinder with it and adjust exposure until the meter (in the VF) is centered. I then place the Sekonic at the card, and twiddle the ASA setting until I get the same EV reading as I had on the camera. As this is based on f/ stops, not T stops, it is quite possible that a different lens will give a different speed (ASA, ISO, DIN).

I can have profiles for three camera's on the lightmeter. I guess I am going to create one for the camera at -3db, 0db and +3db gain and see how that works.

Be aware, if you change the Gamma curve or Setup level your profiles should be updated. Even the color adjustments, such as R, G and B gain will affect your measurement.

Yeah, Lauri - that's basically what I meant by apples and oranges - there are so many factors to consider that it's difficult to come up with an actual across-the-board rating like you can with film....

In my case I have pretty much settled on one Scene File that I like the best, and I try to shoot as much as possible at -3 GAIN... So, theoretically I COULD come up with an ASA that would fit my shooting style...

But if you're going to go to the trouble to evaluate the camera's response so that you can use a meter, one would assume (by definition) that you want to be able to be very precise about your exposures - and about your ability to repeat them predictably...

Without an iris scale that gives you continuous true values between full stops (instead of 3 or 4 clicks), it's a crap shoot... That is a weakness of these "prosumer" lenses.. But, on the other hand, once you're comfortable with it, the camera itself works pretty well as a meter.. It's just not giving you all the feedback you might want...

I used to work with Hasselblad still cameras with handheld exposure meters. But frankly, I havn't pulled my exposure meters out of the bag since I started with the XL H1. I think the situation is a bit different with digital video.

When I worked with color reversal film for slides we had not much posibilities to adjust the photo afterwards so it was important to stay around in the middle and tried to get those 18 % reflective gray cards to look similar from photo to photo.

With digital video or audio it is different. With analog audio you could let a drum play some dB too laud and the signal was limited in a soft way so no would notice. Not so with digital; a fraction of a dB too loud and the circuits abruptly clip causing an unwanted spectrum of high frequency tones scattered around, sounding crap. You better leave some headroom to the drummer for use when he get's excited.

Similar with digital video. When the digital signal reaches level 255 in any of the colors (RGB) it cannot show any brighter. So I concentrate more at staying below and watching my zebra indicator not stripe the picture to much except at direct sun reflections, light bulbs etc which we have to sacrifice to get a suitable low end. Then I have to leave the shadows as they are if they are not extra important. I don't care if the needle in the meter is not in the center. I more avaluate the reading and compare it with the reflection of the actual subject. The signal goes into the brain computer to compare with previous experience to decide if I should adjust + or -.
I can always and easily make the footage darker in post but can never rescue a blown out snow field etc.

I more aim to use the limited reproduction span wisely rather than to reproduce a gray card with accuracy as a light meter should.

Of course there are many situatons where the above do not apply, i.e. shots with limited contrast, shots which should look like in darkness, artistic shots ... Here the brain computer needs to work harder.

And remember our eyes works relatively: Most projection screens are white, aren't they? But when you turn the projector on this white suddenly transforms to the black parts of your footage without anybody complaining.

Our eyes works by photons (light) not by darkness. We more easily see a white pixel on a black screen than a dark pixel on a white screen. It is better to hide something in the shadows than in the sunlight.

What do you think?

Steve you would have much more time to surf if you put away your light meter and plugged your camera in to a WFM. :O)

The WFM will basically give you a light reading for every part of the scene. To come close with a light meter would take hours. Personally I cannot think of any reason to use a light meter with a DV camera if you have a WFM monitor available.

Doug: as a documentary filmmaker, I'm just not that meticulous.. even when I've shot commercials in film I never use anything but an incident meter..

I know there are people who can really identify qualities in zones, and while I may have known Ansel Adams personally (I live in Monterey), and actually do have a Weston Master IV stashed away somewhere, I'm just not one of those people...

For the sake of this thread, your sollution would probably be the most comprehensive in terms of estimating exposure in relation to latitude for a camera like the H1 - but it does take some expertise...

Steve I just plug my camera into my laptop and use FCP's built in WFM. I only use it when I have control over the lighting - being able to watch the WFM as lights are moved cuts down on set-up time enourmously.

Waveform and incident light meters both have their uses during a shoot.

Light meter value example: keeping the modeling of an actor's face consistent from shot to shot - retake to retake. You meter the key side and fill side of the actor's face and maintain the same ratio/levels for the same scene location - having the ratio of key to fill change is something very time consuming to fix in post.

Waveform monitoring is a fast and thorough tool to light for the latitude you want and to quickly find hot spots you may want to knock down - great safety tool. And it also ensures overall scene consistency. I find after employing our Panasonic BT1700 monitor which as a built-in onscreen waveform meter that it's constantly being used to set lighting and exposure. Great tool which I miss when shooting in a run and gun style and relying on zebras instead.

Well Call me old fashion, but I still enjoy being able to reach for a light meter. Especially when lighting a scene before a camera and monitor ever gets near the set.

Here is a down and dirty way to spec the meter to your camera....

The first thing you need to do when using a light meter with a video camera
is calibrate the meter's ISO number to match the the camera you are using.
This can be done by flat lighting an 18 percent gray card, and then shoot the card with your camera.
Look at what the camera shows for an F-stop, for example F5.6 shooting at 1/60th of a second.
Set the light meter for the same frame reading that you are shooting with your camera,
and then take a reading with the meter.
Change the ISO number until the F-stop showing on the light meter matches the F-stop of the camera.
This will give you the ISO number for that video camera, for example ISO 320,
and will allow you to calibrate the the metering system of the camera and the light meter together.

This should get you into the ballpark.

Thanks for all the feedback. The method described by David W. Jones sounds like a good starting point. I do have a powerbook 12" with Final Cut Pro so I might be able to use the waveform monitor in there as well.

But then I first need to study the subject. I have no idea how it works.

I did some testing today with a gray card and I found the following numbers:

-3db is the equilivant of ISO 200
0db is the equilivant of ISO 320
+3db is the equilivant of ISO 400
+6dbis the equilivant of ISO 800
+12db is the equilivant of ISO 1250
+18db is the equilivant of ISO 2500+

I tested them with the default camera settings and a shutter speed of 1/50 with the mode select set to HD (50i). I also tested the Panalook custom preset and got the same results at -3db and 0db. I am sure there will be custom presets that do impact the results but I have not tested all of them yet. I am going to do more extensive testing later on. The results seem right as I heard before that the Canon XL-H1 had a ISO rating of 320.

My only question is what is the difference between -3db and 0db in terms of image quality? With -3db, the camera should rate ISO 200. So is there a penalty I pay in terms of image quality? Otherwise, I will use the -3db setting whenever possible and only go up when there is not enough light.

At least I have a good starting point now.

Interesting! Thanks for doing that work.

The only difference you should see between -3 dB and 0 dB gain settings is a bit more noise at 0. You'll have to decide for yourself whether you want the speed and can live with the noise or can't tolerate the noise and will sacrifice the speed. In well lit situations it should make very little difference which setting is used. In natural light situations look for the noise in shadow areas as that is where it will be most prevalent though in some scenes (indoor at night w/o supplemental lighting) the whole frame may be "crawling" with noise.

The strange thing is: why would they call it -3db? As I see it, -3db should have been 0db and +18db should have been +36. The minus gain number makes no sense to me. So I suspected that 0db is the lowest setting and -3db does add some trickery to go even lower. Now you have -3db which is the lowest factor... then you have the A (Auto Gain) and then 0db. I just think they could and should have done this in a different way.

I am currently shooting theatre. The play is called "Mistero Buffo" and only has white lighting. So everything is black or white to say so. I did some tests and you really see the increased noise in higher gain settings.

Like you said, the black areas are the worst in terms of grain.

"this one goes to 11..." :)

Gain is a relative thing i.e. it must always be specified relative to some reference point in the system. As we are not being told what the referernce point is the absolute gain is meaningless. It is probable that the labels represents the gain of an amplifier some where in the middle of the chain and that the numbers are the actual gain of this amplifier (i.e. the reference point is it's input). -3dB gain means that if you put 141 millivolts in you get 100 millivolts out (that's right - it doesn't amplify, it attenuates). 0 dB would mean 141 mV in gives 141 mV out, +3 dB would mean 200 mV out for 141 mV in etc.