Golden Ribbon

March 27, 2014  •  Leave a Comment

 

Few simple steps to capture the beauty of the golden reflection of the Moon as it rises from the sea

 

 

From my personal point of view the Moon rising from the sea is one of the most beautiful shows that nature can exhibit us. If you are lucky enough to watch this event during the blue hour, for sure you will be dazzled from the palette of colors that paint the sky and the ocean from the blue hour turquoise to the golden orange of the Moon as it pass through the lower layer of the atmosphere. Unfortunately the camera sensor (CCD) is not always able to catch the whole range of colors in the same moment nor it is able to reproduce the way our brain splits apart every single shade. For this reason it is necessary to color correct the shot after it is made sometimes using a “White balance bracketing” directly from ACR (Adobe Camera Raw).

 

Color Handling

The original shot has been made with the following set-up:

Canon 7d, Tamron 17-50 f2.8 VC @45mm, f5.6, 20 sec, iso 200

In ACR the original white balance was determined by these vales of temperature and hues: T = 3250 °C e hue = +13.

Reading the color of the sea and the sky, far from the Moon reflection, we can say that the color is almost neutral apart from a tiny purple color cast (fig.1); in LAB: L = 5, a = 1, b = -1.

This almost neutral color is not what we expected from this landscape during the blue hour where the saturation in the cold colors should be higher.

 

Golden Ribbon as shot; the shot with the original white balanceGolden Ribbon as shot fig.1Golden Ribbon as shot; the shot with the original white balance

 

 

For this reason I decided to operate in ACR and to manual change twice the white balance creating two files one for the landscape and one for the Moon glare.

For the sea: T = 2000 °C e Hue +0.

For the reflection: T = 5250 °C e Hue +5.

 

The files have been merged in Photoshop (color space Lab) in the following way:

 

  1. Apply the first file (sea and sky) as background layer;
  2. Copy the second file in a new layer and apply a white mask;
  3. Apply the L channel;
  4. Apply a curve to the mask (fig.2) and blur (radius 30 pixel);
  5. Change the blending mode in “color”.

 

Golden Ribbon color adjustment mask used to mix together the two different white balancesGolden Ribbon color adjustment mask fig.2Golden Ribbon color adjustment mask used to mix together the two different white balances

 

 

The final result can be seen in fig.3.

 

Golden Ribbon color adjustment layered structure used to mix together the two different white balancesGolden Ribbon color adjustment fig.3Golden Ribbon color adjustment layered structure used to mix together the two different white balances

 

 

Next step is to selectively reduce the background noise:

  1. Merge down and duplicate the background layer;
  2. Apply the filter noise reduction with amount 10 for L, 5 for a and 10 for b that seems to be the worst channel of all;
  3. Apply a mask that protects the glare from the loss of details;
  4. In this case we can apply the inverted L channel and use a black brush to perfectly cover the reflection (fig.4);

In fig.5 it is possible to see a magnified detail of the background before and after the noise reduction (fig.5).

 

Golden Ribbon a comparison before - after applying the noise reduction filterGolden Ribbon Noise reduction fig.4Golden Ribbon a comparison before - after applying the noise reduction filter

 

Golden Ribbon Noise reduction magnificationGolden Ribbon Noise reduction magnification fig.5Golden Ribbon a comparison before after applying the noise reduction filter

 

 

Boosting Color and creating color variations

Small adjustments have been made on the luminosity to completely close the shadows in the cliffs on the left lower corner. Nothing have been made in the lights that are already at the maximum useful value (in RGB one channel at 245-250). Neither I made any contrast increase not to create posterisation in the shades.

I decided instead to darken the glare and to preliminarily saturate the colors in the following way:

 

  1. Apply an adjustment layer curve in multiply blending mode;
  2. Apply the luminosity mask already created in the beginning such as to control the effect only in the lighter areas;
  3. Modify the opacity of the layer to 25% to mitigate the final result (fig.6);

 

Golden Ribbon Lab multiply layer to increase saturation and contrast in the moon reflectionGolden Ribbon Lab multiply fig.6Golden Ribbon Lab multiply layer to increase saturation and contrast in the moon reflection

 

 

At this point the file was ready for the actions of Color Boost e MMM from Dan Margulis’s PPW panel after the selection of a reflection’s portion.

When the actions finished their job, I suggest the following adjustments:

  1. Modify the MMM opacity from 30% to 50% to increase the color variations;
  2. Apply a layer mask to the MMM+CB group from the L channel of the merged file;
  3. Apply a curve such as to lighten the lighter areas of the image where we want to increase the colors’ yield (fig.7);
  4. Gaussian blur the image radius 30 pixels.

 

Golden Ribbon CB and MMM - the mask used in the layerd result from CB and MMM actions of PPWGolden Ribbon MMM and CB Mask fig.7Golden Ribbon CB and MMM - the mask used in the layerd result from CB and MMM actions of PPW

 

 

In the end, the MMM+CB opacity was reduced from 100% to 40% (fig.8).

 

Golden Ribbon CB and MMM - the layerd result from CB and MMM actions of PPWGolden Ribbon CB and MMM fig.8Golden Ribbon CB and MMM - the layerd result from CB and MMM actions of PPW

 

 

 

Unsharpening

To improve the details:

  1. Flatten the layers and duplicate twice the background;
  2. On the first layer, apply a USM with amount 500, radius 3 e threshold 0;
  3. On the second layer, apply a USM with amount 300, radius 30 e threshold 0 and reduce opacity to 50%;
  4. Create a group with the two layers and apply the luminosity mask;
  5. Modify the mask with a black brush pointing out only the reflection;
  6. Reduce the group opacity to 15% such as not to over-sharpen (fig.9).

 

Golden Ribbon unsharpening mask to increase the details of the moon's glareGolden Ribbon USM fig.9Golden Ribbon unsharpening mask to increase the details of the moon's glare

 

 

Final adjustments

To fine tune the image:

  1. Apply a layer curve to increase the luminosity of the light point until it reaches 245 – 250 in one of the RGB channels;
  2. Apply a layer to point out the small stars with the same technique described in this article:

http://www.dariogiannobile.com/blog/2014/3/Moon-and-venus-rising-together

The final result can be seen in fig.10.

 

Golden Ribbon Before - final adjustment to reflection's luminosityGolden Ribbon final adjustment fig.10Golden Ribbon Before - final adjustment to reflection's luminosity

 

 

From the photographic point of view, this final image is more interesting if compared with the original one as can be seen in fig.11 but it presents some limits: the cliffs are lacking of details, some strands of grass disturb the subject and there is lot of noise in the background due to the low signal to noise ratio of the original file. Nevertheless, we have defined a workflow to increase the contrast between the cold and warm shades that the nature offers during the twilight and the dawn and that can be applied to more interesting shots….and this, let me say, is an interesting result.

 

Golden Ribbon Before - After comparison between the original file and the final imageGolden Ribbon Before - After 2 fig.11Golden Ribbon Before - After color correction a la Dan Margulis. Starting point: a cold white balance; final Point a mix of cold and warm colors

 

 

Do not forget that even the best shot you can do will not compete with the nature show itself!!

If you think that this Tutorial could be useful to other astronomy and astrophotography amateurs, please feel free to share it!!

Paint the Sky, Share your Knowledge!!

Ciao

Dario

 

www.dariogiannobile.com

www.dariogiannobile.com/blog

https://www.facebook.com/pages/Astrophotography-Behind-the-Scenes/501454273309416


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