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21st July 2015, 09:39 AM
#1
Metering & exposure - color space. Confused
Hi, I am hoping and looking for a answer that I am not sure about or just confused.
Q1: Dose Camera metering & exposure have any effect on the colour of the photo. As I read and try to find answers I get more confused. I don’t think so. Exposure is just light contrast, dark and light. Am I right or wrong?
Q2: In the tutorial in (CAMERA METERING & EXPOSURE) tutorials it’s say that if you are spot metering you should use a cray card. Dose that mean for the color or exposure. So if you are not spot metering you don’t need a cray card? why if so.
I have been using spot metering 99% of the time and I am happy with the results.
Q3: Would I get a better color space by going to partial meriting, center-Weighted.
looking forward to understand and straightening my mind.
Tank if you have helped answering this.
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21st July 2015, 11:46 AM
#2
Re: Metering & exposure - color space. Confused
Trevor,
I am going to start with the more useful but not quite correct answer.
Consider metering and color as entirely separate things. Metering is intended to help you set exposure, and nothing else. Changing metering modes simply tells the camera which areas of the scene to consider in setting the exposure. There is no one rule about the effects of switching from one mode to another. It depends on the scene.
Exposure is a single value, so it is not about contrast. It is simply how much light you are letting hit the sensor. You could have two scenes with identical proper exposure but very different contrast. One might go from true black to true white, while the other could be all gray.
Gray cards can serve two purposes, although some are designed to serve both. Some are designed to give you neutral color, that is, to help you set white balance. A well-known example of this is the whiBal series, which I use. The other function is to give you the appropriate darkness for metering correctly. I forget which it is in the digital world, either 12% or 18% gray.
Now for the complication. Suppose you shot a scene in which there are very bright reds and very dark greens. You then take a second, much darker exposure. The greens may seem to disappear into the shadows, but the reds wouldn't. You could have an image in which the reverse is true. So yes, exposure can affect the perception of color balance, but for starting out (which I think is where you are), I would put this aside for now.
Dan
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21st July 2015, 12:51 PM
#3
Re: Metering & exposure - color space. Confused
Can't argue with Dan's explanation. My shooting in manual mode based on a RGB histogram
and "exposing to the right" essentially does away with metering per say.
Proper, spot-on colors, can be achieved by using an XRite Passport during the shoot.
They are independent of exposure, assuming that it was correct to begin with.
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21st July 2015, 12:52 PM
#4
Re: Metering & exposure - color space. Confused
Thank you Dan and Grumpy for your replies. I am seeing the light.
I am also reading on the site great site.
So a file / photo in raw has no colour. Until it's converted So the colour image we see in the view finder is a jpeg and that fine but then it's and lets say LR when it imports a Raw file converts it to what ever we set Lr to AdobeRGB or SRGB and magic happens we get a colour image.
Am I then thinking right that the colour space I set in the camera has no importance As I am shooting Raw?
and just a hang on question If I am getting a little green edge on the skin tones it's called Chromatic Aberration in LR comes from what. How would I avoid that?
many thanks getting a lot clearer in my head.
Last edited by herbie53; 21st July 2015 at 03:34 PM.
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21st July 2015, 12:53 PM
#5
Moderator
Re: Metering & exposure - color space. Confused
Welcome to CiC Trevor.
1. Colour space and metering can be viewed as independent issues. Your camera does all its work in capturing an image without a colour space. A colour space is only assigned when an image file is created (JPEG, Tiff); raw data has no colour space.
2. Your camera uses a reflective light meter and "assumes" a middle gray (18%) value for whatever is being metered. By placing an 18% gray target into the same light that your subject is you will be able to determine the "proper " exposure for the scene, regardless of the actual makeup of the scene. In general this technique is used for portraiture or product photography. Often this type of shot will be done in manual mode, with the exposure dialled into the camera.
3. In general, using a spot reading will not give you a properly exposed scene, as your exposure will be made based on the assumption that your metering point represents 18% gray. If this is not reasonably correct or if you do not compensate, then your exposure can be off by a considerable amount. While I do use spot metering for specific photography situations, I find that matrix metering is my default metering mode.
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21st July 2015, 03:36 PM
#6
Re: Metering & exposure - color space. Confused
Hi GrumpyDiver, thanks for replying please see the post above as I did the reply wrong.
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21st July 2015, 09:45 PM
#7
Moderator
Re: Metering & exposure - color space. Confused
You are correct about the colour space, BUT some of the jpeg presents that you have set your camera to (things like White Balance) will be in the EXIF data that comes across with the raw data and will be applied by Lightroom. You can always change these values.
Chromatic Aberration (CA for short) is a property of your lens (design) and other than fixing it in post, there is nothing you can do about it.
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21st July 2015, 10:38 PM
#8
Re: Metering & exposure - color space. Confused
Well I did not know that about CA Thanks
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