High ISO e^r processing (long-9 pix)

Discussion in 'Retouching and Post Processing' started by Chris101, Dec 9, 2005.

  1. Chris101

    Chris101

    Feb 2, 2005
    Arizona
    Because of this picture, Paul asked me to explain my low-light, high-iso exposure and processing. Rather than try to recreate the steps I took for that photo, which has a lot more steps and is much more complicated by side processes, I selected the photo below, which is has much simpler composition and content and so it needs less steps. It is from the same shoot, with a similar settings and exposure, and also uses iso 3200. It's a picture of three photographs, named Common Criminal #1, #2 and #3, and some people looking at them. The guy in the back might be the photographer:
    [​IMG]

    The photo was shot in aperture mode - I selected f/3.2 to get all three photos acceptably focused - and added two thirds of a stop as Exposure Compensation. This gave me a very bright photo, with the histogram all the way to the right wall, but not climbing it much.

    Since the photo was shot in Raw, it was first processed through ACR, where the Exposure was pulled a full stop, and the Brightness boosted to 110%. The White Balance was set to auto. Color Noise Reduction was set to 80%, Luminosity Smoothng to one and the Curve bent to add contrast by deepening the shadows, but the highlights were held on the diagonal:
    [​IMG]

    Since I didn't shoot it straight (I usually try to, but, hey...), the next step straightens the shot out with Transform:
    [​IMG]

    Notice the accentuated noise in the shadows:
    [​IMG]
    and even on the subject photographs themselves (you'll have to follow the link):
    http://homepage.mac.com/cheilman1/images/photos/etothersample/shadownoise.jpg

    To combat this, a Duplicate Layer (Layer > New > Layer via Copy) was added and set to Overlay in the Mode/Style menu of the Layers palatte:
    [​IMG]

    This layer was then Gaussian Blurred with a large radius. Anywhere from 40-250 will work - the more, the smoother, so I chose 243 pixels, and reduced the opacity of the now blurred, overlay layer to 70%:
    [​IMG]

    Notice the loss of contrast that process incurred, so I increased color contrast of the underlying image layer. This was done with the Channel Mixer by selecting red output, increasing the red channel to 160% and reducing the green and blue channels 30%, then selecting green output, and likewise boosting the green content, and reducing the red and blue content. I left the blue channel alone as it seemed strong enough:
    [​IMG]

    Parts of the image were then 'sharpened' by selectively and partially Erasing some of the blurred overlay layer, and re-adjusting the overall opacity. The image was then resized to fit the web to a width of 960 pixels:
    [​IMG]

    The image was Flattened and some local sharpening was done using the Sharpen tool at 30% strength, and a final gamma correction curve was applied to restore details in the shadows that were compressed during the resize:
    [​IMG]

    Then I ran my StampEXIF script, did a bit of spotting with the Spot Healing Brush and you get the picture you see at the top of this horrendously long post. This type of processing avoids the use of noise reduction and it's resulting plastic look. While NR is useful on many images, I find the hard edged look of natural digital grain to be an effective technique to make a photo look 'streetish'.

    Opinions?
     
    Last edited by a moderator: Mar 15, 2017
  2. MontyDog

    MontyDog

    Jan 30, 2005
    #1064 - You have an error in your SQL syntax;
     
  3. Chris101

    Chris101

    Feb 2, 2005
    Arizona
    Actually it looks longer than it takes. I have a lot of these steps actionized so I can perform much of this automatically. The erasing and sharpening are the only steps that need to be done individually.
     
  4. Thanks for taking the time to put together this tutorial. I learned something.
     
  5. Great tutorial. Thanks a lot.
     
  6. Great stuff Chris! Thanks. :smile:

    I knew about a lot of your steps, but still learned something: playing with the channel mixer the way you do! Btw, do you have any reason to blur the whole image in RGB and not blur the A and B channel in LAB mode? (I am in the process of reading Dan Margulis book: the Canyon Connendrum: great stuff, including the bit about processing with the "color-blind" folks in mind)
     
  7. Chris101

    Chris101

    Feb 2, 2005
    Arizona
    Color blind stuff, eh? Now I'm gonna have to get that book!

    I also use the a/b blur (and have an action to automate it!) but it's effect is different. While the 'glam' blur sends noise deeper into the shadow, lab blur leaves it at the same level, but makes all of the noise monochromatic. If I use them both, I do the lab blur first, then the glam blur. This seems to have a better, more pronounced, effect than the other way around.

    And thanks Phil and Muril!
     
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