Sunday, 28 November 2010

Exercise 12: Managing tone

I should take an image with both jpeg and raw so I can practice the procedure on both.

Tiff or jpeg
  • Set the black and white point, close them in until just short of clipping.
  • Assess and if necessary adjust the brightness of the mid-tones, best done by eye
  • Assess and if necessary adjust the contrast
  • If needed make corrections to localised areas
handy hints on setting black and white points

http://pcin.net/update/2007/02/21/set-your-white-and-black-point-digital-photography-tip-of-the-week/
or
http://www.cambridgeincolour.com/tutorials/levels.htm

Raw
  • Set the black and white point but make sure you set the white point first by adjusting the Exposure slider, ensure that the clipping warnings are displayed so they can be adjusted precisely.
  • Assess and if needed adjust the brightness of the midtones. Use either Exposure, Brightness and Tone Curve.
  • Assess and if needed adjust the contrast, experimenting with both Contrast and Tone Curve.
  • If necessary make corrections to localised areas.
another useful video clip

http://www.youtube.com/watch?v=yT44Nd4xnGg

RAW

Original RAW image with clipping warnings displayed.

Original RAW


















As per the recommendation the White Point was set first by adjusting the Exposure slider. This done I utilised some of the other sliders to see what effects they had on the mid tones which now needed adjusting. I found a combination of adjustments gave a desired effect including using a Tone Curve.

RAW Sliders Adjustments

RAW Tone Curve




Final RAW Image
 


















The result after making these adjustments in ACR is an image with the correct exposure and tones. Using ACR gives a high amount of control to fine tuning White and Black points and local adjustments can also be made if required.

JPEG

Original Jpeg which needed adjusting but as clipping warnings cannot be made in Photoshop all adjustments are done by eye.


Original Jpeg



The first stage to altering the White and Black points in a jpeg are to use levels, and to slide the right and left hand arrows in without losing any information. I chose to use a levels adjustment layer so any changes could be altered or fine tuned using the brush tool.

Levels Layer


Further fine tuning was made to the mid point and also adding a brightness/contrast adjustment layer.

Contrast Layer

Final Jpeg



















The final jpeg also has correct exposure and tones following the adjustments.

In conclusion I have decided that the RAW conversion offers fine tuning to a greater degree, especially as you can enable the clipping warnings. Fine adjustmenst can be made locally but as I am not proficient with thgis yet I would as mentioned in previous exercises combine adjustments in ACR and Photoshop. As this image did not require an awful lot of adjustment and as layer adjustments were used I was please with the final jpeg result. Using RAW also offers all the other benefits or retaining all original information in the file.

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