Bristol Photographic Society

Ashwin’s Challenge by Neil McCoubrey – 05/03/08

Three methods for recovering shadow detail
In high contrast images
 
Method 1 – The simple one!
  1. Duplicate the layer
  2. Apply Image / Adjustments / Equalise
  3. Set Blend mode to Normal or Luminosity, whichever works best. Play with Opacity & see what happens.
  4. If required add a Hue / Saturation layer and increase Saturation to recover colour.
 
Method 2 – This technique seems to work for skin tones. Using other colour Channels or mixtures of channels will be better for other subjects.
  1. Open the image
  2. Click the CHANNELS tab
  3. Turn off the Blue layer by clicking the EYE symbol
    1. The picture will look awful but this is where most of the skin tone LIGHTNESS information is contained.
  4. Click the SELECTION symbol at the bottom of the CHANNELS tab
  5. EDIT/COPY
  6. Click the EYE on the RGB Channel to restore the images colour
  7. Click the LAYERS tab
  8. Create a new, blank layer
  9. Click EDIT/PASTE 
  10. Click IMAGE/ADJUSTMENTS/INVERT
  11. Select COLOUR DODGE as the blending mode – You now have an image that is very much lighter in the shadow skin tones. However it is also now lacking in SATURATION
  12. If you want to lighten the shadows even more then DUPLICATE this new COLOUR DODGE layer.
    1. If the effect is now too strong pull it back by reducing the OPACITY of one COLOUR DODGE layer
  13. Add a HUE SATURATION Adjustment layer on top
  14. Increase the SATURATION until you are happy with the results.
  15. If some areas of the image are now too bright then create a LAYER MASK on one of the COLOUR DODGE layers and paint with black until you are happy.
 
Method 3 – This method is simpler to use and works across the whole image.
  1. Open the image
  2. Go IMAGE / MODE / Lab Colour – This changes from RGB mode to Lab Colour mode
  3. Click CHANNELS tab
  4. Click Channel A and B to choose which one lightens the appropriate parts of the image.
  5. With the chosen Channel highlighted click LOAD Selection
  6. EDIT / COPY
  7. Click LAB Channel to restore the colour image
  8. Click the LAYERS tab
  9. Create a new, blank layer
  10. EDIT / PASTE
  11. Set BLEND Mode of new layer to HARD LIGHT
  12. Duplicate layer
  13. Add a HUE SATURATION adjustment layer to restore saturation
  14. Add a CURVES adjustment layer to restore some contrast.
  15. Go LAYER / FLATTEN image
  16. Go IMAGE / MODE / RGB
 
Creating & Using Actions
 
Actions are used for automating common sets of actions. The process is very similar to setting a tape recorder running to record something and then you can replay it over and over again. The Actions symbols used in Photoshop are the same as on a tape recorder!
 
Here is how to record an Action to take a landscape format Photoshop file, modify its size to 1024 pixels across the width and save it as a JPEG ready for projection and then close the file.
 
 
  1. Open the Actions pallet (Alt+F9) or click its tab if it is already open.
  2. Click the “new action” icon at the bottom of the pallet. It is just right of the Dustbin.
  3. Give your Action a name replacing the default “Action 1” name.
  4. Click “Record”. From now, until you click the “Stop” button, everything you do will be recorded and repeated every time you run this Action.
  5. Next
    1. Click Layer / Flatten image – this will speed up subsequent activities on multi layered images.
    2. Click Image / Image size / 1024 / OK – this will set the width of the image to that normally used for projection.
    3. Click File / Save for Web & Devices
    4. Select JPEG and the quality level you want.
    5. Click Save
    6. Navigate to the location where you want the JPEG file saved.
    7. Click File / Close / No – WARNING! Make sure to click No when asked if you want to save as clicking yes will also apply the image size reduction to the original .psd file.

Back on the Actions pallet click the Stop Recoding icon – this is on the left side of the icons at the bottom of the pallet.

Transforms, Shadows & Reflections 

Neil McCoubrey
February 2007

Transformations – are Adobe’s way of telling you that reality is the wrong shape! J
 
I use these tools to make the image fit the shape or size I need or to emphasise different elements of the image as I require.
 
Once you have Selected the area of interest then, under the Edit / Transform menu, you will find:
 
Edit/Transform/Scale – This enables the horizontal and or vertical enlargement or reduction of the size of the Selection.
Just grab one of the 8 “Handles” (the little squares that are at each corner & ½ along each side of the Transform Selection box) and drag as required.
 
Press Shift whilst dragging the handle and the horizontal and vertical scales will grow or reduce in proportion.
Press Alt whilst dragging the handle the scales will change in proportion around a central point.
 
Edit/Transform/Rotate – Find a curved arrow at one of the corner handles, click and drag it to rotate the Selection in either direction.
Press Shift whilst doing this will accurately confine the rotation into discrete, 15o steps.
 
Edit/Transform/Skew – Enables one side of the Selection, either the horizontal or vertical, to be stretched.
Pressing Alt at the same time will cause the same effect to be mirrored on the opposite corner of the Selection.
 
Edit/Transform/Distort – is my favourite! It allows all dimensions to be independently stretched or reduced in any direction, all at the same time.
 
Note – When you stretch an image beyond the canvas size the pixels outside the canvas still exist. They are not automatically deleted! This is not a problem unless you later increase the canvas size, in which case some odd shapes will suddenly reappear. To avoid this, once you are happy with the new shape of the image, always use the crop tool to get rid of unwanted pixels that are now outside the canvas.
 
Shadows – To create a shadow for an object do the following:
 
  1. Duplicate the object layer
  2. Lower the Opacity of the upper object layer so that you can see the lower object below.
  3. Activate the lower object layer. Go Edit/Transform /Distort and change the object’s shape to be right for its own shadow bearing in mind which direction you have decided the light is coming from.
  4. Go Image/Adjust/Hue Sat. and lower the “Lightness” to get the shadow to the correct luminosity. Note – most people just reduce the Saturation to achieve a shadow but this gives a grey shadow but shadows are NOT grey!
  5. Now set the Shadow layer Blend Mode to Multiply.
  6. Go back to the upper object layer and return the Opacity to 100%.
  7. Go back to the Shadow layer and set the Opacity as required. 30-50% usually works well.
  8. Go Filter/Blur/Gaussian Blur and set to 3-10% to make the shadow more realistic. Harsh lighting requires a lower blurring factor whereas soft light would require a greater blur.
  9. Finally remember that any change to the direction of the surface on which the shadow fall requires the shape of the shadow to be Transformed to suit.
 
Reflections – If you add anything to an image you may also have to add a reflection. For example, adding a new sky into an image might require a reflection to be added to any water or windows in the image.
 
  1. Say you have added an object, then, Copy/Paste that object to give another layer copy of the object.
  2. Go Edit/Transform/Flip Horizontal. Reflections are usually upside down!
  3. Move it over the water or glass, whatever is causing the reflection, into the appropriate position.
  4. Change the Blend Mode to Multiply and adjust the Opacity as required.
  5. Add a “Layer mask” to the shadow layer.

Now, by painting with black and or white and a soft brush, you can remove or add bits of the reflection to & from different areas, as required.

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