Lesson 5 and Lesson 6

5. Introducing Layers

In this lesson, I am introduced to layers, Firstly, the easier way to convert a flat background into an individual layer just my clicking on the lock icon on the right-hand side of the layers panel to turn it off. I found out that the layer above with affect all the layers below it and that it's possible to customize the checkerboard pattern by going to the edit menu, then drop down to Preference and choose Transparency and Gamut. One can use the Channel Mixer Adjustment Layer to temporarily turn an image black and white and use the Brightness Contrast Adjustment Layer to turn an image into near silhouette. 

At the brush tool and painting area, I learned about the Hardness value which changes how the edge of the brush stroke look (to look soft or sharp and crisp) and also the Spacing value which affects the continuity and smoothness of the brushstroke. I also learned a new trick of painting straight line by clicking at one point, and then shift + clicking at another. 

It's possible to distinguish black from non-black pixels in an image by using the threshold adjustment layer. Luminance levels are measured from 0 to 255. 0 is black, and then 255 is white and the threshold adjustment layer works in the way whereby anything brighter than a certain value is going to turn to white, and anything darker than a certain value is going to turn to black.

This lesson also demonstrates how to use the crop tool to expand the canvas to make room for a new canvas and fill in any unwanted areas of transparency with a new flat background. Next, was the clipping mask and the layer mask. The clipping mask allows one to clip an adjustment layer so that it affects just the crane layer rather than all layers below it. While the layer mask allows one to hide portions of a layer that are not selected and show the portions of the layer that are selected.

Lastly, to fill a selection with color while deleting the selection at the same time, press Alt+Backspace to fill the selection with the foreground color, press Control+Backspace to fill the selection with the background color and press Shift+Backspace to bring up the Fill dialog box. In order to add a non-adjacent layer to the selection, just click on one layer, then go to another layer, press the Control key and click on the empty portion of the layer but not the thumbnail. That's all for Lesson 5.

6. Saving Your Progress

Firstly, I didn't know that photoshop has an auto-saving setting which I can adjust to how often I want the program to save my work. It also a good thing to note that history is not saved together with the image file inside photoshop so one have to be extra careful and assured when abandoning unsaved changes. 

When saving as a PSD file, the As a Copy sign should be turned off and Alpha Channels, Layers, Notes, and Spot Colors should be turned on. When one turn on Maximize Compatibility, the file size will grow significantly as it is saving a flat version of the file along with a layer version. 

TIFF is is the most widely used file format for print images and that's because it's widely compatible and it features lossless compression. One can save a layered image as a TIFF file but it's recommended not to do so as it will increase the file size and most of the time people don't expect seeing layers in TIFF file. This is because when sending an image for a print, one generally wants the file size to be as small as possible.Thus when saving as a TIFF file, Alpha Channels and As a Copy can be turned on and Layers can be turned off. LZW, the lossless compression scheme can be turned on as it doesn't hurt the image unlike lossy compression as is associated with JPEG, is sometimes bad, but not always.

As for the PNG format, which is popular in the world of design, like TIFF, supports full-color images as well as lossless compression.However, it doesn't support layers but does support transparency. Thus, when saving as a PNG file As a Copy will definitely be turned on. Set the compression to smallest/slow and interlace to none otherwise, the file's going to load oddly inside of a web browser.

Lastly for JPEG format which is ideally suited to archiving continuous tone digital photographs. It neither supports layers nor transparency and always relies on lossy compression, meaning that it has to rewrite the colors of pixels when it saves its files. Hence, in return, we will get smaller file size. When saving as a JPEG format it's recommended to set the quality setting to the absolute maximum. For the format options, Baseline Optimized will be a better choice as it applies lossless compression, which generally helps to get the file size ever so slightly smaller, and these days everything that supports JPEGs supports Baseline Optimized.