October SIG Notes

This is month is a short look at channels in Photoshop – what they are and how to use them in different ways.

My presentation will be a short introduction for about fifteen or twenty minutes.

Pat will then explain how videos and photos shot during daylight can be changed to look as if they were shot in the dark.

So what are channels?
Whether you use PS or PE, you may remember when we looked at editing images for contrast with the levels tool, and for hue and saturation.

That was when we first came across the idea of channels in Photoshop. There were four channels in the RGB color mode – RGB, Red, Green and Blue. This is the color mode that we use 90% of the time in Photoshop for editing images.

They looked like this in the levels tool. Ring any bells?

Levels with channels dialogue

Showing colour channels in a levels adjustment layer.

A bit of theory – colour spaces
Since the colours that you  see on your monitor are different from those that you see on a printed photo, PS and PE provide several ways to ensure that what you see on your screen will print as close as possible on paper.

You can find these by clicking on Image/Mode. Here is what you get:

Image-Mode dialogue

Colour modes available in Photoshop.

Normally, we will only use the four modes:

  1. rgb (screen)
  2. cymk (print)
  3. grayscale (black and white)
  4. lab (mystery of god) – to increase vibrance and saturation

What are we learning about today?

I would like to show you a quick way to add more colour to your photos.

We are in that area where there are several different ways of doing this. So if you know an easier way to add colour (other than using a crayola), please let us know by adding your favourite way as a comment.

What does it look like? It is easier to go to a website and show you –  http://www.chromasia.com/tutorials/online/lcm1_info.php .


That is about all that we are going to see because it costs $60 a year to sign up to use the site.

Exercise 1 – Using the lab channel for non destructive editing to give an image more punch.

(1) Open a photo that you like in PS.

(2) Click on Image/Duplicate.

(3) Name the new image in a way that you know it is a copy and not the original. Or just click OK to have the same name with the word copy added to the end of it. I named my copy as WIP Orchids from Garden World on September 13, 2014 by Bill copy.jpg, I figure that with WIP (Work in Progress) at the start of the file name and copy at the end of the file name, then I should be able to recognise it as the one that I want to work on!

Mine looks like this:

Opening orchid image in PS as a copy.

Click here to see actual size image.

(4) Now close the original file.

(5) Do a Save As with the file and save it in a tiff file format so that we can use this lab channel technique to increase the saturation of the colors in the image. This technique will not work with images in the jpg file format.

(6) Click on Image/Mode/Lab Color.

(7) Click on Layer/New Adjustment Layer/Levels and name it  Boost Saturation. It should look like this:

Saturation boost Levels and Lab channels

Added Levels layer and named it Boost Saturation. Showing three channels of Lab colour mode.

(8) Notice that we now have only three channels – Lightness, a and b. First step is to look at these one at a time and decide which one that you like best for looks. This is a matter of your personal taste.

We are going to change the set points for the darks and lights in channels a and b by an equal set amount so that we increase the saturation. In this case, the 0 increases to 30 while the 255 decreases to 225. Now it looks like this.

Image 5 - add 30 and subtract 30

Change 0 to 30 and 255 to 225. This gives you a boost in saturation.

Have a play with other amounts (10, 20, 40, etc.) and you may find a setting that you like better for your particular photo.

(9) Click on the a channel.

(10) Change the 0 to 30. This will increase the darkness of the greens in the image.

(11) Change the 255 to 225. This will increase the saturation of the reds in the image. Here is what I have now.

Image 3 - Orchids from Garden World on September 13, 2014 by Bill

I make sure the the increase and decrease in the dark and white set points is the same. Otherwise, the colour balance will be thrown out of whack for the photo.

(12) Repeat steps (9) to (11) for the b channel. Changing from 0 to 30 will increase the blues while changing from 255 to 225 will bring out the yellows.

(13) Preview your image by clicking on the evil eyeball of death.

(14) Now that you are happy with the increased color saturation, change back to RGB mode and do another Save As either a jpg (screen) or as a tif (print).

Watch a video!

This shows how to use the Curves tool, layers and blend modes to do the same thing we tried with levels.

 Exercise 2 – down and dirty with Lab Color Mode

Repeat Steps 1 – 6 from Exercise 1 with a different photo.

Exercise 2 CBG October 3, 2014

Taken with camera phone at Cranbourne Botanical Gardens on October 3, 2014. Notice that I did not mention it was not an iPhone!

(7) Click on Image/Apply Image.

Exercise 2 Image-Apply Image

(8) Pick one of the four channels that you like best. As you select a channel, remember to use the preview button for a quick look at before and after.

Exercise 2 Pa channel

(9) Set the blend mode to soft light. Once again, this is a good time to play with the other modes and to see what you can come up with.

(10) Done!

(11) Complete the rest of the steps in your work flow to produce a great image ready to upload on Twitter, Facebook, Pinterest, and Flickr.

(12) This is only one of the ways that channels may be used.  In November, we will look at how channels can be used to simplify selections like a tree branch or fly away hair that would be difficult to select with the normal tools (Quick Selection tool, Magic Wand tool, etc.)

For more info, try these resources:

(1) http://www.oneil.com.au/pc/photoshop/UsingPhotoshop4-Colours.pdf

(2) Detailed explanation of the different color modes and what they look like when printed.  http://www.graphics.com/article-old/photoshop-fundamentals-working-different-color-modes

(3) Good explanation of why it helps to shoot in camera raw and edit in 16 bit mode rather than shoot in jpeg and edit in  8 bit mode.  http://www.photoshopessentials.com/essentials/16-bit/

(4) For easily readable information and new ideas to try,  you cannot go wrong with Jack Lowe’s Digital Basics website – http://www.digital-photography-workflow-basics.com/photoshop-channels-tutorial.html .

(5) Masking with channels – revises topics that we have looked at previously|

(6) Scott Kelby’s Seven-Point System for Photoshop CS3 – I wished that I had seen this a few months ago. It would have saved me hours of time reading and applying his book! Here is the link: https://2014photoshopsig.files.wordpress.com/2014/10/7-pointsystemworkbook.pdf

November PS/PE Challenge

Use one of your own photos and Lab color mode to boost the colors in your image. Have a play with the blend modes to see what lurid effects that you can come up with.

Print off a few copies and take them down to the local craft market and sell them confidently for $15 a piece!

Please send your  before and after jpg image/s  to me at (photoshop@ausom.net.au).

That’s all, folks!

Pat’s Presentation at the October Photoshop SIG

Day to Night ? Converting a daylight image to a night-time shot, a very quick over-view of the process.

Here is what we are doing in changing from daylight night

Image 1 - Day to Night Colour Version

Day to Night Colour Version


Image 2 - Day to Night Black and White Version

Day to Night Black and White Version

This process is more prevalent than you think. In the film industry few night shots, particularly out-door scenes, are actually shot at night. Day shots, being easier to take and containing more detail, are then reworked.

To try this transformation, first pick the right image. Avoid bright sunlit scenes with strong shadows, choose overcast conditions that still have plenty of light and remember that shadows are far easier to put in than take out.

Start by looking at what actually happens to colour and light levels as night comes on. Colours are desaturated, the colour balance alters as yellows and reds contribute much to the daylight ‘warmer’ palette while the cooler night palette has a bluish cast. Contrast
increases and the scene darkens.

The super simplistic method of removing the colour, reducing the overall brightness and then adding a (often virulent) dark blue colour cast does not give good results. A successful result requires a number of manipulations and PS and PE contain the perfect tools, used
individually and mixed and matched according to the particular image and the desired final result.
The main ones are:
(1) Hue/Saturation – desaturating the colours, both in the composite RGB channel and in the six colour ranges in the dropdown menu.
(2) Colour Balance – setting the ‘temperature’ i.e.warmer or cooler.
(3) Curves is the tool for for controlling contrast and can also be used for darkening the scene.
(4) The Brightness/Contrast function does what it says.
(5) Blending Modes can be very useful for selective work on specific areas.

AND for each applied effect, use an Adjustment Layer. ALs are non-destructive. Effects and colour corrections can be made to the image in random order without altering the original, you just see what the effect will be. The ALs remain editable until the image is flattened and, before flattening, the file can be saved as a .psd and the ALs will be saved with the file.

For more information
The following list of free tutorials show different methods and bring up many points to be considered when converting an image. They also demonstrate lighting techniques. The Helen Bradley one is very good.
a/, b/, c/ technical points and Adjustment Layers.
d/ – e/ is more complex and just out of interest.

Here are the tutorials
(a) Day into Night with Photoshop Michael Hoffman TipSquirrel (http://www.tipsquirrel.com/day-into-night/)

(b)  Photoshop- Convert Day to Night – YouTube – Helen Bradley (http://www.youtube.com/watch?v=dYNFFtAsu40)

(c) How to turn Day into Night in 3 simple steps | Photoshop | Beginner Annös Tutorials (http://www.bikermusic.net/music/video/how-to-turn-

(d) Photoshop Tutorial – Excellent Swap of the Day into Night Sceneries Photoshop Lady (http://www.photoshoplady.com/photoshop-
tutorial/excellent-swap-of-the-day-and-night-sceneries/). Click on ‘Play Tutorial’ to open e/

(e) Combine Stock Photography to Create a Sleepy Japanese Village in Photoshop Tony Aubé (http://design.tutsplus.com/tutorials/combine-



About woldham

Concise! Retired and loving it!
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One Response to October SIG Notes

  1. bijutoha says:

    Many thanks for many resources. Specially I liked to enjoy Masking With Channels. In 9 steps its presentation must be a powerful things we should follow them sincerely.

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