Question about using a handheld light meter

I keep going back and forth between metering with my dome facing the camera versus the key light, and was hoping some of you may be able to provide a bit of insight.

For my measurebator setup, I used a Seconic L-358 with no exposure compensation dialed in and the dome extended, an Elinchrom RX 600, Canon 5D (set to Neutral with all settings set to zero & shooting RAW), Canon 24-70 f2.8 L, and I was shooting a Gretag Macbeth 24 square color checker chart.

The RX 600 was placed at a 45° angle to the chart and I did a separate white balance, for the difference in exposure, for each set of shots -- dome facing the camera, or facing the key light. For each set of three shots, the first shot was exactly how the chart was metered, with the second and third shots being one third stop overexposed and one third stop underexposed.

Since I shoot with Canon I decided to use the DPP software that shipped with the camera (again, all setting set to zero). I thought it would be helpful to include the RGB values from the white patch (since shooting digital I don't want to blow out my highlights), and middle gray (umm, dunno why). So I'll start with those values from the "properly" exposed images and include more if anyone thinks it would be helpful.

Properly exposed image, with dome pointed toward the key light.

White patch RGB = 236, 235, 235
Middle gray patch RGB = 129, 129, 128

Properly exposed image, with dome pointed into the lens.

White patch RGB = 244, 244, 243
Middle gray patch RGB = 142, 143, 142

Personally, I learned to meter with the dome pointing into the lens which in this case seems to give me about perfect exposure. However, I know several very accomplished photographers who meter with the dome pointed toward the key light in order to avoid blowing out highlights with digital capture.

I'd really appreciate any thoughts about my little experiment (I'm no Robert... LOL) as well as how you meter, and why.

Edit: I didn't make it clear that I'm most interested in metering for my final taking aperture for proper exposure, regardless of the number of lights used. I added this because we could go into a lengthy discussion about metering for ratios, as well, which I'd really enjoy in another discussion. But we can certainly include it here if it would be of benefit.

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FlyingPhotog wrote in post #8852950
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Hi Jay,

As an aside, I just checked out your web site and really, really like your work! Did you shoot "Matrix Cafe" via telekinesis?

George

Alex_c70 wrote in post #8853217
Hi Jay,

As an aside, I just checked out your web site and really, really like your work! Did you shoot "Matrix Cafe" via telekinesis?

George

Hi George and Thanks very much...

That was just an off the wall idea for a photo club project on Silverware.

No good flatware was harmed in the making of, I might add.

I'm sure others will reply if they feel this is wrong, but I was taught to meter this way.

1. If there is only one light, meter the dome towards the light. (If you meter the dome towards the camera in this setup, you may overexpose the side the light is hitting)

2. If there is a main light and fill light, meter the dome towards the camera.

what i have read and practiced is the dome is in when you are trying to establish the light ratios between the lights, and or background.

the dome out is for your final reading dome out facing the camera.

the sekonic blog has several videos available explaining this and other things.
very helpful

hope this helps

forgot to mention when adjusting your lights with the dome in, direct the meter to main light then to the fill light. there is a nice delta feature on the 758 that tells the ratios and i think the same feature is available on the 358.

Alex,
The MacBeth Color Checker gray scale squares are intended to be six steps between white with detail and black with detail. Their reference numbers are 238,238,233 for the white square and 103,103,102 for the neutral 5 (middle gray) square.

I find that using the dome facing the camera works best for total exposure and toward the light for ratios as mentioned.

I have experimented with setting exposure using the Blinkies on the 5D LCD. What I did was open the aperture until the white square was blinking, then closed down a 1/3 stop. That creates the most extreme "expose to the right" situation. In Lightroom the image can easily be brought to proper exposure based on the color checker squares and also adjusting the tone curve to match the squares between white and black.

Alex_c70 wrote in post #8852930
I keep going back and forth between metering with my dome facing the camera versus the key light, and was hoping some of you may be able to provide a bit of insight.

For my measurebator setup, I used a Seconic L-358 with no exposure compensation dialed in and the dome extended, an Elinchrom RX 600, Canon 5D (set to Neutral with all settings set to zero & shooting RAW), Canon 24-70 f2.8 L, and I was shooting a Gretag Macbeth 24 square color checker chart.

The RX 600 was placed at a 45° angle to the chart and I did a separate white balance, for the difference in exposure, for each set of shots -- dome facing the camera, or facing the key light. For each set of three shots, the first shot was exactly how the chart was metered, with the second and third shots being one third stop overexposed and one third stop underexposed.

Since I shoot with Canon I decided to use the DPP software that shipped with the camera (again, all setting set to zero). I thought it would be helpful to include the RGB values from the white patch (since shooting digital I don't want to blow out my highlights), and middle gray (umm, dunno why). So I'll start with those values from the "properly" exposed images and include more if anyone thinks it would be helpful.

Properly exposed image, with dome pointed toward the key light.

White patch RGB = 236, 235, 235
Middle gray patch RGB = 129, 129, 128

Properly exposed image, with dome pointed into the lens.

White patch RGB = 244, 244, 243
Middle gray patch RGB = 142, 143, 142

Personally, I learned to meter with the dome pointing into the lens which in this case seems to give me about perfect exposure. However, I know several very accomplished photographers who meter with the dome pointed toward the key light in order to avoid blowing out highlights with digital capture.

I'd really appreciate any thoughts about my little experiment (I'm no Robert... LOL) as well as how you meter, and why.

Edit: I didn't make it clear that I'm most interested in metering for my final taking aperture for proper exposure, regardless of the number of lights used. I added this because we could go into a lengthy discussion about metering for ratios, as well, which I'd really enjoy in another discussion. But we can certainly include it here if it would be of benefit.

Hi Alex,

A few things to think about initially.....
There are always differences of opinion regarding metering technique and most of that stems from who and what resource you use to learn how to meter. In other words, if you use the Sekonic light meter manual or speak to those that learned to meter using film you'll almost always be told to meter while pointing the dome towards the lens. If you listen to those that learned or grew up in the digital age then you'll be told to point the dome towards the main light source.

With digital, we don't have the latitude that film has and a well controlled highlight is crucial, whereas with film you could overexpose and have no trouble processing that in the darkroom and retaining detail without the worry of a clipped highlight. If you were shooting film and pointed the meter towards the main light source, causing you to shoot at a smaller aperture, it would quite often muddy up the midtones. With digital that is not the case.

The main light, or dominant light source in a shot is generally modeling the subject and represents the highlight side of the face, or subject. One of the most important aspects of metering and getting a proper exposure if to have a well controlled highlight that is not clipping. If you have a specular highlight on the face, that highlight is going to be clipped if you were to meter with the dome facing the lens.

Of course there are exceptions depending on where the main light is placed and whether or not there are specular highlights and this all has to factor in to the 'creative exposure' which can be quite different from the technically correct exposure.

In the experiment Alex performed, the shot that was metered with the dome pointing towards the main light source is the technically correct exposure. We generically meter for middle gray and the values for middle gray are 129, 129, 128 which are just about perfect. If you determine that the highlight is controlled but the image is not as bright as you'd like or you think you want to push the exposure then once again this is a creative decision, but if middle gray is giving you middle gray then that is a technically correct exposure.

Everyone seems to develop different methods that work or apply an offset because they feel they get better results when pushing or pulling exposure one way or another and there's nothing wrong with that, but the key is to have control over exposure using a consistent and reliable method.

Having said that, I always opt to meter with the dome facing the main light to get my taking aperture because no matter how much influence any other light source may have on the exposure, it's not as much as the main light source and the main light source if creating the highlights.

It's pretty standard procedure to lower the dome and meter each light source independently to determine ratios and individual light readings but remember that even with the dome lowered it can still see other light sources. Many people will turn off the other lights when metering one light, and while that works it can often throw readings off because contribution is important to know about and be aware of as you're determining exposure. For instance, if you have a hair light and a background light and the background light is reflecting light back towards the subject then it may very well be influencing and contributing to the light from the hair light. If you didn't have the background light on and took a reading of the hair light and then turned on the background light you could be surprised and find that the hair is 'seeing' another 1/3 or more of a stop. In smaller studios this becomes more apparent.

Regardless of meter calibration you always have to know what the meter is telling you and understand that it's a suggestion.

TMR Design wrote in post #8854093
Hi Alex,

A few things to think about initially.....
There are always differences of opinion regarding metering technique and most of that stems from who and what resource you use to learn how to meter. In other words, if you use the Sekonic light meter manual or speak to those that learned to meter using film you'll almost always be told to meter while pointing the dome towards the lens. If you listen to those that learned or grew up in the digital age then you'll be told to point the dome towards the main light source.

With digital, we don't have the latitude that film has and a well controlled highlight is crucial, whereas with film you could overexpose and have no trouble processing that in the darkroom and retaining detail without the worry of a clipped highlight. If you were shooting film and pointed the meter towards the main light source, causing you to shoot at a smaller aperture, it would quite often muddy up the midtones. With digital that is not the case.

The main light, or dominant light source in a shot is generally modeling the subject and represents the highlight side of the face, or subject. One of the most important aspects of metering and getting a proper exposure if to have a well controlled highlight that is not clipping. If you have a specular highlight on the face, that highlight is going to be clipped if you were to meter with the dome facing the lens.

Of course there are exceptions depending on where the main light is placed and whether or not there are specular highlights and this all has to factor in to the 'creative exposure' which can be quite different from the technically correct exposure.

In the experiment Alex performed, the shot that was metered with the dome pointing towards the lens is the technically correct exposure. We generically meter for middle gray and the values for middle gray are 129, 129, 128 which are just about perfect. If you determine that the highlight is controlled but the image is not as bright as you'd like or you think you want to push the exposure then once again this is a creative decision, but if middle gray is giving you middle gray then that is a technically correct exposure.

Everyone seems to develop different methods that work or apply an offset because they feel they get better results when pushing or pulling exposure one way or another and there's nothing wrong with that, but the key is to have control over exposure using a consistent and reliable method.

Having said that, I always opt to meter with the dome facing the main light to get my taking aperture because no matter how much influence any other light source may have on the exposure, it's not as much as the main light source and the main light source if creating the highlights.

It's pretty standard procedure to lower the dome and meter each light source independently to determine ratios and individual light readings but remember that even with the dome lowered it can still see other light sources. Many people will turn off the other lights when metering one light, and while that works it can often throw readings off because contribution is important to know about and be aware of as you're determining exposure. For instance, if you have a hair light and a background light and the background light is reflecting light back towards the subject then it may very well be influencing and contributing to the light from the hair light. If you didn't have the background light on and took a reading of the hair light and then turned on the background light you could be surprised and find that the hair is 'seeing' another 1/3 or more of a stop. In smaller studios this becomes more apparent.

Regardless of meter calibration you always have to know what the meter is telling you and understand that it's a suggestion.

Robert - excellent explanation.

tmalone893 wrote in post #8853440
I'm sure others will reply if they feel this is wrong, but I was taught to meter this way.

1. If there is only one light, meter the dome towards the light. (If you meter the dome towards the camera in this setup, you may overexpose the side the light is hitting)

2. If there is a main light and fill light, meter the dome towards the camera.

Hi Theron. Thanks! This was the way I was taught to meter also, when I shot film, and it worked great. With digital capture, I think I'm leaning toward dome pointed toward the key, regardless of the number of lights. I'm sort of paranoid about clipping (and losing all detail) the highlights.

Steve Wintrow wrote in post #8853695
what i have read and practiced is the dome is in when you are trying to establish the light ratios between the lights, and or background.

the dome out is for your final reading dome out facing the camera.

the sekonic blog has several videos available explaining this and other things.
very helpful

hope this helps

Thanks Steve. It didn't even occur to me to visit the Sekonic site. I'll check that out this morning.

dmward wrote in post #8853894
Alex,
The MacBeth Color Checker gray scale squares are intended to be six steps between white with detail and black with detail. Their reference numbers are 238,238,233 for the white square and 103,103,102 for the neutral 5 (middle gray) square.

I find that using the dome facing the camera works best for total exposure and toward the light for ratios as mentioned.

I have experimented with setting exposure using the Blinkies on the 5D LCD. What I did was open the aperture until the white square was blinking, then closed down a 1/3 stop. That creates the most extreme "expose to the right" situation. In Lightroom the image can easily be brought to proper exposure based on the color checker squares and also adjusting the tone curve to match the squares between white and black.

That's an approach I've never considered... looking for the blinkies then backing off the exposure. I'll have to try that and compare it to what I did yesterday.

I assume the color Checker chart reference numbers are on the website? I'll poke around while I'm looking for the video tutorials.

TMR Design wrote in post #8854093
Hi Alex,

A few things to think about initially.....
There are always differences of opinion regarding metering technique and most of that stems from who and what resource you use to learn how to meter. In other words, if you use the Sekonic light meter manual or speak to those that learned to meter using film you'll almost always be told to meter while pointing the dome towards the lens. If you listen to those that learned or grew up in the digital age then you'll be told to point the dome towards the main light source.

With digital, we don't have the latitude that film has and a well controlled highlight is crucial, whereas with film you could overexpose and have no trouble processing that in the darkroom and retaining detail without the worry of a clipped highlight. If you were shooting film and pointed the meter towards the main light source, causing you to shoot at a smaller aperture, it would quite often muddy up the midtones. With digital that is not the case.

The main light, or dominant light source in a shot is generally modeling the subject and represents the highlight side of the face, or subject. One of the most important aspects of metering and getting a proper exposure if to have a well controlled highlight that is not clipping. If you have a specular highlight on the face, that highlight is going to be clipped if you were to meter with the dome facing the lens.

Of course there are exceptions depending on where the main light is placed and whether or not there are specular highlights and this all has to factor in to the 'creative exposure' which can be quite different from the technically correct exposure.

In the experiment Alex performed, the shot that was metered with the dome pointing towards the main light source is the technically correct exposure. We generically meter for middle gray and the values for middle gray are 129, 129, 128 which are just about perfect. If you determine that the highlight is controlled but the image is not as bright as you'd like or you think you want to push the exposure then once again this is a creative decision, but if middle gray is giving you middle gray then that is a technically correct exposure.

Everyone seems to develop different methods that work or apply an offset because they feel they get better results when pushing or pulling exposure one way or another and there's nothing wrong with that, but the key is to have control over exposure using a consistent and reliable method.

Having said that, I always opt to meter with the dome facing the main light to get my taking aperture because no matter how much influence any other light source may have on the exposure, it's not as much as the main light source and the main light source if creating the highlights.

It's pretty standard procedure to lower the dome and meter each light source independently to determine ratios and individual light readings but remember that even with the dome lowered it can still see other light sources. Many people will turn off the other lights when metering one light, and while that works it can often throw readings off because contribution is important to know about and be aware of as you're determining exposure. For instance, if you have a hair light and a background light and the background light is reflecting light back towards the subject then it may very well be influencing and contributing to the light from the hair light. If you didn't have the background light on and took a reading of the hair light and then turned on the background light you could be surprised and find that the hair is 'seeing' another 1/3 or more of a stop. In smaller studios this becomes more apparent.

Regardless of meter calibration you always have to know what the meter is telling you and understand that it's a suggestion.

Hi Robert,

Thanks for taking the time to write. This is a lot of really good information. There's one thing that still confusing me a bit though. The reference values that I found (see link) for the white patch are 243, 243, 242, and for the middle gray patch 122, 122, 121.

Looking at these numbers would lead me to believe that the highlights would be perfectly exposed pointing the meter into the lens, while the mid tones would be nearly perfectly exposed pointing the meter at the main light. And, to further complicate things, I get different values depending on whether I open the images in DPP, Photoshop, or Aperture. Sigh.

Perhaps I'm over thinking this and should just make it a habit to point the meter into the main light (for my taking aperture), just to be safe?

http://www.xrite.com …re/en/ColorData​-1p_EN.pdf

Alex_c70 wrote in post #8857571
That's an approach I've never considered... looking for the blinkies then backing off the exposure. I'll have to try that and compare it to what I did yesterday.

I assume the color Checker chart reference numbers are on the website? I'll poke around while I'm looking for the video tutorials.

The problem with looking at blinkies is that you first need to test and determine what exactly they are showing. You can't assume that they represent the first instance of clipping or an average or the extreme. If you want to use the blinkies it would be advisable to run some tests, perhaps lighting a white background, and look for the point where the blinkies begin and then push that a bit. Then take those images and look at the RGB values to see exactly what you're getting. At that point you can use it as a reference or aid in adjusting exposure.