1. (optional)
   • method 1: RAW development to image with simple color correction (no sharp, no contrast process),
     1. then export as original image
   • method 2: directly export 16 bit tiff as original image
2. original image (optional in 16-bit tiff for more color pulling and pushing)
3. Clone, Fix, Retouch layers
4. Color Correction layers
5. Color Grading layers
6. duplicate result layers for sharpen and blur

ref: https://fstoppers.com/education/speed-your-retouching-six-easy-tips-75929

• watch this video first: http://tv.adobe.com/watch/the-complete-picture-with-julieanne-kost/the-advantages-of-the-dng-file-format/
• http://photo.net/learn/raw/

• ref: http://forum.luminous-landscape.com/index.php?topic=57894.msg467946#msg467946
  • “A raw file contains an image just as does a TIFF. The raw image contains data in a mosiac format, whereas the TIFF uses a separate channel for each of the RGB components. Shown below is a straight dump of a raw image as shown by Rawnalize–it looks to me like an image. However, it needs to be demosiaced by a raw converter just as the three separate channels of a TIFF need to be combined in Photoshop.”

• also for RAW file
  • it contains lens and camera info for database lookup lens correction and optional to tune any camera settings related to camera manufacture setting
  • smaller size because each pixel is actually a single 12-16bit “color” rather than three 16bit colors, thus is faster to write to disk
  • RAW quality is actually higher. TIFF export requires interpolation of color data in camera, which can cause artifacts in post.
  • RAW has more useful data when in high contrast scenes. RAW is in sensor read data linearity while TIFF is linear in the display space. For some situations a 12bit RAW will have better data (not necessarily more) than a 16bit/color TIFF made in the same camera and scene.
  • RAW guarantees data integrity. While you can overwrite a TIFF you can't do the same with RAW
  • ref: http://www.tomsguide.com/forum/56235-5-tiff

ref: * http://www.thephoblographer.com/2011/09/26/are-tiffs-and-raws-really-the-same-thing/

1. Use Pen tool to draw the outline of the object
   1. for “out of focus” or “motion blur” area, the line should be either following the inner blur radius or outer blur radius (but overall should be consistent)
2. generate a bitmap/pixel version mask from it
3. use blur brush with controlled strength to smooth out the transition area,
   1. for sharp edge, the transition area of mask should be around 0.5 to 1 pixel
   2. for blurred transition area of mask, should be manual painted to a natural level
4. then, use level edit to controlling the shrink in and out of overall transition area, (basically shifting the black and white for the grey area; so you can use dodge and burn technique as well)

• ref:
  • https://fstoppers.com/originals/frequency-separation-rehab-42129
  • https://digitalphotoshopretouching.com/blog/my-beauty-retouching-workflow

• Portrait
  • https://www.instagram.com/risa.yu/

• Whenever there is a gradient in the background in your image, make sure you are working in 16-bit color depth to avoid banding of colors.

• if you can't get a wide-angle lens like 11mm,
  you can always stitch a 180 degree panorama with several side-by-side shots taken with normal-angle lens like 28mm
• if you can't get a 18MegaPixel camera
  you can always put a grid shots of 3MegaPixel photos together.
• if you can't get a dynamic range from your sensor,
  you can always shoot mutiple shots with different exposure and stitch together.
• if you can't get a large aperture lens to create a background-blurry portrait shot,
  you can always blur the background manually in photo editing softwares.

Because

1. Wide angles lens are expensive
2. large aperture lens are expensive
3. MegaPixel sensor camera used to be expensive (my 1st camera is 3MP)
4. High sensitivity sensor camera are expensive

We achieve the same thing digitally with free photo eiditing software, Krita or GIMP.

• Moire pattern effect and AA (anti-alias) process and Low Pass filter
  • http://www.wfu.edu/~matthews/misc/DigPhotog/alias/
  • http://mansurovs.com/what-is-low-pass-filter

• Tone mapping tips: http://www.lightstalking.com/5-important-tone-mapping-tips

• Exposure Value and Exposure stops: http://www.reedbeta.com/blog/2014/06/04/artist-friendly-hdr-with-exposure-values/
• pixel brightness and exposure stops: http://www.scratchapixel.com/lessons/3d-advanced-lessons/things-to-know-about-the-cg-lighting-pipeline/0-18-stop-and-exposure-explained/

• video tut: cn TangWan: http://www.chinahunpai.com/play1435.html

• style 1 (white/cyan/contrast): (ref)
  • cleanup and sharpen
  • lighten the face before clipping (drag highlight in level)
  • cyan the shadow
  • skin soften by soft light blend of BW filter (high contrast red filter)
  • saturate facial color

• style 2 (yellow/cyan/low contrat) (ref)
  • skin: (red/yellow) - cyan - magenta - yellow - black + saturate + light
  • shadow: (blue/black) -cyan + magenta + yellow + black
  • neutral: + yellow
  • 2nd pass color tuning
  • lower highlight curve to reduce contrast
  • lighten highlight in level to brighten, middle point to balance color
  • channel mix to boost color channel a bit more
  • color contrast: white/yellow - cyan - yellow - black;

• Green Leaf to Orange Yellow Leaf
  • yellow (Abs -70% cyan=+70% red (affect light green part), -50% yellow (-saturation))
  • green (Abs -75% cyan (affect deep green part), +10% meganta (+aging+saturation), +50% yellow (+saturation))
  • black (Abs, -cyan (dark→red), -meganta(dark→green))
  • color balance: shadow+mid (+megenta); hightlight (+yellow)

• soft light look
  • 40% color-filled top layer in screen mode

• color replacement
  • paint layer with hue mode

• color style
  • white light cyan: pure, light, clean
  • orange warm: energy, warm, home
  • cyan white cold: modern, stylish, fashion

• control of Hightlight, Middle Tone, Shadow Area
  • selection method:
    • load from RGB channel (as white is more selected, dark is not selected)
    • color range (white, grey, black)
    • calculation (math way for selection making)
      • hightlight: grey in screen;
      • shadow: inverted grey in screen;
      • middle tone: grey in exlusion

• steps of a color-grading approach
  1. decide your color style
  2. make a duplicate layer - environment
     1. apply Selective Color and Color Balance and Curve to get the rough color and exposure
  3. make a duplicate layer - shadow
     1. apply Selective Color to tune the shadow to the look
     2. get Shadow Masking to that layer
  4. make a duplicate layer - highlight
     1. apply Selective Color to tune the shadow to the look
     2. get Highlight Masking to that layer
  5. make a duplicate layer - skin
     1. apply selective color to tune the skin to the look
     2. paint masking to show the skin area.
  6. apply final grading and color tunes
  7. if any parts need to be specifically tuned, duplicate and tune it seperately

• skin perfection introduction: link
  • method - channel curve mask

Of course, before any below method, please use heal brush or patch tool to fix big holes of skins

Overlay + Invert + Highpass Filter (blur) + Gaussian Blur Filter (sharp) Method

1. duplicate layer and apply overlay blend mode
2. invert layer
3. add highpass filter to blur it like 10 point setting
4. then Gaussian blur filter to sharp it a bit
5. mask

Highpass filter (3x,18), Gaussian Blur (1x, 6), Invert, Linear Light mode (corner blend option)

1. duplicate layer
2. highpass filter (3x, 18)
3. Gaussian blur filter (1x, 6)
4. Invert
5. linear light mode (corner blend option)
6. mask

Median Filter (10)

1. duplicate layer
2. Noise: Median Filter (10)
3. mask

Surface Blur Filter (5,15)

1. duplicate layer
2. Blur: Surface Blur Filter (5,15)
3. mask

Highpass Filter (10), De-saturate, Invert, Softlight/Hardlight mode

1. duplicate layer
2. highpass filter (10) to get details,
3. de-saturate to get detail line information only
4. Invert to get smooth area information only
5. softlight/hardlight mode to blend into smooth area
6. mask

Summary of all above method and theories behind it:

• ref: https://fstoppers.com/post-production/ultimate-guide-frequency-separation-technique-8699

and more scientific accurate way of detail (high frequency image data) and smooth area (low frequency image data)seperation and process

1. prepare layers:
   1. high frequency layer: fill with 50% gray
   2. low frequency layer: duplicated image with Gaussian Blur all fine detail.
2. write out into high frequency layer
   1. select high frequency layer, choose Apply Image (8 bit, Source: LowFrequencyLayer, RGB, Subtract, scale 2, offset 128)
   2. linear light mode
3. soften and even out color and tone transitions on the Low Frequency layer

• clone tool
  • steps:
    1. use 30%~50% clone the edge around it to surround it slowly to eat it out,
    2. but the things are, when tons of little oil spots, there is no clean area to clone with
    3. force the brush will cause bad brightness change overall, then you need to lower the opacity and flow of brush to ease the blends of clone
• heal brush
  • step
    1. use small brush and heal the dots out,
    2. best of heal is auto blend the brightness of the spot, but sometimes it left with a patch outline

• water bottle spread mirror for low angle sun shot

• coloring: http://www.3lian.com/edu/photoshop/pstiaose/