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Matrix vs Spot Metering (Ambient lighting)

vaenkavaenka Member
edited November 2012 in portraits & people
Understand this is a topic Neil has discussed but i have couple of questions. When metering for portraits is spot metering on subject's face and in M mode give 100% exposure all the times?
Or would Matrix metering suffice . I shot the attached photograph in matrix metering and A mode and the picture is slightly under exposed. I can pull the shadows up in Post processing but how can i nail this in camera? appreciate any thoughts.

Comments

  • Vaenka,

    I'll chime in because your question points to some of the most valuable lessons I've learned from Neil. Your camera, regardless of metering mode, meters for neutral gray -- the choice of metering mode just changes the portion of the frame on which the camera meters. While the metering mode makes a difference in 'A,' it plays no role in 'M.' That is, in manual mode, you have full control over what constitutes exposure. (Note that if you're adding TTL flash, then metering mode does make a difference even when shooting manual.)

    Looking at the picture you posted, you can use your camera's meter to get correct exposure. As Neil suggests, this can be done by filling the frame with the white dress, then setting the meter about one and two-thirds stops above zero. This works because the camera will see the white dress as neutral gray, thus you need to "over expose" to make the white look white. Hope this helps.

    Justin
  • TrevTrev Moderator
    Vaenka,

    As Justin said re white dress.

    Also, the reason your camera underexposed the image, and though it was a very overcast day, it's still strongly backlit and with the white dress, the sky; the camera shut down.

    Even if you had taken an ambient exposure 'correctly' their faces would still be a bit too dark/muddy, since the light was behind them so that image would have benefited from some fill flash to clean/lighten the faces.

    But exposing correctly for the faces would have resulted in a washed out sky.
    Attached image.

    Trev

  • I would love to know what the workflow was for this image? I often have muddy skin and can't seem to find the right clean-up/fix in lr3 or cs4. Thanks! Also, what would be your "starting" point for for fill flash?

    Jen
  • TrevTrev Moderator
    edited November 2012
    Jen,

    Well, personally I only do basics in ACR or LR, those being Exposure and WB.

    With that image above, remember it was only a small res jpeg so the original RAW would be much better; but I opened that in ACR.

    Did you now you can open jpegs in ACR? With a Mac, you merely Open, choose the file, but then in the File Type you choose 'Camera RAW'; but with a PC you have to 'Open As', choose the file and then choose 'Camera RAW' from the File Type. Obviously you can open in LR anyway, but I wanted ACR as it has better smoothing capabilities.

    Anyhow, with the above image, I immediately took the exposure down by -.30 of a stop to bring back some sky detail, ignoring the rest of the image, then I use fill light of +60 to open it back up again which bought out the skin more and the buildings in the background. [Image Snap 1]

    image

    Then I looked at the histogram, checking temp as I could see/knew the skin would be still not 'clean looking' once I started editing in Photoshop; so I changed the Temp to +2 and the Tint to +3.
    [above image does not show the WB corrected, I put that in to show you the slight green tint showing on the right side of the histogram then I corrected obviously].

    Then I opened in Photoshop, and did edits opening shadows slightly more, bringing in some highlights and slightly more midtones via actions I have. All still subtle

    In the action I also have built a 'Sky' mask [blue channel] to protect the sky from when I increased the highlights, but still wanting the foreground to show up. [Image Snap 2]

    image

    Muddy/Dark Skin Fix:
    Once that was done, the faces were still slightly under for my liking, so, here is where Nik Plug-In Viveza comes in handy, by dropping a control point on her face I merely then increased brightness by around 15%, and 4% more 'Warmth' Viveza targets specific colors and leaves the rest alone.

    Then another action with my 'Dodge & Burn' set created to darken the sky slightly more and give a bit of more drama to sky and buildings in background.

    Flatten/Save.

    Sounds a lot, but I took maybe 20 seconds on image in ACR + approx. 1minute in Photoshop.

    Re starting point for fill flash; quick flash on camera probably around -1 in TTL mode, you just need a bit. If I had been shooting that scene and had off camera flash available to me, I would have exposed around .5 to .75 stop under to make sure sky was detailed, added flash to correct exposure [that being of course whatever your aperture setting is if using a light meter or judging by LCD/Histogram on back of camera.

    Trev
  • TrevTrev Moderator
    edited November 2012
    PS Jen,

    Oh, re skin, it also helps if you have a problem pic where faces/shadows are darker to always slightly overexpose the image in the first place, even having small 'blinkies' warning you on white dress blowing, that way you are shooting more for the shadows than highlights, and in RAW you can bring the exposure back down to correct levels but when you open the shadows, that will help with any noise, muddy/dark looking sections.
    :)

    Obviously if there are no dark shadows and all is fairly bright or flash, there is no need to do this.
  • Thank you for the detailed info Jcgoodson.
    Appreciate you taking the time to work on the image Trev. Really like how the subjects pop in your edit.
    I was taking part in a photo marathon when we randomly met this couple.





  • Thanks for posting your workflow. I will try some of these tips. Not sure about your actions and masking. One day I hope to wrap my brain around all of this so it takes me sec not mins on a photo. ;) I just looked into the Nic plug in, $50. Is this something valuable to your workflow? I've been hoping Santa will bring me the portraiture.

    Flash on camera body w/ a -1, is that at max sync speed? Then adjusting w/ aperture?

    Thanks for all your insight!
  • TrevTrev Moderator
    edited November 2012
    Max sync speed is what your camera's shutter will allow you to fire without going into high speed sync [different subject], and yes, then controlled via your ISO and Aperture to get correct ambient. So most cameras are 200th max sync Canon; 250th Nikon, then adjusting ISO/Aperture. Don't forget ISO plays a major part of ambient exposure and flash.

    Nik plug-ins are pretty darn good, there are several.

    Viveza 2: For dropping control points onto the image to just affect that color portion/range of the image [they are in adjustable circle sizes, drop a control point and expand/contract to affect the chosen area only]

    Nik Color Efex Pro 4: Heaps of things in there with filters, etc. etc. etc.

    Silver Efex Pro 2: Great plug-in for doing Black/White images with so many variables impossible to count.

    And more: go to site and look for tutorials.

    Are they essential? Nope.
    Are they easier to manipulate images, particularly difficult sections: Yep!
    Do I use them for all images: No, definitely not.

    I may only use them around 50-100 or so times in a complete wedding batch of around 800-1200 images I process.

    It takes a long time to learn Photoshop, and lots and lots of reading, tutorials, etc.

    And I still only know 40% I'd say, it's so vast and powerful, that I will never know it all since the upgrades always bring a new course to the dinner table.
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